Adds most of the toolsHEADmaster

1018 files changed, 12468 insertions, 0 deletions

diff --git a/v_windows/v/old/vlib/v/checker/tests/.gitattributes b/v_windows/v/old/vlib/v/checker/tests/.gitattributes
new file mode 100644
index 0000000..20f8e01
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/.gitattributes
@@ -0,0 +1,2 @@
+*_crlf_*  binary
+*_lf_*    binary
diff --git a/v_windows/v/old/vlib/v/checker/tests/.gitignore b/v_windows/v/old/vlib/v/checker/tests/.gitignore
new file mode 100644
index 0000000..868d19e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/.gitignore
@@ -0,0 +1,4 @@
+*.v
+*.c
+!*_test.v
+!modules/**/*.v
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/a_test_file_with_0_test_fns_test.out b/v_windows/v/old/vlib/v/checker/tests/a_test_file_with_0_test_fns_test.out
new file mode 100644
index 0000000..3734061
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/a_test_file_with_0_test_fns_test.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/a_test_file_with_0_test_fns_test.vv:1:1: error: a _test.v file should have *at least* one `test_` function
+    1 | fn abc() {}
+      | ^
+Details: The name of a test function in V, should start with `test_`.
+The test function should take 0 parameters, and no return type. Example:
+fn test_xyz(){ assert 2 + 2 == 4 }
diff --git a/v_windows/v/old/vlib/v/checker/tests/a_test_file_with_0_test_fns_test.vv b/v_windows/v/old/vlib/v/checker/tests/a_test_file_with_0_test_fns_test.vv
new file mode 100644
index 0000000..45f81ae
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/a_test_file_with_0_test_fns_test.vv
@@ -0,0 +1 @@
+fn abc() {}
diff --git a/v_windows/v/old/vlib/v/checker/tests/add_op_wrong_type_err.out b/v_windows/v/old/vlib/v/checker/tests/add_op_wrong_type_err.out
new file mode 100644
index 0000000..c1c8699
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/add_op_wrong_type_err.out
@@ -0,0 +1,42 @@
+vlib/v/checker/tests/add_op_wrong_type_err.vv:3:13: error: mismatched types `Aaa` and `int literal`
+    1 | struct Aaa{}
+    2 | fn main() {
+    3 |     println(Aaa{} + 10)
+      |             ~~~~~~~~~~
+    4 |     println(10 + Aaa{})
+    5 |     println([1,2,3] + 10)
+vlib/v/checker/tests/add_op_wrong_type_err.vv:4:13: error: mismatched types `int literal` and `Aaa`
+    2 | fn main() {
+    3 |     println(Aaa{} + 10)
+    4 |     println(10 + Aaa{})
+      |             ~~~~~~~~~~
+    5 |     println([1,2,3] + 10)
+    6 |     println(10 + [1,2,3])
+vlib/v/checker/tests/add_op_wrong_type_err.vv:5:13: error: mismatched types `[]int` and `int literal`
+    3 |     println(Aaa{} + 10)
+    4 |     println(10 + Aaa{})
+    5 |     println([1,2,3] + 10)
+      |             ~~~~~~~~~~~~
+    6 |     println(10 + [1,2,3])
+    7 |     a := map[string]int
+vlib/v/checker/tests/add_op_wrong_type_err.vv:6:13: error: mismatched types `int literal` and `[]int`
+    4 |     println(10 + Aaa{})
+    5 |     println([1,2,3] + 10)
+    6 |     println(10 + [1,2,3])
+      |             ~~~~~~~~~~~~
+    7 |     a := map[string]int
+    8 |     println(a + 10)
+vlib/v/checker/tests/add_op_wrong_type_err.vv:8:13: error: mismatched types `map[string]int` and `int literal`
+    6 |     println(10 + [1,2,3])
+    7 |     a := map[string]int
+    8 |     println(a + 10)
+      |             ~~~~~~
+    9 |     println(10 + a)
+   10 | }
+vlib/v/checker/tests/add_op_wrong_type_err.vv:9:13: error: mismatched types `int literal` and `map[string]int`
+    7 |     a := map[string]int
+    8 |     println(a + 10)
+    9 |     println(10 + a)
+      |             ~~~~~~
+   10 | }
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/add_op_wrong_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/add_op_wrong_type_err.vv
new file mode 100644
index 0000000..f02798b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/add_op_wrong_type_err.vv
@@ -0,0 +1,10 @@
+struct Aaa{}
+fn main() {
+    println(Aaa{} + 10)
+    println(10 + Aaa{})
+    println([1,2,3] + 10)
+    println(10 + [1,2,3])
+	a := map[string]int
+    println(a + 10)
+    println(10 + a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/alias_array_unknown_op_overloading_err.out b/v_windows/v/old/vlib/v/checker/tests/alias_array_unknown_op_overloading_err.out
new file mode 100644
index 0000000..34cfbdb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/alias_array_unknown_op_overloading_err.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/alias_array_unknown_op_overloading_err.vv:17:7: error: undefined operation `Tuple` - `Tuple`
+   15 |     mut a := new_tuple(12, 4.5, 6.7, 6)
+   16 |     b := new_tuple(12, 4.5, 6.7, 6)
+   17 |     a -= b
+      |       ~~
+   18 |     println(a - b)
+   19 | }
+vlib/v/checker/tests/alias_array_unknown_op_overloading_err.vv:18:13: error: undefined operation `Tuple` - `Tuple`
+   16 |     b := new_tuple(12, 4.5, 6.7, 6)
+   17 |     a -= b
+   18 |     println(a - b)
+      |             ~~~~~
+   19 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/alias_array_unknown_op_overloading_err.vv b/v_windows/v/old/vlib/v/checker/tests/alias_array_unknown_op_overloading_err.vv
new file mode 100644
index 0000000..84d7034
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/alias_array_unknown_op_overloading_err.vv
@@ -0,0 +1,19 @@
+type Tuple = []f64
+
+fn new_tuple(x f64, y f64, z f64, w f64) Tuple {
+	return Tuple([x, y, z, w])
+}
+
+fn (a Tuple) + (b Tuple) Tuple {
+	mut res := []f64{len: a.len}
+	for i := 0; i < a.len; i++ {
+		res[i] = a[i] + b[i]
+	}
+	return Tuple(res)
+}
+fn main() {
+    mut a := new_tuple(12, 4.5, 6.7, 6)
+    b := new_tuple(12, 4.5, 6.7, 6)
+    a -= b
+    println(a - b)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/alias_map_unknown_op_overloading_err.out b/v_windows/v/old/vlib/v/checker/tests/alias_map_unknown_op_overloading_err.out
new file mode 100644
index 0000000..6a93514
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/alias_map_unknown_op_overloading_err.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/alias_map_unknown_op_overloading_err.vv:19:10: error: undefined operation `Map` - `Map`
+   17 |     mut a := new_map()
+   18 |     b := new_map()
+   19 |     println(a - b)
+      |             ~~~~~
+   20 |     a -= b
+   21 | }
+vlib/v/checker/tests/alias_map_unknown_op_overloading_err.vv:20:7: error: undefined operation `Map` - `Map`
+   18 |     b := new_map()
+   19 |     println(a - b)
+   20 |     a -= b
+      |       ~~
+   21 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/alias_map_unknown_op_overloading_err.vv b/v_windows/v/old/vlib/v/checker/tests/alias_map_unknown_op_overloading_err.vv
new file mode 100644
index 0000000..bea0261
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/alias_map_unknown_op_overloading_err.vv
@@ -0,0 +1,21 @@
+type Map = map[string]string
+
+pub fn new_map() Map {
+	return Map(map{
+		'23': 'str'
+	})
+}
+
+fn (a Map) + (b Map) Map {
+	str := b['23']
+	return Map(map{
+		'34': str + '12'
+	})
+}
+
+fn main() {
+	mut a := new_map()
+	b := new_map()
+	println(a - b)
+    a -= b
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/alias_type_exists.out b/v_windows/v/old/vlib/v/checker/tests/alias_type_exists.out
new file mode 100644
index 0000000..d79df8a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/alias_type_exists.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/alias_type_exists.vv:1:15: error: unknown type `Bird`
+    1 | type Pigeon = Bird
+      |               ~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/alias_type_exists.vv b/v_windows/v/old/vlib/v/checker/tests/alias_type_exists.vv
new file mode 100644
index 0000000..da63abd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/alias_type_exists.vv
@@ -0,0 +1 @@
+type Pigeon = Bird
diff --git a/v_windows/v/old/vlib/v/checker/tests/ambiguous_field_method_err.out b/v_windows/v/old/vlib/v/checker/tests/ambiguous_field_method_err.out
new file mode 100644
index 0000000..019eef5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ambiguous_field_method_err.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/ambiguous_field_method_err.vv:22:4: error: ambiguous method `test`
+   20 | fn main() {
+   21 |     b := Bar{}
+   22 |     b.test()
+      |       ~~~~~~
+   23 |     n := b.name
+   24 | }
+vlib/v/checker/tests/ambiguous_field_method_err.vv:23:9: error: ambiguous field `name`
+   21 |     b := Bar{}
+   22 |     b.test()
+   23 |     n := b.name
+      |            ~~~~
+   24 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/ambiguous_field_method_err.vv b/v_windows/v/old/vlib/v/checker/tests/ambiguous_field_method_err.vv
new file mode 100644
index 0000000..fa32755
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ambiguous_field_method_err.vv
@@ -0,0 +1,24 @@
+struct Foo {
+	name int = 5
+}
+struct Bar {
+	Foo
+	Foo2
+}
+
+struct Foo2 {
+	name string
+}
+fn (f Foo2) test() {
+	println(f)
+}
+
+fn (f Foo) test() {
+	println(f)
+}
+
+fn main() {
+	b := Bar{}
+	b.test()
+	n := b.name
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/ambiguous_function_call.out b/v_windows/v/old/vlib/v/checker/tests/ambiguous_function_call.out
new file mode 100644
index 0000000..b88ef1a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ambiguous_function_call.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/ambiguous_function_call.vv:2:2: error: ambiguous call to: `foo1`, may refer to fn `foo1` or variable `foo1`
+    1 | fn foo1(foo1 int) {
+    2 |     foo1(foo1 + 1)
+      |     ~~~~~~~~~~~~~~
+    3 | }
+    4 |
+vlib/v/checker/tests/ambiguous_function_call.vv:7:2: error: ambiguous call to: `foo2`, may refer to fn `foo2` or variable `foo2`
+    5 | fn foo2() {
+    6 |     foo2 := 1
+    7 |     foo2(foo2)
+      |     ~~~~~~~~~~
+    8 | }
+    9 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/ambiguous_function_call.vv b/v_windows/v/old/vlib/v/checker/tests/ambiguous_function_call.vv
new file mode 100644
index 0000000..2d21224
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ambiguous_function_call.vv
@@ -0,0 +1,13 @@
+fn foo1(foo1 int) {
+	foo1(foo1 + 1)
+}
+
+fn foo2() {
+	foo2 := 1
+	foo2(foo2)
+}
+
+fn main() {
+	foo1(5)
+	foo2()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/any_int_float_ban_err.out b/v_windows/v/old/vlib/v/checker/tests/any_int_float_ban_err.out
new file mode 100644
index 0000000..8b9eb5d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/any_int_float_ban_err.out
@@ -0,0 +1,45 @@
+vlib/v/checker/tests/any_int_float_ban_err.vv:1:12: error: unknown type `int_literal`
+    1 | type Foo = int_literal | float_literal
+      |            ~~~~~~~~~~~
+    2 | type Fo2 = int_literal
+    3 |
+vlib/v/checker/tests/any_int_float_ban_err.vv:2:12: error: unknown type `int_literal`
+    1 | type Foo = int_literal | float_literal
+    2 | type Fo2 = int_literal
+      |            ~~~~~~~~~~~
+    3 | 
+    4 | struct Int {
+vlib/v/checker/tests/any_int_float_ban_err.vv:5:7: error: unknown type `int_literal`
+    3 | 
+    4 | struct Int {
+    5 |     i int_literal
+      |       ~~~~~~~~~~~
+    6 |     f float_literal
+    7 | }
+vlib/v/checker/tests/any_int_float_ban_err.vv:6:7: error: unknown type `float_literal`
+    4 | struct Int {
+    5 |     i int_literal
+    6 |     f float_literal
+      |       ~~~~~~~~~~~~~
+    7 | }
+    8 |
+vlib/v/checker/tests/any_int_float_ban_err.vv:9:10: error: unknown type `int_literal`
+    7 | }
+    8 | 
+    9 | fn foo(i int_literal) int_literal {
+      |          ~~~~~~~~~~~
+   10 |     return i
+   11 | }
+vlib/v/checker/tests/any_int_float_ban_err.vv:13:11: error: unknown type `int_literal`
+   11 | }
+   12 | 
+   13 | fn foo2() int_literal {
+      |           ~~~~~~~~~~~
+   14 |     return 1
+   15 | }
+vlib/v/checker/tests/any_int_float_ban_err.vv:14:12: error: cannot use `int literal` as type `int_literal` in return argument
+   12 | 
+   13 | fn foo2() int_literal {
+   14 |     return 1
+      |            ^
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/any_int_float_ban_err.vv b/v_windows/v/old/vlib/v/checker/tests/any_int_float_ban_err.vv
new file mode 100644
index 0000000..15fab98
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/any_int_float_ban_err.vv
@@ -0,0 +1,15 @@
+type Foo = int_literal | float_literal
+type Fo2 = int_literal
+
+struct Int {
+    i int_literal
+    f float_literal
+}
+
+fn foo(i int_literal) int_literal {
+    return i
+}
+
+fn foo2() int_literal {
+    return 1
+} 
diff --git a/v_windows/v/old/vlib/v/checker/tests/append_err.out b/v_windows/v/old/vlib/v/checker/tests/append_err.out
new file mode 100644
index 0000000..4c87f24
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/append_err.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/append_err.vv:3:7: error: cannot append `string` to `[]int`
+    1 | fn main() {
+    2 |     mut l := []int{}
+    3 |     l << 'test'
+      |          ~~~~~~
+    4 |     
+    5 |     _ = l << 3
+vlib/v/checker/tests/append_err.vv:5:8: error: array append cannot be used in an expression
+    3 |     l << 'test'
+    4 |     
+    5 |     _ = l << 3
+      |           ~~
+    6 |     _ = (l << 3).len
+    7 | }
+vlib/v/checker/tests/append_err.vv:6:9: error: array append cannot be used in an expression
+    4 |     
+    5 |     _ = l << 3
+    6 |     _ = (l << 3).len
+      |            ~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/append_err.vv b/v_windows/v/old/vlib/v/checker/tests/append_err.vv
new file mode 100644
index 0000000..bc506b6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/append_err.vv
@@ -0,0 +1,7 @@
+fn main() {
+	mut l := []int{}
+	l << 'test'
+	
+	_ = l << 3
+	_ = (l << 3).len
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_append_array_type_mismatch_err.out b/v_windows/v/old/vlib/v/checker/tests/array_append_array_type_mismatch_err.out
new file mode 100644
index 0000000..0cd37f3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_append_array_type_mismatch_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/array_append_array_type_mismatch_err.vv:3:8: error: cannot append `[]int` to `[]byte`
+    1 | fn main() {
+    2 |     mut bc := []byte{}
+    3 |     bc << [0xCA, 0xFE, 0xBA, 0xBE]
+      |           ~~~~~~~~~~~~~~~~~~~~~~~~
+    4 |     println(bc)
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_append_array_type_mismatch_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_append_array_type_mismatch_err.vv
new file mode 100644
index 0000000..45de913
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_append_array_type_mismatch_err.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut bc := []byte{}
+	bc << [0xCA, 0xFE, 0xBA, 0xBE]
+	println(bc)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_builtin_redefinition.out b/v_windows/v/old/vlib/v/checker/tests/array_builtin_redefinition.out
new file mode 100644
index 0000000..da5c05d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_builtin_redefinition.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/array_builtin_redefinition.vv:7:1: error: method overrides built-in array method
+    5 | // fn (a []Abc) repeat() int { return 0 }
+    6 | // fn (a []Abc) reverse() int { return 0 }
+    7 | fn (a []Abc) map() int { return 0 }
+      | ~~~~~~~~~~~~~~~~~~~~~~
+    8 | // fn (a []Abc) slice() int { return 0 }
+    9 | // fn (a []Abc) sort() int { return 0 }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_builtin_redefinition.vv b/v_windows/v/old/vlib/v/checker/tests/array_builtin_redefinition.vv
new file mode 100644
index 0000000..809b86a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_builtin_redefinition.vv
@@ -0,0 +1,11 @@
+type Abc = int
+
+// fn (a []Abc) filter() int { return 0 }
+// fn (a []Abc) clone() int { return 0 }
+// fn (a []Abc) repeat() int { return 0 }
+// fn (a []Abc) reverse() int { return 0 }
+fn (a []Abc) map() int { return 0 }
+// fn (a []Abc) slice() int { return 0 }
+// fn (a []Abc) sort() int { return 0 }
+// fn (a []Abc) contains() int { return 0 }
+// fn (a []Abc) index() int { return 0 }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_cmp_err.out b/v_windows/v/old/vlib/v/checker/tests/array_cmp_err.out
new file mode 100644
index 0000000..885a514
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_cmp_err.out
@@ -0,0 +1,26 @@
+vlib/v/checker/tests/array_cmp_err.vv:2:26: error: only `==` and `!=` are defined on arrays
+    1 | fn main() {
+    2 |     println([2, 3, 4, 6] < [2, 5])
+      |                          ^
+    3 |     println([2, 3, 4, 6] > [2, 5])
+    4 |     println([2, 3, 1, 6] >= [3, 5, 7])
+vlib/v/checker/tests/array_cmp_err.vv:3:26: error: only `==` and `!=` are defined on arrays
+    1 | fn main() {
+    2 |     println([2, 3, 4, 6] < [2, 5])
+    3 |     println([2, 3, 4, 6] > [2, 5])
+      |                          ^
+    4 |     println([2, 3, 1, 6] >= [3, 5, 7])
+    5 |     println([2, 3, 6, 8] <= [2, 5, 8, 9])
+vlib/v/checker/tests/array_cmp_err.vv:4:26: error: only `==` and `!=` are defined on arrays
+    2 |     println([2, 3, 4, 6] < [2, 5])
+    3 |     println([2, 3, 4, 6] > [2, 5])
+    4 |     println([2, 3, 1, 6] >= [3, 5, 7])
+      |                          ~~
+    5 |     println([2, 3, 6, 8] <= [2, 5, 8, 9])
+    6 | }
+vlib/v/checker/tests/array_cmp_err.vv:5:26: error: only `==` and `!=` are defined on arrays
+    3 |     println([2, 3, 4, 6] > [2, 5])
+    4 |     println([2, 3, 1, 6] >= [3, 5, 7])
+    5 |     println([2, 3, 6, 8] <= [2, 5, 8, 9])
+      |                          ~~
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_cmp_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_cmp_err.vv
new file mode 100644
index 0000000..ec60eb9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_cmp_err.vv
@@ -0,0 +1,6 @@
+fn main() {
+    println([2, 3, 4, 6] < [2, 5])
+    println([2, 3, 4, 6] > [2, 5])
+    println([2, 3, 1, 6] >= [3, 5, 7])
+    println([2, 3, 6, 8] <= [2, 5, 8, 9])
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_declare_element_a.out b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_a.out
new file mode 100644
index 0000000..15335cc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_a.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/array_declare_element_a.vv:2:5: error: non-name `arr[0]` on left side of `:=` 
+    1 | fn main() {
+    2 |     arr[0] := 2
+      |        ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_declare_element_a.vv b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_a.vv
new file mode 100644
index 0000000..ac07498
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_a.vv
@@ -0,0 +1,3 @@
+fn main() {
+	arr[0] := 2
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_declare_element_b.out b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_b.out
new file mode 100644
index 0000000..a898165
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_b.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/array_declare_element_b.vv:3:5: error: non-name `arr[1]` on left side of `:=` 
+    1 | fn main() {
+    2 |     arr := [1, 2]
+    3 |     arr[1] := 1
+      |        ~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_declare_element_b.vv b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_b.vv
new file mode 100644
index 0000000..a87a0e5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_b.vv
@@ -0,0 +1,4 @@
+fn main() {
+	arr := [1, 2]
+	arr[1] := 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_declare_element_c.out b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_c.out
new file mode 100644
index 0000000..d6e2aaf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_c.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/array_declare_element_c.vv:3:8: error: non-name `arr[1][0]` on left side of `:=` 
+    1 | fn main() {
+    2 |     arr := [[1, 2], [0, 3]]
+    3 |     arr[1][0] := 1
+      |           ~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_declare_element_c.vv b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_c.vv
new file mode 100644
index 0000000..aacad55
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_declare_element_c.vv
@@ -0,0 +1,4 @@
+fn main() {
+	arr := [[1, 2], [0, 3]]
+	arr[1][0] := 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_element_type.out b/v_windows/v/old/vlib/v/checker/tests/array_element_type.out
new file mode 100644
index 0000000..71a50e2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_element_type.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/array_element_type.vv:2:8: error: unknown type `abc`
+    1 | fn main() {
+    2 |     _ = []abc{}
+      |           ~~~
+    3 |     _ = [2, '']
+    4 | }
+vlib/v/checker/tests/array_element_type.vv:3:10: error: invalid array element: expected `int`, not `string`
+    1 | fn main() {
+    2 |     _ = []abc{}
+    3 |     _ = [2, '']
+      |             ~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_element_type.vv b/v_windows/v/old/vlib/v/checker/tests/array_element_type.vv
new file mode 100644
index 0000000..95fd275
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_element_type.vv
@@ -0,0 +1,4 @@
+fn main() {
+	_ = []abc{}
+	_ = [2, '']
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_filter_fn_err.out b/v_windows/v/old/vlib/v/checker/tests/array_filter_fn_err.out
new file mode 100644
index 0000000..cd0b1fc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_filter_fn_err.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/array_filter_fn_err.vv:2:25: error: function needs exactly 1 argument
+    1 | fn main() {
+    2 |     a1 := [1,2,3,4].filter(fn(a int, b int) bool { return a > 0 })
+      |                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    3 |     println(a1)
+    4 |
+vlib/v/checker/tests/array_filter_fn_err.vv:5:25: error: type mismatch, should use `fn(a int) bool {...}`
+    3 |     println(a1)
+    4 |
+    5 |     a2 := [1,2,3,4].filter(fn(a string) bool { return a.len > 0 })
+      |                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    6 |     println(a2)
+    7 |
+vlib/v/checker/tests/array_filter_fn_err.vv:8:18: error: function needs exactly 1 argument
+    6 |     println(a2)
+    7 |
+    8 |     a3 := [1,2,3,4].filter(fil1)
+      |                     ~~~~~~~~~~~~
+    9 |     println(a3)
+   10 |
+vlib/v/checker/tests/array_filter_fn_err.vv:11:25: error: type mismatch, should use `fn(a int) bool {...}`
+    9 |     println(a3)
+   10 |
+   11 |     a4 := [1,2,3,4].filter(fil2)
+      |                            ~~~~
+   12 |     println(a4)
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_filter_fn_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_filter_fn_err.vv
new file mode 100644
index 0000000..27c3867
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_filter_fn_err.vv
@@ -0,0 +1,21 @@
+fn main() {
+	a1 := [1,2,3,4].filter(fn(a int, b int) bool { return a > 0 })
+	println(a1)
+
+	a2 := [1,2,3,4].filter(fn(a string) bool { return a.len > 0 })
+	println(a2)
+
+	a3 := [1,2,3,4].filter(fil1)
+	println(a3)
+
+	a4 := [1,2,3,4].filter(fil2)
+	println(a4)
+}
+
+fn fil1(a int, b int) bool {
+	return a > 0
+}
+
+fn fil2(a string) bool {
+	return a.len > 0
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_index.out b/v_windows/v/old/vlib/v/checker/tests/array_index.out
new file mode 100644
index 0000000..d2e6795
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_index.out
@@ -0,0 +1,34 @@
+vlib/v/checker/tests/array_index.vv:3:7: error: non-integer index `float literal` (array type `[2]int`)
+    1 | fn fixed() {
+    2 |     a := [1,2]!
+    3 |     _ = a[0.2]
+      |          ~~~~~
+    4 |     _ = a[1] // OK
+    5 |     _ = a[-1]
+vlib/v/checker/tests/array_index.vv:5:8: error: negative index `-1`
+    3 |     _ = a[0.2]
+    4 |     _ = a[1] // OK
+    5 |     _ = a[-1]
+      |           ~~
+    6 |     _ = a[2]
+    7 |     _ = a[1..2] // OK
+vlib/v/checker/tests/array_index.vv:6:8: error: index out of range (index: 2, len: 2)
+    4 |     _ = a[1] // OK
+    5 |     _ = a[-1]
+    6 |     _ = a[2]
+      |           ^
+    7 |     _ = a[1..2] // OK
+    8 |     _ = a[2..2] // empty, OK
+vlib/v/checker/tests/array_index.vv:9:11: error: index out of range (index: 3, len: 2)
+    7 |     _ = a[1..2] // OK
+    8 |     _ = a[2..2] // empty, OK
+    9 |     _ = a[1..3]
+      |              ^
+   10 |     _ = a[3..3]
+   11 | }
+vlib/v/checker/tests/array_index.vv:10:8: error: index out of range (index: 3, len: 2)
+    8 |     _ = a[2..2] // empty, OK
+    9 |     _ = a[1..3]
+   10 |     _ = a[3..3]
+      |           ^
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_index.vv b/v_windows/v/old/vlib/v/checker/tests/array_index.vv
new file mode 100644
index 0000000..74200ff
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_index.vv
@@ -0,0 +1,11 @@
+fn fixed() {
+	a := [1,2]!
+	_ = a[0.2]
+	_ = a[1] // OK
+	_ = a[-1]
+	_ = a[2]
+	_ = a[1..2] // OK
+	_ = a[2..2] // empty, OK
+	_ = a[1..3]
+	_ = a[3..3]
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_init_sum_type_without_init_value_and_len_err.out b/v_windows/v/old/vlib/v/checker/tests/array_init_sum_type_without_init_value_and_len_err.out
new file mode 100644
index 0000000..129d9db
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_init_sum_type_without_init_value_and_len_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/array_init_sum_type_without_init_value_and_len_err.vv:4:7: error: cannot initialize sum type array without default value
+    2 | 
+    3 | fn main() {
+    4 |     a := []Foo{len: 10}
+      |          ~~~~~~
+    5 |     println(a)
+    6 |
+vlib/v/checker/tests/array_init_sum_type_without_init_value_and_len_err.vv:7:13: error: cannot initialize sum type array without default value
+    5 |     println(a)
+    6 | 
+    7 |     fixed_a := [10]Foo{}
+      |                ~~~~~~~~~
+    8 |     println(fixed_a)
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_init_sum_type_without_init_value_and_len_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_init_sum_type_without_init_value_and_len_err.vv
new file mode 100644
index 0000000..2494d52
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_init_sum_type_without_init_value_and_len_err.vv
@@ -0,0 +1,9 @@
+type Foo = int | string
+
+fn main() {
+	a := []Foo{len: 10}
+	println(a)
+
+	fixed_a := [10]Foo{}
+	println(fixed_a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_insert_type_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/array_insert_type_mismatch.out
new file mode 100644
index 0000000..78f0a64
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_insert_type_mismatch.out
@@ -0,0 +1,56 @@
+vlib/v/checker/tests/array_insert_type_mismatch.vv:3:14: error: cannot insert `float literal` to `[]int`
+    1 | fn main() {
+    2 |     mut a := [1, 2]
+    3 |     a.insert(1, 2.3)
+      |                 ~~~
+    4 |     a.insert(1, 'abc')
+    5 |     a.insert(1, [1.1, 2.2])
+vlib/v/checker/tests/array_insert_type_mismatch.vv:4:14: error: cannot insert `string` to `[]int`
+    2 |     mut a := [1, 2]
+    3 |     a.insert(1, 2.3)
+    4 |     a.insert(1, 'abc')
+      |                 ~~~~~
+    5 |     a.insert(1, [1.1, 2.2])
+    6 |     a.insert(1, ['aa', 'bb', 'cc'])
+vlib/v/checker/tests/array_insert_type_mismatch.vv:5:14: error: cannot insert `[]f64` to `[]int`
+    3 |     a.insert(1, 2.3)
+    4 |     a.insert(1, 'abc')
+    5 |     a.insert(1, [1.1, 2.2])
+      |                 ~~~~~~~~~~
+    6 |     a.insert(1, ['aa', 'bb', 'cc'])
+    7 |     a.insert(1, [[1]])
+vlib/v/checker/tests/array_insert_type_mismatch.vv:6:14: error: cannot insert `[]string` to `[]int`
+    4 |     a.insert(1, 'abc')
+    5 |     a.insert(1, [1.1, 2.2])
+    6 |     a.insert(1, ['aa', 'bb', 'cc'])
+      |                 ~~~~~~~~~~~~~~~~~~
+    7 |     a.insert(1, [[1]])
+    8 |     a.insert(1, [[['aa']]])
+vlib/v/checker/tests/array_insert_type_mismatch.vv:7:14: error: cannot insert `[][]int` to `[]int`
+    5 |     a.insert(1, [1.1, 2.2])
+    6 |     a.insert(1, ['aa', 'bb', 'cc'])
+    7 |     a.insert(1, [[1]])
+      |                 ~~~~~
+    8 |     a.insert(1, [[['aa']]])
+    9 |     println(a)
+vlib/v/checker/tests/array_insert_type_mismatch.vv:8:14: error: cannot insert `[][][]string` to `[]int`
+    6 |     a.insert(1, ['aa', 'bb', 'cc'])
+    7 |     a.insert(1, [[1]])
+    8 |     a.insert(1, [[['aa']]])
+      |                 ~~~~~~~~~~
+    9 |     println(a)
+   10 |
+vlib/v/checker/tests/array_insert_type_mismatch.vv:12:14: error: cannot insert `[][][]int` to `[][]int`
+   10 |
+   11 |     mut b := [[1, 2, 3]]
+   12 |     b.insert(0, [[[2]]])
+      |                 ~~~~~~~
+   13 |     b.insert(0, [[[['aa']]]])
+   14 |     println(b)
+vlib/v/checker/tests/array_insert_type_mismatch.vv:13:14: error: cannot insert `[][][][]string` to `[][]int`
+   11 |     mut b := [[1, 2, 3]]
+   12 |     b.insert(0, [[[2]]])
+   13 |     b.insert(0, [[[['aa']]]])
+      |                 ~~~~~~~~~~~~
+   14 |     println(b)
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_insert_type_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/array_insert_type_mismatch.vv
new file mode 100644
index 0000000..518b44a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_insert_type_mismatch.vv
@@ -0,0 +1,15 @@
+fn main() {
+	mut a := [1, 2]
+	a.insert(1, 2.3)
+	a.insert(1, 'abc')
+	a.insert(1, [1.1, 2.2])
+	a.insert(1, ['aa', 'bb', 'cc'])
+	a.insert(1, [[1]])
+	a.insert(1, [[['aa']]])
+	println(a)
+
+	mut b := [[1, 2, 3]]
+	b.insert(0, [[[2]]])
+	b.insert(0, [[[['aa']]]])
+	println(b)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_literal_modify_err.out b/v_windows/v/old/vlib/v/checker/tests/array_literal_modify_err.out
new file mode 100644
index 0000000..eaec4f9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_literal_modify_err.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/array_literal_modify_err.vv:2:24: error: array append cannot be used in an expression
+    1 | fn main() {
+    2 |     mut nums := [1, 2, 3] << 4
+      |                           ~~
+    3 |     println(nums)
+    4 | }
+vlib/v/checker/tests/array_literal_modify_err.vv:3:2: error: `println` can not print void expressions
+    1 | fn main() {
+    2 |     mut nums := [1, 2, 3] << 4
+    3 |     println(nums)
+      |     ~~~~~~~~~~~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_literal_modify_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_literal_modify_err.vv
new file mode 100644
index 0000000..79c7f97
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_literal_modify_err.vv
@@ -0,0 +1,4 @@
+fn main() {
+	mut nums := [1, 2, 3] << 4
+	println(nums)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_map_arg_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/array_map_arg_mismatch.out
new file mode 100644
index 0000000..8e06495
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_map_arg_mismatch.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/array_map_arg_mismatch.vv:3:4: error: expected 1 argument, but got 0
+    1 | fn main() {
+    2 |     a := [1, 2, 3]
+    3 |     a.map()
+      |       ~~~~~
+    4 |     a.map(it * 2, 3)
+    5 | }
+vlib/v/checker/tests/array_map_arg_mismatch.vv:4:4: error: expected 1 argument, but got 2
+    2 |     a := [1, 2, 3]
+    3 |     a.map()
+    4 |     a.map(it * 2, 3)
+      |       ~~~~~~~~~~~~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_map_arg_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/array_map_arg_mismatch.vv
new file mode 100644
index 0000000..629707b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_map_arg_mismatch.vv
@@ -0,0 +1,5 @@
+fn main() {
+	a := [1, 2, 3]
+	a.map()
+	a.map(it * 2, 3)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_map_fn_err.out b/v_windows/v/old/vlib/v/checker/tests/array_map_fn_err.out
new file mode 100644
index 0000000..b4df650
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_map_fn_err.out
@@ -0,0 +1,41 @@
+vlib/v/checker/tests/array_map_fn_err.vv:2:22: error: function needs exactly 1 argument
+    1 | fn main() {
+    2 |     a1 := [1,2,3,4].map(fn(a int, b int) int {return a + b})
+      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    3 |     println(a1)
+    4 |
+vlib/v/checker/tests/array_map_fn_err.vv:5:22: error: type mismatch, should use `fn(a int) T {...}`
+    3 |     println(a1)
+    4 |
+    5 |     a2 := [1,2,3,4].map(fn(a string) string { return a })
+      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    6 |     println(a2)
+    7 |
+vlib/v/checker/tests/array_map_fn_err.vv:8:22: error: type mismatch, should use `fn(a int) T {...}`
+    6 |     println(a2)
+    7 |
+    8 |     a3 := [1,2,3,4].map(fn(a string) {})
+      |                         ~~~~~~~~~~~~~~~
+    9 |     println(a3)
+   10 |
+vlib/v/checker/tests/array_map_fn_err.vv:11:18: error: function needs exactly 1 argument
+    9 |     println(a3)
+   10 |
+   11 |     a4 := [1,2,3,4].map(add1)
+      |                     ~~~~~~~~~
+   12 |     println(a4)
+   13 |
+vlib/v/checker/tests/array_map_fn_err.vv:14:22: error: type mismatch, should use `fn(a int) T {...}`
+   12 |     println(a4)
+   13 |
+   14 |     a5 := [1,2,3,4].map(add2)
+      |                         ~~~~
+   15 |     println(a5)
+   16 |
+vlib/v/checker/tests/array_map_fn_err.vv:17:22: error: type mismatch, should use `fn(a int) T {...}`
+   15 |     println(a5)
+   16 |
+   17 |     a6 := [1,2,3,4].map(do_nothing)
+      |                         ~~~~~~~~~~
+   18 |     println(a6)
+   19 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_map_fn_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_map_fn_err.vv
new file mode 100644
index 0000000..50d0241
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_map_fn_err.vv
@@ -0,0 +1,30 @@
+fn main() {
+	a1 := [1,2,3,4].map(fn(a int, b int) int {return a + b})
+	println(a1)
+
+	a2 := [1,2,3,4].map(fn(a string) string { return a })
+	println(a2)
+
+	a3 := [1,2,3,4].map(fn(a string) {})
+	println(a3)
+
+	a4 := [1,2,3,4].map(add1)
+	println(a4)
+
+	a5 := [1,2,3,4].map(add2)
+	println(a5)
+
+	a6 := [1,2,3,4].map(do_nothing)
+	println(a6)
+}
+
+fn add1(a int, b int) int {
+	return a + b
+}
+
+fn add2(a string) string {
+	return a
+}
+
+fn do_nothing(a string) {
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_map_void_fn_err.out b/v_windows/v/old/vlib/v/checker/tests/array_map_void_fn_err.out
new file mode 100644
index 0000000..9bd41e1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_map_void_fn_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/array_map_void_fn_err.vv:3:12: error: type mismatch, `println` does not return anything
+    1 | fn main(){
+    2 |     array := [1,2,3,4]
+    3 |     array.map(println(it))
+      |               ~~~~~~~~~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_map_void_fn_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_map_void_fn_err.vv
new file mode 100644
index 0000000..e429c8a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_map_void_fn_err.vv
@@ -0,0 +1,4 @@
+fn main(){
+	array := [1,2,3,4]
+	array.map(println(it))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_of_interfaces_with_len_without_init.out b/v_windows/v/old/vlib/v/checker/tests/array_of_interfaces_with_len_without_init.out
new file mode 100644
index 0000000..bfd51b0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_of_interfaces_with_len_without_init.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/array_of_interfaces_with_len_without_init.vv:14:37: error: cannot instantiate an array of interfaces without also giving a default `init:` value
+   12 | 
+   13 | fn main() {
+   14 |     mut parsed_lines := []MObject{len: 9}
+      |                                        ^
+   15 |     println(parsed_lines)
+   16 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_of_interfaces_with_len_without_init.vv b/v_windows/v/old/vlib/v/checker/tests/array_of_interfaces_with_len_without_init.vv
new file mode 100644
index 0000000..d9bc2d7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_of_interfaces_with_len_without_init.vv
@@ -0,0 +1,16 @@
+interface MObject {
+	give_string() string
+}
+
+struct LeStruct {
+	le_string string
+}
+
+fn (a LeStruct) give_string() string {
+	return 'V'
+}
+
+fn main() {
+	mut parsed_lines := []MObject{len: 9}
+	println(parsed_lines)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_or_map_assign_err.out b/v_windows/v/old/vlib/v/checker/tests/array_or_map_assign_err.out
new file mode 100644
index 0000000..fca758b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_or_map_assign_err.out
@@ -0,0 +1,35 @@
+vlib/v/checker/tests/array_or_map_assign_err.vv:3:5: error: use `array2 := array1.clone()` instead of `array2 := array1` (or use `unsafe`)
+    1 | fn main() {
+    2 |     a1 := [1, 2, 3]
+    3 |     a2 := a1
+      |        ~~
+    4 |     mut a3 := []int{}
+    5 |     a3 = a1
+vlib/v/checker/tests/array_or_map_assign_err.vv:5:5: error: use `array2 = array1.clone()` instead of `array2 = array1` (or use `unsafe`)
+    3 |     a2 := a1
+    4 |     mut a3 := []int{}
+    5 |     a3 = a1
+      |        ^
+    6 |
+    7 |     m1 := map{'one': 1}
+vlib/v/checker/tests/array_or_map_assign_err.vv:8:8: error: cannot copy map: call `move` or `clone` method (or use a reference)
+    6 |
+    7 |     m1 := map{'one': 1}
+    8 |     m2 := m1
+      |           ~~
+    9 |     mut m3 := map[string]int{}
+   10 |     m3 = m1
+vlib/v/checker/tests/array_or_map_assign_err.vv:10:7: error: cannot copy map: call `move` or `clone` method (or use a reference)
+    8 |     m2 := m1
+    9 |     mut m3 := map[string]int{}
+   10 |     m3 = m1
+      |          ~~
+   11 |
+   12 |     _ = a2
+vlib/v/checker/tests/array_or_map_assign_err.vv:25:8: error: cannot copy map: call `move` or `clone` method (or use a reference)
+   23 |
+   24 | fn foo(mut m map[string]int) {
+   25 |     m2 := m
+      |           ^
+   26 |     m['foo'] = 100
+   27 |     println(m)
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_or_map_assign_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_or_map_assign_err.vv
new file mode 100644
index 0000000..517a25d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_or_map_assign_err.vv
@@ -0,0 +1,29 @@
+fn main() {
+    a1 := [1, 2, 3]
+	a2 := a1
+	mut a3 := []int{}
+	a3 = a1
+
+	m1 := map{'one': 1}
+	m2 := m1
+	mut m3 := map[string]int{}
+	m3 = m1
+
+	_ = a2
+	_ = m2
+
+	mut m := map{'foo':1}
+	foo(mut m)
+
+	_ = a3
+	_ = m1
+	_ = m2
+	_ = m3
+}
+
+fn foo(mut m map[string]int) {
+	m2 := m
+	m['foo'] = 100
+	println(m)
+	println(m2)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_prepend_type_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/array_prepend_type_mismatch.out
new file mode 100644
index 0000000..8e74b7f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_prepend_type_mismatch.out
@@ -0,0 +1,56 @@
+vlib/v/checker/tests/array_prepend_type_mismatch.vv:3:12: error: cannot prepend `float literal` to `[]int`
+    1 | fn main() {
+    2 |     mut a := [1, 2]
+    3 |     a.prepend(2.3)
+      |               ~~~
+    4 |     a.prepend('abc')
+    5 |     a.prepend([2.2, 3.3])
+vlib/v/checker/tests/array_prepend_type_mismatch.vv:4:12: error: cannot prepend `string` to `[]int`
+    2 |     mut a := [1, 2]
+    3 |     a.prepend(2.3)
+    4 |     a.prepend('abc')
+      |               ~~~~~
+    5 |     a.prepend([2.2, 3.3])
+    6 |     a.prepend(['aa', 'bb', 'cc'])
+vlib/v/checker/tests/array_prepend_type_mismatch.vv:5:12: error: cannot prepend `[]f64` to `[]int`
+    3 |     a.prepend(2.3)
+    4 |     a.prepend('abc')
+    5 |     a.prepend([2.2, 3.3])
+      |               ~~~~~~~~~~
+    6 |     a.prepend(['aa', 'bb', 'cc'])
+    7 |     a.prepend([[1]])
+vlib/v/checker/tests/array_prepend_type_mismatch.vv:6:12: error: cannot prepend `[]string` to `[]int`
+    4 |     a.prepend('abc')
+    5 |     a.prepend([2.2, 3.3])
+    6 |     a.prepend(['aa', 'bb', 'cc'])
+      |               ~~~~~~~~~~~~~~~~~~
+    7 |     a.prepend([[1]])
+    8 |     a.prepend([[['aa']]])
+vlib/v/checker/tests/array_prepend_type_mismatch.vv:7:12: error: cannot prepend `[][]int` to `[]int`
+    5 |     a.prepend([2.2, 3.3])
+    6 |     a.prepend(['aa', 'bb', 'cc'])
+    7 |     a.prepend([[1]])
+      |               ~~~~~
+    8 |     a.prepend([[['aa']]])
+    9 |     println(a)
+vlib/v/checker/tests/array_prepend_type_mismatch.vv:8:12: error: cannot prepend `[][][]string` to `[]int`
+    6 |     a.prepend(['aa', 'bb', 'cc'])
+    7 |     a.prepend([[1]])
+    8 |     a.prepend([[['aa']]])
+      |               ~~~~~~~~~~
+    9 |     println(a)
+   10 |
+vlib/v/checker/tests/array_prepend_type_mismatch.vv:12:12: error: cannot prepend `[][][]int` to `[][]int`
+   10 |
+   11 |     mut b := [[1, 2, 3]]
+   12 |     b.prepend([[[2]]])
+      |               ~~~~~~~
+   13 |     b.prepend([[[['aa']]]])
+   14 |     println(b)
+vlib/v/checker/tests/array_prepend_type_mismatch.vv:13:12: error: cannot prepend `[][][][]string` to `[][]int`
+   11 |     mut b := [[1, 2, 3]]
+   12 |     b.prepend([[[2]]])
+   13 |     b.prepend([[[['aa']]]])
+      |               ~~~~~~~~~~~~
+   14 |     println(b)
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_prepend_type_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/array_prepend_type_mismatch.vv
new file mode 100644
index 0000000..925156e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_prepend_type_mismatch.vv
@@ -0,0 +1,15 @@
+fn main() {
+	mut a := [1, 2]
+	a.prepend(2.3)
+	a.prepend('abc')
+	a.prepend([2.2, 3.3])
+	a.prepend(['aa', 'bb', 'cc'])
+	a.prepend([[1]])
+	a.prepend([[['aa']]])
+	println(a)
+
+	mut b := [[1, 2, 3]]
+	b.prepend([[[2]]])
+	b.prepend([[[['aa']]]])
+	println(b)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_sort_err.out b/v_windows/v/old/vlib/v/checker/tests/array_sort_err.out
new file mode 100644
index 0000000..04c3dbf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_sort_err.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/array_sort_err.vv:3:6: error: expected 0 or 1 argument, but got 2
+    1 | fn main() {
+    2 |     mut arr := [3, 2, 1]
+    3 |     arr.sort(a < b, a)
+      |         ~~~~~~~~~~~~~~
+    4 |     arr.sort(a == b)
+    5 |     arr.sort(a > a)
+vlib/v/checker/tests/array_sort_err.vv:4:9: error: `.sort()` can only use `<` or `>` comparison
+    2 |     mut arr := [3, 2, 1]
+    3 |     arr.sort(a < b, a)
+    4 |     arr.sort(a == b)
+      |         ~~~~~~~~~~~~
+    5 |     arr.sort(a > a)
+    6 |     arr.sort(c > d)
+vlib/v/checker/tests/array_sort_err.vv:5:9: error: `.sort()` cannot use same argument
+    3 |     arr.sort(a < b, a)
+    4 |     arr.sort(a == b)
+    5 |     arr.sort(a > a)
+      |         ~~~~~~~~~~~
+    6 |     arr.sort(c > d)
+    7 | }
+vlib/v/checker/tests/array_sort_err.vv:6:9: error: `.sort()` can only use `a` or `b` as argument, e.g. `arr.sort(a < b)`
+    4 |     arr.sort(a == b)
+    5 |     arr.sort(a > a)
+    6 |     arr.sort(c > d)
+      |         ~~~~~~~~~~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_sort_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_sort_err.vv
new file mode 100644
index 0000000..821cfd0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_sort_err.vv
@@ -0,0 +1,7 @@
+fn main() {
+	mut arr := [3, 2, 1]
+	arr.sort(a < b, a)
+    arr.sort(a == b)
+    arr.sort(a > a)
+    arr.sort(c > d)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_sort_struct_no_body_err.out b/v_windows/v/old/vlib/v/checker/tests/array_sort_struct_no_body_err.out
new file mode 100644
index 0000000..dd83a0b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_sort_struct_no_body_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/array_sort_struct_no_body_err.vv:6:5: error: custom sorting condition must be supplied for type `Foo`
+    4 | 
+    5 | mut arr := []Foo{}
+    6 | arr.sort()
+      |     ~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/array_sort_struct_no_body_err.vv b/v_windows/v/old/vlib/v/checker/tests/array_sort_struct_no_body_err.vv
new file mode 100644
index 0000000..6b53ea9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/array_sort_struct_no_body_err.vv
@@ -0,0 +1,6 @@
+struct Foo {
+	bar int
+}
+
+mut arr := []Foo{}
+arr.sort()
diff --git a/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_a.out b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_a.out
new file mode 100644
index 0000000..9f838fd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_a.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/arrow_op_wrong_left_type_err_a.vv:4:2: error: cannot push on non-channel `i64`
+    2 |     ch := i64(3)
+    3 |     obj := 5
+    4 |     ch <- obj
+      |     ~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_a.vv
new file mode 100644
index 0000000..d205205
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_a.vv
@@ -0,0 +1,5 @@
+fn main() {
+	ch := i64(3)
+	obj := 5
+	ch <- obj
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_b.out b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_b.out
new file mode 100644
index 0000000..61d6c99
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_b.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/arrow_op_wrong_left_type_err_b.vv:4:8: error: cannot assign to `obj`: expected `int`, not `string`
+    2 |     ch := chan string{}
+    3 |     mut obj := 9
+    4 |     obj = <-ch
+      |           ~~
+    5 |     _ = obj
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_b.vv
new file mode 100644
index 0000000..3e842d9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_left_type_err_b.vv
@@ -0,0 +1,6 @@
+fn main() {
+	ch := chan string{}
+	mut obj := 9
+	obj = <-ch
+	_ = obj
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_a.out b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_a.out
new file mode 100644
index 0000000..e16afc8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_a.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/arrow_op_wrong_right_type_err_a.vv:4:8: error: cannot push `string` on `chan u64`
+    2 |     ch := chan u64{cap: 10}
+    3 |     obj := 'test'
+    4 |     ch <- obj
+      |           ~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_a.vv
new file mode 100644
index 0000000..f74184d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_a.vv
@@ -0,0 +1,5 @@
+fn main() {
+	ch := chan u64{cap: 10}
+	obj := 'test'
+	ch <- obj
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_b.out b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_b.out
new file mode 100644
index 0000000..ae9be38
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_b.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/arrow_op_wrong_right_type_err_b.vv:3:9: error: <- operator can only be used with `chan` types
+    1 | fn main() {
+    2 |     ch := i64(3)
+    3 |     obj := <-ch
+      |            ~~
+    4 |     println(obj)
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_b.vv
new file mode 100644
index 0000000..48de2bf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/arrow_op_wrong_right_type_err_b.vv
@@ -0,0 +1,5 @@
+fn main() {
+	ch := i64(3)
+	obj := <-ch
+	println(obj)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/asm_immutable_err.out b/v_windows/v/old/vlib/v/checker/tests/asm_immutable_err.out
new file mode 100644
index 0000000..2153ae9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/asm_immutable_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/asm_immutable_err.vv:9:9: error: `c` is immutable, declare it with `mut` to make it mutable
+    7 |         add eax, b
+    8 |         mov c, eax
+    9 |         ; =r (c) // output 
+      |               ^
+   10 |         ; r (a) // input 
+   11 |           r (b)
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/asm_immutable_err.vv b/v_windows/v/old/vlib/v/checker/tests/asm_immutable_err.vv
new file mode 100644
index 0000000..e991206
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/asm_immutable_err.vv
@@ -0,0 +1,16 @@
+fn main() {
+	a := 100
+	b := 20
+	c := 0
+	asm amd64 {
+		mov eax, a
+		add eax, b
+		mov c, eax
+		; =r (c) // output 
+		; r (a) // input 
+		  r (b)
+	}
+	println('a: $a') // 100
+	println('b: $b') // 20
+	println('c: $c') // 120
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assert_optional_err.out b/v_windows/v/old/vlib/v/checker/tests/assert_optional_err.out
new file mode 100644
index 0000000..9d2f49a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assert_optional_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assert_optional_err.vv:4:9: error: assert can be used only with `bool` expressions, but found `void` instead
+    2 |
+    3 | fn main(){
+    4 |     assert os.truncate("testfile.txt", 6666) or { panic(err) }
+      |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assert_optional_err.vv b/v_windows/v/old/vlib/v/checker/tests/assert_optional_err.vv
new file mode 100644
index 0000000..7036616
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assert_optional_err.vv
@@ -0,0 +1,5 @@
+import os
+
+fn main(){
+	assert os.truncate("testfile.txt", 6666) or { panic(err) }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_array_init_with_no_type.out b/v_windows/v/old/vlib/v/checker/tests/assign_array_init_with_no_type.out
new file mode 100644
index 0000000..b04c3f7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_array_init_with_no_type.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/assign_array_init_with_no_type.vv:2:11: error: array_init: no type specified (maybe: `[]Type{}` instead of `[]`)
+    1 | fn main() {
+    2 |     mut x := []
+      |              ~~
+    3 |     println(x)
+    4 | }
+vlib/v/checker/tests/assign_array_init_with_no_type.vv:3:2: error: `println` can not print void expressions
+    1 | fn main() {
+    2 |     mut x := []
+    3 |     println(x)
+      |     ~~~~~~~~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_array_init_with_no_type.vv b/v_windows/v/old/vlib/v/checker/tests/assign_array_init_with_no_type.vv
new file mode 100644
index 0000000..cc06a55
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_array_init_with_no_type.vv
@@ -0,0 +1,4 @@
+fn main() {
+	mut x := []
+	println(x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_deref_fn_call_on_left_side_err.out b/v_windows/v/old/vlib/v/checker/tests/assign_deref_fn_call_on_left_side_err.out
new file mode 100644
index 0000000..d26ab1b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_deref_fn_call_on_left_side_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_deref_fn_call_on_left_side_err.vv:8:2: error: cannot dereference a function call on the left side of an assignment, use a temporary variable
+    6 |
+    7 | fn main() {
+    8 |     *foo('s') = 1
+      |     ^
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_deref_fn_call_on_left_side_err.vv b/v_windows/v/old/vlib/v/checker/tests/assign_deref_fn_call_on_left_side_err.vv
new file mode 100644
index 0000000..50aa22b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_deref_fn_call_on_left_side_err.vv
@@ -0,0 +1,9 @@
+struct Foo{}
+
+fn foo(s string) &Foo {
+	return &Foo{}
+}
+
+fn main() {
+	*foo('s') = 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_a.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_a.out
new file mode 100644
index 0000000..cba2860
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_a.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_a.vv:3:2: error: operator <<= not defined on left operand type `f64`
+    1 | fn main() {
+    2 |     mut foo := 0.5
+    3 |     foo <<= 1
+      |     ~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_a.vv
new file mode 100644
index 0000000..8ea403d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_a.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := 0.5
+	foo <<= 1
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_b.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_b.out
new file mode 100644
index 0000000..e5f01ca
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_b.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_b.vv:3:9: error: operator %= not defined on right operand type `string`
+    1 | fn main() {
+    2 |     mut foo := 10
+    3 |     foo %= 'hello'
+      |            ~~~~~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_b.vv
new file mode 100644
index 0000000..db28266
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_b.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := 10
+	foo %= 'hello'
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_c.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_c.out
new file mode 100644
index 0000000..338ce5b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_c.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_c.vv:3:2: error: operator *= not defined on left operand type `string`
+    1 | fn main() {
+    2 |     mut foo := 'hello'
+    3 |     foo *= 10
+      |     ~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_c.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_c.vv
new file mode 100644
index 0000000..98409ac
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_c.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := 'hello'
+	foo *= 10
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_d.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_d.out
new file mode 100644
index 0000000..7753629
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_d.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_d.vv:3:9: error: operator /= not defined on right operand type `bool`
+    1 | fn main() {
+    2 |     mut foo := 1.5
+    3 |     foo /= true
+      |            ~~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_d.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_d.vv
new file mode 100644
index 0000000..ca5c0ee
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_d.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := 1.5
+	foo /= true
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_e.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_e.out
new file mode 100644
index 0000000..b8acd99
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_e.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_e.vv:3:2: error: operator `-=` not defined on left operand type `string`
+    1 | fn main() {
+    2 |     mut foo := 'hello'
+    3 |     foo -= `a`
+      |     ~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_e.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_e.vv
new file mode 100644
index 0000000..b6a4473
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_e.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := 'hello'
+	foo -= `a`
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_f.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_f.out
new file mode 100644
index 0000000..7cdaa51
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_f.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_f.vv:3:9: error: invalid right operand: int -= bool
+    1 | fn main() {
+    2 |     mut foo := 10
+    3 |     foo -= false
+      |            ~~~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_f.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_f.vv
new file mode 100644
index 0000000..70213c4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_f.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := 10
+	foo -= false
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_g.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_g.out
new file mode 100644
index 0000000..e017d7b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_g.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_g.vv:3:2: error: operator `+=` not defined on left operand type `bool`
+    1 | fn main() {
+    2 |     mut foo := true
+    3 |     foo += false
+      |     ~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_g.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_g.vv
new file mode 100644
index 0000000..c9380f4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_g.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := true
+	foo += false
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_h.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_h.out
new file mode 100644
index 0000000..07d2b6e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_h.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_h.vv:3:9: error: invalid right operand: string += bool
+    1 | fn main() {
+    2 |     mut foo := 'hello'
+    3 |     foo += false
+      |            ~~~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_h.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_h.vv
new file mode 100644
index 0000000..51b2207
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_h.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := 'hello'
+	foo += false
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_i.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_i.out
new file mode 100644
index 0000000..c8450f0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_i.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_type_err_i.vv:3:9: error: invalid right operand: f64 += string
+    1 | fn main() {
+    2 |     mut foo := 1.5
+    3 |     foo += 'hello'
+      |            ~~~~~~~
+    4 |     _ = foo
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_i.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_i.vv
new file mode 100644
index 0000000..2debbae
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_type_err_i.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut foo := 1.5
+	foo += 'hello'
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_a.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_a.out
new file mode 100644
index 0000000..d7aaac0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_a.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_a.vv:2:7: error: undefined variable: `a`
+    1 | fn main() {
+    2 |     a := a
+      |          ^
+    3 |     println(a)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_a.vv
new file mode 100644
index 0000000..05ffdf4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_a.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a := a
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_b.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_b.out
new file mode 100644
index 0000000..f43a641
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_b.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_b.vv:2:10: error: undefined variable: `a`
+    1 | fn main() {
+    2 |     a, b := a, b
+      |             ^
+    3 |     println('$a, $b')
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_b.vv
new file mode 100644
index 0000000..b77ab6c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_b.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a, b := a, b
+	println('$a, $b')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_c.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_c.out
new file mode 100644
index 0000000..a68f329
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_c.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_c.vv:2:10: error: undefined variable: `a`
+    1 | fn main() {
+    2 |     a, b := a + 1, b * 3
+      |             ^
+    3 |     println('$a, $b')
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_c.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_c.vv
new file mode 100644
index 0000000..b845893
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_c.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a, b := a + 1, b * 3
+	println('$a, $b')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_d.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_d.out
new file mode 100644
index 0000000..4a8df88
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_d.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_d.vv:2:9: error: undefined variable: `s`
+    1 | fn main() {
+    2 |     s := '$s'
+      |            ^
+    3 |     println(s)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_d.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_d.vv
new file mode 100644
index 0000000..f9acc47
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_d.vv
@@ -0,0 +1,4 @@
+fn main() {
+	s := '$s'
+	println(s)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_e.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_e.out
new file mode 100644
index 0000000..e505e4c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_e.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_e.vv:2:11: error: undefined variable: `a`
+    1 | fn main() {
+    2 |     a, b := -a, -b
+      |              ^
+    3 |     println(s)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_e.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_e.vv
new file mode 100644
index 0000000..47e4ed5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_e.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a, b := -a, -b
+	println(s)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_f.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_f.out
new file mode 100644
index 0000000..1b1f926
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_f.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_f.vv:2:12: error: undefined variable: `a`
+    1 | fn main() {
+    2 |     a, b := (-a + 1), 1
+      |               ^
+    3 |     println('$a, $b')
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_f.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_f.vv
new file mode 100644
index 0000000..79ec348
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_f.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a, b := (-a + 1), 1
+	println('$a, $b')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_g.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_g.out
new file mode 100644
index 0000000..277bbaf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_g.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/assign_expr_undefined_err_g.vv:2:14: error: undefined variable: `file`
+    1 | fn main() {
+    2 |     mut file := file.open_file('bees.pdf', 'rw', 0o666)
+      |                 ~~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_g.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_g.vv
new file mode 100644
index 0000000..b589a78
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_g.vv
@@ -0,0 +1,3 @@
+fn main() {
+	mut file := file.open_file('bees.pdf', 'rw', 0o666)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_h.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_h.out
new file mode 100644
index 0000000..9c647c8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_h.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_expr_undefined_err_h.vv:6:9: error: undefined variable: `n`
+    4 | 
+    5 | fn main() {
+    6 |     n := f(n)
+      |            ^
+    7 |     println(n)
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_h.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_h.vv
new file mode 100644
index 0000000..d872d7e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_h.vv
@@ -0,0 +1,8 @@
+fn f(i int) int {
+	return i
+}
+
+fn main() {
+	n := f(n)
+	println(n)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_i.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_i.out
new file mode 100644
index 0000000..74705af
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_i.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_i.vv:2:23: error: undefined variable: `a`
+    1 | fn main() {
+    2 |     mut a := []int{init: a}
+      |                          ^
+    3 |     println(a)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_i.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_i.vv
new file mode 100644
index 0000000..26d689e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_i.vv
@@ -0,0 +1,4 @@
+fn main() {
+	mut a := []int{init: a}
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_j.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_j.out
new file mode 100644
index 0000000..5ca8f5a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_j.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_j.vv:2:12: error: undefined variable: `a`
+    1 | fn main() {
+    2 |     mut a := [a]
+      |               ^
+    3 |     println(a)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_j.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_j.vv
new file mode 100644
index 0000000..0406da7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_j.vv
@@ -0,0 +1,4 @@
+fn main() {
+	mut a := [a]
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_k.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_k.out
new file mode 100644
index 0000000..0dd8e1c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_k.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_expr_undefined_err_k.vv:2:22: error: undefined variable: `a`
+    1 | fn main() {
+    2 |     mut a := map{'one': a}
+      |                         ^
+    3 |     println(a)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_k.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_k.vv
new file mode 100644
index 0000000..e4d1e89
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_undefined_err_k.vv
@@ -0,0 +1,4 @@
+fn main() {
+	mut a := map{'one': a}
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_unresolved_variables_err_chain.out b/v_windows/v/old/vlib/v/checker/tests/assign_expr_unresolved_variables_err_chain.out
new file mode 100644
index 0000000..5c7e5cf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_unresolved_variables_err_chain.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/assign_expr_unresolved_variables_err_chain.vv:2:7: error: undefined variable `b` (used before declaration)
+    1 | fn main() {
+    2 |     a := b
+      |          ^
+    3 |     b := c
+    4 |     c := a
+vlib/v/checker/tests/assign_expr_unresolved_variables_err_chain.vv:3:7: error: undefined variable `c` (used before declaration)
+    1 | fn main() {
+    2 |     a := b
+    3 |     b := c
+      |          ^
+    4 |     c := a
+    5 |     _ = a
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_expr_unresolved_variables_err_chain.vv b/v_windows/v/old/vlib/v/checker/tests/assign_expr_unresolved_variables_err_chain.vv
new file mode 100644
index 0000000..279d6f5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_expr_unresolved_variables_err_chain.vv
@@ -0,0 +1,8 @@
+fn main() {
+	a := b
+	b := c
+	c := a
+	_ = a
+	_ = b
+	_ = c
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_fn_call_on_left_side_err.out b/v_windows/v/old/vlib/v/checker/tests/assign_fn_call_on_left_side_err.out
new file mode 100644
index 0000000..6a1a663
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_fn_call_on_left_side_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/assign_fn_call_on_left_side_err.vv:6:2: error: cannot call function `foo()` on the left side of an assignment
+    4 | 
+    5 | fn main() {
+    6 |     foo('s') = 1
+      |     ~~~~~~~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_fn_call_on_left_side_err.vv b/v_windows/v/old/vlib/v/checker/tests/assign_fn_call_on_left_side_err.vv
new file mode 100644
index 0000000..69c26dd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_fn_call_on_left_side_err.vv
@@ -0,0 +1,7 @@
+fn foo(s string) int {
+	return 1
+}
+
+fn main() {
+	foo('s') = 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_multi_immutable_err.out b/v_windows/v/old/vlib/v/checker/tests/assign_multi_immutable_err.out
new file mode 100644
index 0000000..635e020
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_multi_immutable_err.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/assign_multi_immutable_err.vv:4:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    2 |     a := 10
+    3 |     b := 20
+    4 |     a, b = 1, 2
+      |     ^
+    5 |
+    6 |     println('$a, $b')
+vlib/v/checker/tests/assign_multi_immutable_err.vv:18:5: error: cannot assign to function `error`
+   16 |
+   17 | fn assign_fn() {
+   18 |     _, error = g()
+      |        ~~~~~
+   19 |     g = f()
+   20 | }
+vlib/v/checker/tests/assign_multi_immutable_err.vv:19:2: error: cannot assign to function `g`
+   17 | fn assign_fn() {
+   18 |     _, error = g()
+   19 |     g = f()
+      |     ^
+   20 | }
+   21 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_multi_immutable_err.vv b/v_windows/v/old/vlib/v/checker/tests/assign_multi_immutable_err.vv
new file mode 100644
index 0000000..cfed449
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_multi_immutable_err.vv
@@ -0,0 +1,21 @@
+fn main() {
+	a := 10
+	b := 20
+	a, b = 1, 2
+
+	println('$a, $b')
+}
+
+fn f() int {
+	return 2
+}
+
+fn g() (int, int) {
+  return 1, 2
+}
+
+fn assign_fn() {
+	_, error = g()
+	g = f()
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_multi_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/assign_multi_mismatch.out
new file mode 100644
index 0000000..ded3db7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_multi_mismatch.out
@@ -0,0 +1,81 @@
+vlib/v/checker/tests/assign_multi_mismatch.vv:5:3: error: assignment mismatch: 1 variable(s) 2 value(s)
+    3 | }
+    4 | 
+    5 | _ := 0, 0
+      |   ~~
+    6 | _ := f()
+    7 | _, _ := f()
+vlib/v/checker/tests/assign_multi_mismatch.vv:6:3: error: assignment mismatch: 1 variable(s) but `f()` returns 2 value(s)
+    4 | 
+    5 | _ := 0, 0
+    6 | _ := f()
+      |   ~~
+    7 | _, _ := f()
+    8 | _, _ := 0, f()
+vlib/v/checker/tests/assign_multi_mismatch.vv:8:12: error: cannot use multi-value (int, int) in single-value context
+    6 | _ := f()
+    7 | _, _ := f()
+    8 | _, _ := 0, f()
+      |            ~~~
+    9 | _, _ := f(), 0
+   10 | _, _, _ := 0, f()
+vlib/v/checker/tests/assign_multi_mismatch.vv:9:9: error: cannot use multi-value (int, int) in single-value context
+    7 | _, _ := f()
+    8 | _, _ := 0, f()
+    9 | _, _ := f(), 0
+      |         ~~~
+   10 | _, _, _ := 0, f()
+   11 | _, _, _ := f(), 0
+vlib/v/checker/tests/assign_multi_mismatch.vv:10:15: error: cannot use multi-value (int, int) in single-value context
+    8 | _, _ := 0, f()
+    9 | _, _ := f(), 0
+   10 | _, _, _ := 0, f()
+      |               ~~~
+   11 | _, _, _ := f(), 0
+   12 | _, _ := f(), f()
+vlib/v/checker/tests/assign_multi_mismatch.vv:11:12: error: cannot use multi-value (int, int) in single-value context
+    9 | _, _ := f(), 0
+   10 | _, _, _ := 0, f()
+   11 | _, _, _ := f(), 0
+      |            ~~~
+   12 | _, _ := f(), f()
+   13 | _, _, _, _ := f(), f()
+vlib/v/checker/tests/assign_multi_mismatch.vv:12:9: error: cannot use multi-value (int, int) in single-value context
+   10 | _, _, _ := 0, f()
+   11 | _, _, _ := f(), 0
+   12 | _, _ := f(), f()
+      |         ~~~
+   13 | _, _, _, _ := f(), f()
+   14 |
+vlib/v/checker/tests/assign_multi_mismatch.vv:13:15: error: cannot use multi-value (int, int) in single-value context
+   11 | _, _, _ := f(), 0
+   12 | _, _ := f(), f()
+   13 | _, _, _, _ := f(), f()
+      |               ~~~
+   14 | 
+   15 | _, _ := 0, match 4 {
+vlib/v/checker/tests/assign_multi_mismatch.vv:19:3: error: assignment mismatch: 1 variable(s) 2 value(s)
+   17 |     else { 1 }
+   18 | }
+   19 | _ := match 4 {
+      |   ~~
+   20 |     1 { f() }
+   21 |     else { f() }
+vlib/v/checker/tests/assign_multi_mismatch.vv:23:12: error: cannot use multi-value (int, int) in single-value context
+   21 |     else { f() }
+   22 | }
+   23 | _, _ := 0, match 4 {
+      |            ~~~~~~~~~
+   24 |     1 { f() }
+   25 |     else { f() }
+vlib/v/checker/tests/assign_multi_mismatch.vv:29:3: error: assignment mismatch: 1 variable(s) 2 value(s)
+   27 | 
+   28 | _, _ := 0, if true { 0 } else { 1 }
+   29 | _ := if true { f() } else { f() }
+      |   ~~
+   30 | _, _ := 0, if true { f() } else { f() }
+vlib/v/checker/tests/assign_multi_mismatch.vv:30:12: error: cannot use multi-value (int, int) in single-value context
+   28 | _, _ := 0, if true { 0 } else { 1 }
+   29 | _ := if true { f() } else { f() }
+   30 | _, _ := 0, if true { f() } else { f() }
+      |            ~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_multi_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/assign_multi_mismatch.vv
new file mode 100644
index 0000000..d25815c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_multi_mismatch.vv
@@ -0,0 +1,30 @@
+fn f() (int, int) {
+	return 0, 0
+}
+
+_ := 0, 0
+_ := f()
+_, _ := f()
+_, _ := 0, f()
+_, _ := f(), 0
+_, _, _ := 0, f()
+_, _, _ := f(), 0
+_, _ := f(), f()
+_, _, _, _ := f(), f()
+
+_, _ := 0, match 4 {
+	1 { 0 }
+	else { 1 }
+}
+_ := match 4 {
+	1 { f() }
+	else { f() }
+}
+_, _ := 0, match 4 {
+	1 { f() }
+	else { f() }
+}
+
+_, _ := 0, if true { 0 } else { 1 }
+_ := if true { f() } else { f() }
+_, _ := 0, if true { f() } else { f() }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_mut.out b/v_windows/v/old/vlib/v/checker/tests/assign_mut.out
new file mode 100644
index 0000000..93a1d06
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_mut.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_mut.vv:3:11: error: expecting `:=` (e.g. `mut x :=`)
+    1 | fn main() {
+    2 |     mut z := 1
+    3 |     mut z = 1
+      |           ^
+    4 |     mut i := 2
+    5 |     i, mut z = 2,3
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_mut.vv b/v_windows/v/old/vlib/v/checker/tests/assign_mut.vv
new file mode 100644
index 0000000..be80643
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_mut.vv
@@ -0,0 +1,6 @@
+fn main() {
+    mut z := 1
+    mut z = 1
+    mut i := 2
+    i, mut z = 2,3
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_sumtype2_err.out b/v_windows/v/old/vlib/v/checker/tests/assign_sumtype2_err.out
new file mode 100644
index 0000000..9e1b60a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_sumtype2_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_sumtype2_err.vv:13:3: error: cannot assign to field `decl`: expected `Decl`, not `Stmt`
+   11 |     stmt := Stmt(Decl{})
+   12 |     _ := File{
+   13 |         decl: stmt
+      |         ~~~~~~~~~~
+   14 |     }
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_sumtype2_err.vv b/v_windows/v/old/vlib/v/checker/tests/assign_sumtype2_err.vv
new file mode 100644
index 0000000..29e36ce
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_sumtype2_err.vv
@@ -0,0 +1,15 @@
+type Stmt = Decl | Expr
+
+struct Decl {}
+struct Expr {}
+
+struct File {
+	decl Decl
+}
+
+fn main() {
+	stmt := Stmt(Decl{})
+	_ := File{
+		decl: stmt
+	}
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_sumtype_err.out b/v_windows/v/old/vlib/v/checker/tests/assign_sumtype_err.out
new file mode 100644
index 0000000..ebb4b7a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_sumtype_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/assign_sumtype_err.vv:13:9: error: cannot assign to `decl`: expected `Decl`, not `Stmt`
+   11 |     stmt := Stmt(Decl{})
+   12 |     mut decl := Decl{}
+   13 |     decl = stmt
+      |            ~~~~
+   14 |     _ = decl
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/assign_sumtype_err.vv b/v_windows/v/old/vlib/v/checker/tests/assign_sumtype_err.vv
new file mode 100644
index 0000000..94e6fa1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/assign_sumtype_err.vv
@@ -0,0 +1,15 @@
+type Stmt = Decl | Expr
+
+struct Decl {}
+struct Expr {}
+
+struct File {
+	decl Decl
+}
+
+fn main() {
+	stmt := Stmt(Decl{})
+	mut decl := Decl{}
+	decl = stmt
+	_ = decl
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/bad_types_in_string_inter_lit.out b/v_windows/v/old/vlib/v/checker/tests/bad_types_in_string_inter_lit.out
new file mode 100644
index 0000000..e6a1cac
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bad_types_in_string_inter_lit.out
@@ -0,0 +1,8 @@
+vlib/v/checker/tests/bad_types_in_string_inter_lit.vv:1:12: error: expression does not return a value
+    1 | println('${exit(0)}')
+      |            ~~~~~~~
+    2 | println('${char(48)}')
+vlib/v/checker/tests/bad_types_in_string_inter_lit.vv:2:12: error: expression returning type `char` cannot be used in string interpolation directly, print its address or cast it to an integer instead
+    1 | println('${exit(0)}')
+    2 | println('${char(48)}')
+      |            ~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/bad_types_in_string_inter_lit.vv b/v_windows/v/old/vlib/v/checker/tests/bad_types_in_string_inter_lit.vv
new file mode 100644
index 0000000..e4dc26c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bad_types_in_string_inter_lit.vv
@@ -0,0 +1,2 @@
+println('${exit(0)}')
+println('${char(48)}')
diff --git a/v_windows/v/old/vlib/v/checker/tests/bin_lit_without_digit_err.out b/v_windows/v/old/vlib/v/checker/tests/bin_lit_without_digit_err.out
new file mode 100644
index 0000000..772f15d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bin_lit_without_digit_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/bin_lit_without_digit_err.vv:2:14: error: number part of this binary is not provided
+    1 | fn main() {
+    2 |     println(0b**)
+      |              ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/bin_lit_without_digit_err.vv b/v_windows/v/old/vlib/v/checker/tests/bin_lit_without_digit_err.vv
new file mode 100644
index 0000000..a85579d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bin_lit_without_digit_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(0b**)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/bin_lit_wrong_digit_err.out b/v_windows/v/old/vlib/v/checker/tests/bin_lit_wrong_digit_err.out
new file mode 100644
index 0000000..e2f993a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bin_lit_wrong_digit_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/bin_lit_wrong_digit_err.vv:2:18: error: this binary number has unsuitable digit `2`
+    1 | fn main() {
+    2 |     println(0b1112)
+      |                  ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/bin_lit_wrong_digit_err.vv b/v_windows/v/old/vlib/v/checker/tests/bin_lit_wrong_digit_err.vv
new file mode 100644
index 0000000..b8347fa
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bin_lit_wrong_digit_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(0b1112)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_left_type_err.out b/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_left_type_err.out
new file mode 100644
index 0000000..e8d7a31
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_left_type_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/bit_op_wrong_left_type_err.vv:2:10: error: left type of `&` cannot be non-integer type `float literal`
+    1 | fn main() {
+    2 |     println(0.5 & 1)
+      |             ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_left_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_left_type_err.vv
new file mode 100644
index 0000000..60b0da5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_left_type_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	println(0.5 & 1)
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_right_type_err.out b/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_right_type_err.out
new file mode 100644
index 0000000..7b24344
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_right_type_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/bit_op_wrong_right_type_err.vv:2:14: error: right type of `|` cannot be non-integer type `float literal`
+    1 | fn main() {
+    2 |     println(1 | 0.5)
+      |                 ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_right_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_right_type_err.vv
new file mode 100644
index 0000000..d9da95c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bit_op_wrong_right_type_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	println(1 | 0.5)
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/blank_ident_invalid_use.out b/v_windows/v/old/vlib/v/checker/tests/blank_ident_invalid_use.out
new file mode 100644
index 0000000..9385664
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/blank_ident_invalid_use.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/blank_ident_invalid_use.vv:2:8: error: undefined ident: `_` (may only be used in assignments)
+    1 | fn main() {
+    2 |     _ := [_]
+      |           ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/blank_ident_invalid_use.vv b/v_windows/v/old/vlib/v/checker/tests/blank_ident_invalid_use.vv
new file mode 100644
index 0000000..4be90be
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/blank_ident_invalid_use.vv
@@ -0,0 +1,3 @@
+fn main() {
+	_ := [_]
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/blank_modify.out b/v_windows/v/old/vlib/v/checker/tests/blank_modify.out
new file mode 100644
index 0000000..e0d02e2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/blank_modify.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/blank_modify.vv:2:2: error: cannot modify blank `_` identifier
+    1 | fn main() {
+    2 |     _ += 1
+      |     ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/blank_modify.vv b/v_windows/v/old/vlib/v/checker/tests/blank_modify.vv
new file mode 100644
index 0000000..0a22021
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/blank_modify.vv
@@ -0,0 +1,3 @@
+fn main() {
+	_ += 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/bool_string_cast_err.out b/v_windows/v/old/vlib/v/checker/tests/bool_string_cast_err.out
new file mode 100644
index 0000000..44a1643
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bool_string_cast_err.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/bool_string_cast_err.vv:2:13: error: cannot cast type `bool` to string, use `x.str()` instead
+    1 | fn main() {
+    2 |     println(string(true))
+      |             ~~~~~~~~~~~~
+    3 |     println(string(false))
+    4 | }
+vlib/v/checker/tests/bool_string_cast_err.vv:3:13: error: cannot cast type `bool` to string, use `x.str()` instead
+    1 | fn main() {
+    2 |     println(string(true))
+    3 |     println(string(false))
+      |             ~~~~~~~~~~~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/bool_string_cast_err.vv b/v_windows/v/old/vlib/v/checker/tests/bool_string_cast_err.vv
new file mode 100644
index 0000000..c261155
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/bool_string_cast_err.vv
@@ -0,0 +1,4 @@
+fn main() {
+    println(string(true))
+    println(string(false))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/break_anon_fn_err.out b/v_windows/v/old/vlib/v/checker/tests/break_anon_fn_err.out
new file mode 100644
index 0000000..82b7ab5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/break_anon_fn_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/break_anon_fn_err.vv:4:4: error: break statement not within a loop
+    2 |     for true {
+    3 |         _ := fn () int {
+    4 |             break
+      |             ~~~~~
+    5 |             return 3
+    6 |         }()
diff --git a/v_windows/v/old/vlib/v/checker/tests/break_anon_fn_err.vv b/v_windows/v/old/vlib/v/checker/tests/break_anon_fn_err.vv
new file mode 100644
index 0000000..26586e6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/break_anon_fn_err.vv
@@ -0,0 +1,8 @@
+fn main() {
+	for true {
+		_ := fn () int {
+			break
+			return 3
+		}()
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/c_fn_surplus_args.out b/v_windows/v/old/vlib/v/checker/tests/c_fn_surplus_args.out
new file mode 100644
index 0000000..a462c84
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/c_fn_surplus_args.out
@@ -0,0 +1,42 @@
+vlib/v/checker/tests/c_fn_surplus_args.vv:6:7: error: expected 0 arguments, but got 1
+    4 | 
+    5 | fn main() {
+    6 |     C.no(1) // allowed
+      |          ^
+    7 |     C.y1()
+    8 |     C.y1(1) // ok
+vlib/v/checker/tests/c_fn_surplus_args.vv:7:4: error: expected 1 arguments, but got 0
+    5 | fn main() {
+    6 |     C.no(1) // allowed
+    7 |     C.y1()
+      |       ~~~~
+    8 |     C.y1(1) // ok
+    9 |     C.y1(1, 2)
+vlib/v/checker/tests/c_fn_surplus_args.vv:9:10: error: expected 1 arguments, but got 2
+    7 |     C.y1()
+    8 |     C.y1(1) // ok
+    9 |     C.y1(1, 2)
+      |             ^
+   10 |     C.ret() // ok
+   11 |     C.ret(1)
+vlib/v/checker/tests/c_fn_surplus_args.vv:11:8: error: expected 0 arguments, but got 1
+    9 |     C.y1(1, 2)
+   10 |     C.ret() // ok
+   11 |     C.ret(1)
+      |           ^
+   12 |     // avoid cgen whilst warning, later above should error
+   13 |     main()
+vlib/v/checker/tests/c_fn_surplus_args.vv:13:2: error: the `main` function cannot be called in the program
+   11 |     C.ret(1)
+   12 |     // avoid cgen whilst warning, later above should error
+   13 |     main()
+      |     ~~~~~~
+   14 |     C.af() // ok
+   15 |     C.af(3)
+vlib/v/checker/tests/c_fn_surplus_args.vv:15:7: error: expected 0 arguments, but got 1
+   13 |     main()
+   14 |     C.af() // ok
+   15 |     C.af(3)
+      |          ^
+   16 | }
+   17 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/c_fn_surplus_args.vv b/v_windows/v/old/vlib/v/checker/tests/c_fn_surplus_args.vv
new file mode 100644
index 0000000..e7c6466
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/c_fn_surplus_args.vv
@@ -0,0 +1,19 @@
+fn C.no() // untyped
+fn C.y1(int)
+fn C.ret()byte
+
+fn main() {
+	C.no(1) // allowed
+	C.y1()
+	C.y1(1) // ok
+	C.y1(1, 2)
+	C.ret() // ok
+	C.ret(1)
+	// avoid cgen whilst warning, later above should error
+	main()
+	C.af() // ok
+	C.af(3)
+}
+
+[trusted]
+fn C.af()int
diff --git a/v_windows/v/old/vlib/v/checker/tests/cannot_assign_array.out b/v_windows/v/old/vlib/v/checker/tests/cannot_assign_array.out
new file mode 100644
index 0000000..fc82be4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cannot_assign_array.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/cannot_assign_array.vv:9:11: error: cannot assign to `ctx.vb`: expected `string`, not `[8]f64`
+    7 |     mut ctx := Context{}
+    8 |     x := 2.32
+    9 |     ctx.vb = [1.1, x, 3.3, 4.4, 5.0, 6.0, 7.0, 8.9]!
+      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/cannot_assign_array.vv b/v_windows/v/old/vlib/v/checker/tests/cannot_assign_array.vv
new file mode 100644
index 0000000..d6aba2d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cannot_assign_array.vv
@@ -0,0 +1,10 @@
+struct Context {
+	pub mut:
+	vb string
+}
+
+fn main() {
+	mut ctx := Context{}
+	x := 2.32
+	ctx.vb = [1.1, x, 3.3, 4.4, 5.0, 6.0, 7.0, 8.9]!
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_alias.out b/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_alias.out
new file mode 100644
index 0000000..6a7960c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_alias.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/cannot_cast_to_alias.vv:6:7: error: cannot convert type `int literal` to `MyType` (alias to `string`)
+    4 |
+    5 | fn main() {
+    6 |     _ := MyType(5)
+      |          ~~~~~~~~~
+    7 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_alias.vv b/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_alias.vv
new file mode 100644
index 0000000..1198570
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_alias.vv
@@ -0,0 +1,7 @@
+module main
+
+type MyType = string
+
+fn main() {
+	_ := MyType(5)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_struct.out b/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_struct.out
new file mode 100644
index 0000000..9fe4c10
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_struct.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/cannot_cast_to_struct.vv:10:7: error: casting to struct is deprecated, use e.g. `Struct{...expr}` instead
+    8 | 
+    9 | fn main() {
+   10 |     _ := Test(Abc{})
+      |          ~~~~~~~~~~~
+   11 |     sum := Alphabet(Xyz{})
+   12 |     _ = Xyz(sum)
+vlib/v/checker/tests/cannot_cast_to_struct.vv:12:6: error: cannot cast `Alphabet` to struct
+   10 |     _ := Test(Abc{})
+   11 |     sum := Alphabet(Xyz{})
+   12 |     _ = Xyz(sum)
+      |         ~~~~~~~~
+   13 |     _ = Xyz(5)
+   14 |     s := Abc{}
+vlib/v/checker/tests/cannot_cast_to_struct.vv:13:6: error: cannot cast `int literal` to struct
+   11 |     sum := Alphabet(Xyz{})
+   12 |     _ = Xyz(sum)
+   13 |     _ = Xyz(5)
+      |         ~~~~~~
+   14 |     s := Abc{}
+   15 |     _ = Xyz(&s)
+vlib/v/checker/tests/cannot_cast_to_struct.vv:15:6: error: cannot cast `&Abc` to struct
+   13 |     _ = Xyz(5)
+   14 |     s := Abc{}
+   15 |     _ = Xyz(&s)
+      |         ~~~~~~~
+   16 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_struct.vv b/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_struct.vv
new file mode 100644
index 0000000..64cf7fa
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cannot_cast_to_struct.vv
@@ -0,0 +1,16 @@
+struct Abc {}
+struct Xyz {}
+type Alphabet = Abc | Xyz
+
+struct Test {
+	abc Alphabet
+}
+
+fn main() {
+	_ := Test(Abc{})
+	sum := Alphabet(Xyz{})
+	_ = Xyz(sum)
+	_ = Xyz(5)
+	s := Abc{}
+	_ = Xyz(&s)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/cast_err.out b/v_windows/v/old/vlib/v/checker/tests/cast_err.out
new file mode 100644
index 0000000..c78a99d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cast_err.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/cast_err.vv:3:6: error: cannot cast to bool - use e.g. `some_int != 0` instead
+    1 | fn test_bool_cast() {
+    2 |     v := 3
+    3 |     _ = bool(v)
+      |         ~~~~~~~
+    4 |     _ = bool(&v)
+    5 |     _ = bool([2])
+vlib/v/checker/tests/cast_err.vv:4:6: error: cannot cast to bool - use e.g. `some_int != 0` instead
+    2 |     v := 3
+    3 |     _ = bool(v)
+    4 |     _ = bool(&v)
+      |         ~~~~~~~~
+    5 |     _ = bool([2])
+    6 | }
+vlib/v/checker/tests/cast_err.vv:5:6: error: cannot cast to bool - use e.g. `some_int != 0` instead
+    3 |     _ = bool(v)
+    4 |     _ = bool(&v)
+    5 |     _ = bool([2])
+      |         ~~~~~~~~~
+    6 | }
+    7 |
+vlib/v/checker/tests/cast_err.vv:9:6: error: unknown type `Foo`
+    7 | 
+    8 | fn unknown() {
+    9 |     _ = Foo(3)
+      |         ~~~~~~
+   10 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/cast_err.vv b/v_windows/v/old/vlib/v/checker/tests/cast_err.vv
new file mode 100644
index 0000000..bcf8ad3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cast_err.vv
@@ -0,0 +1,10 @@
+fn test_bool_cast() {
+	v := 3
+	_ = bool(v)
+	_ = bool(&v)
+	_ = bool([2])
+}
+
+fn unknown() {
+	_ = Foo(3)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/cast_string_err.out b/v_windows/v/old/vlib/v/checker/tests/cast_string_err.out
new file mode 100644
index 0000000..3c09bf4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cast_string_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/cast_string_err.vv:2:7: error: cannot cast type `int literal` to string, use `x.str()` instead
+    1 | fn main() {
+    2 |     a := string(1)
+      |          ~~~~~~~~~
+    3 |     println(a)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/cast_string_err.vv b/v_windows/v/old/vlib/v/checker/tests/cast_string_err.vv
new file mode 100644
index 0000000..56247ce
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cast_string_err.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a := string(1)
+	println(a)
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/cast_string_with_byte_err.out b/v_windows/v/old/vlib/v/checker/tests/cast_string_with_byte_err.out
new file mode 100644
index 0000000..1b04218
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cast_string_with_byte_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/cast_string_with_byte_err.vv:2:12: error: can not cast type `byte` to string, use `by.str()` instead.
+    1 | for by in 'abc' {
+    2 |    println(string(by))
+      |            ~~~~~~~~~~
+    3 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/cast_string_with_byte_err.vv b/v_windows/v/old/vlib/v/checker/tests/cast_string_with_byte_err.vv
new file mode 100644
index 0000000..4626e28
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cast_string_with_byte_err.vv
@@ -0,0 +1,3 @@
+for by in 'abc' {
+   println(string(by))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/cast_void.out b/v_windows/v/old/vlib/v/checker/tests/cast_void.out
new file mode 100644
index 0000000..ddd389a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cast_void.out
@@ -0,0 +1,4 @@
+vlib/v/checker/tests/cast_void.vv:1:12: error: expression does not return a value so it cannot be cast
+    1 | num := int(print(''))
+      |            ~~~~~~~~~
+    2 | println(num)
diff --git a/v_windows/v/old/vlib/v/checker/tests/cast_void.vv b/v_windows/v/old/vlib/v/checker/tests/cast_void.vv
new file mode 100644
index 0000000..1b61f14
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/cast_void.vv
@@ -0,0 +1,2 @@
+num := int(print(''))
+println(num)
diff --git a/v_windows/v/old/vlib/v/checker/tests/chan_args.out b/v_windows/v/old/vlib/v/checker/tests/chan_args.out
new file mode 100644
index 0000000..605bcfe
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/chan_args.out
@@ -0,0 +1,28 @@
+vlib/v/checker/tests/chan_args.vv:4:19: error: cannot use `int` as `&f64` in argument 1 to `chan f64.try_push`
+    2 |     ch := chan f64{cap: 5}
+    3 |     a := 2
+    4 |     _ := ch.try_push(a)
+      |                      ^
+    5 |     _ := ch.try_push(2.5)
+    6 |     b := 2.5
+vlib/v/checker/tests/chan_args.vv:5:19: error: cannot use `float literal` as `&f64` in argument 1 to `chan f64.try_push`
+    3 |     a := 2
+    4 |     _ := ch.try_push(a)
+    5 |     _ := ch.try_push(2.5)
+      |                      ~~~
+    6 |     b := 2.5
+    7 |     _ := ch.try_pop(b)
+vlib/v/checker/tests/chan_args.vv:7:18: error: `try_pop` parameter `obj` is `mut`, you need to provide `mut` e.g. `mut arg1`
+    5 |     _ := ch.try_push(2.5)
+    6 |     b := 2.5
+    7 |     _ := ch.try_pop(b)
+      |                     ^
+    8 |     // this should work:
+    9 |     _ := ch.try_push(b)
+vlib/v/checker/tests/chan_args.vv:11:22: error: cannot use `int` as argument for `try_pop` (`f64` expected)
+    9 |     _ := ch.try_push(b)
+   10 |     mut c := 7
+   11 |     _ := ch.try_pop(mut c)
+      |                         ^
+   12 |     mut x := 12.5
+   13 |     // this should work:
diff --git a/v_windows/v/old/vlib/v/checker/tests/chan_args.vv b/v_windows/v/old/vlib/v/checker/tests/chan_args.vv
new file mode 100644
index 0000000..ce16cd8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/chan_args.vv
@@ -0,0 +1,15 @@
+fn main() {
+	ch := chan f64{cap: 5}
+	a := 2
+	_ := ch.try_push(a)
+	_ := ch.try_push(2.5)
+	b := 2.5
+	_ := ch.try_pop(b)
+	// this should work:
+	_ := ch.try_push(b)
+	mut c := 7
+	_ := ch.try_pop(mut c)
+	mut x := 12.5
+	// this should work:
+	_ := ch.try_pop(mut x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/chan_mut.out b/v_windows/v/old/vlib/v/checker/tests/chan_mut.out
new file mode 100644
index 0000000..e82419b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/chan_mut.out
@@ -0,0 +1,28 @@
+vlib/v/checker/tests/chan_mut.vv:8:8: error: `v` is immutable, declare it with `mut` to make it mutable
+    6 | fn f(ch chan mut St) {
+    7 |     v := St{}
+    8 |     ch <- v
+      |           ^
+    9 |     mut w := St{}
+   10 |     ch <- w
+vlib/v/checker/tests/chan_mut.vv:10:8: error: cannot push non-reference `St` on `chan mut St`
+    8 |     ch <- v
+    9 |     mut w := St{}
+   10 |     ch <- w
+      |           ^
+   11 |     x := &St{}
+   12 |     ch <- x
+vlib/v/checker/tests/chan_mut.vv:12:8: error: `x` is immutable, declare it with `mut` to make it mutable
+   10 |     ch <- w
+   11 |     x := &St{}
+   12 |     ch <- x
+      |           ^
+   13 |     mut y := St{}
+   14 |     ch <- y
+vlib/v/checker/tests/chan_mut.vv:14:8: error: cannot push non-reference `St` on `chan mut St`
+   12 |     ch <- x
+   13 |     mut y := St{}
+   14 |     ch <- y
+      |           ^
+   15 |     mut z := &St{n: 7}
+   16 |     // this works
diff --git a/v_windows/v/old/vlib/v/checker/tests/chan_mut.vv b/v_windows/v/old/vlib/v/checker/tests/chan_mut.vv
new file mode 100644
index 0000000..1250c51
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/chan_mut.vv
@@ -0,0 +1,27 @@
+struct St{
+mut:
+	n int
+}
+
+fn f(ch chan mut St) {
+	v := St{}
+	ch <- v
+	mut w := St{}
+	ch <- w
+	x := &St{}
+	ch <- x
+	mut y := St{}
+	ch <- y
+	mut z := &St{n: 7}
+	// this works
+	ch <- z
+}
+
+fn main() {
+	c := chan mut St{}
+	go f(c)
+	mut y := <-c
+	z := <-c
+	println(y)
+	println(z)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/chan_ref.out b/v_windows/v/old/vlib/v/checker/tests/chan_ref.out
new file mode 100644
index 0000000..3eeb76b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/chan_ref.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/chan_ref.vv:10:8: error: cannot push non-reference `St` on `chan &St`
+    8 | fn f(ch chan &St, mut sem sync.Semaphore) {
+    9 |     w := St{}
+   10 |     ch <- w
+      |           ^
+   11 |     mut x := St{}
+   12 |     ch <- x
+vlib/v/checker/tests/chan_ref.vv:12:8: error: cannot push non-reference `St` on `chan &St`
+   10 |     ch <- w
+   11 |     mut x := St{}
+   12 |     ch <- x
+      |           ^
+   13 |     // the following works
+   14 |     y := &St{}
diff --git a/v_windows/v/old/vlib/v/checker/tests/chan_ref.vv b/v_windows/v/old/vlib/v/checker/tests/chan_ref.vv
new file mode 100644
index 0000000..ad3dcec
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/chan_ref.vv
@@ -0,0 +1,33 @@
+import sync
+
+struct St{
+mut:
+	n int
+}
+
+fn f(ch chan &St, mut sem sync.Semaphore) {
+	w := St{}
+	ch <- w
+	mut x := St{}
+	ch <- x
+	// the following works
+	y := &St{}
+	ch <- y
+	mut z := &St{}
+	ch <- z
+	sem.wait()
+	println(z)
+}
+
+fn main() {
+	c := chan &St{}
+	mut sem := sync.new_semaphore()
+	go f(c, mut sem)
+	y := <-c
+	// this should fail
+	mut z := <-c
+	z.n = 9
+	sem.post()
+	println(y)
+	println(z)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/char_str.out b/v_windows/v/old/vlib/v/checker/tests/char_str.out
new file mode 100644
index 0000000..9779e64
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/char_str.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/char_str.vv:1:1: error: calling `.str()` on type `char` is not allowed, use its address or cast it to an integer instead
+    1 | char(91).str()
+      | ~~~~~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/char_str.vv b/v_windows/v/old/vlib/v/checker/tests/char_str.vv
new file mode 100644
index 0000000..88d9a9b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/char_str.vv
@@ -0,0 +1 @@
+char(91).str()
diff --git a/v_windows/v/old/vlib/v/checker/tests/comparing_typesymbol_to_a_type_should_not_compile.out b/v_windows/v/old/vlib/v/checker/tests/comparing_typesymbol_to_a_type_should_not_compile.out
new file mode 100644
index 0000000..3b8aae9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comparing_typesymbol_to_a_type_should_not_compile.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/comparing_typesymbol_to_a_type_should_not_compile.vv:12:7: error: possible type mismatch of compared values of `==` operation
+   10 |     x := ityp == ast.string_type
+   11 |     // the next line should produce at least a warning, or even an error, without an explicit cast:
+   12 |     z := isym == ast.string_type
+      |          ~~~~~~~~~~~~~~~~~~~~~~~
+   13 |     println(typeof(isym).name)
+   14 |     println(typeof(ast.string_type).name)
diff --git a/v_windows/v/old/vlib/v/checker/tests/comparing_typesymbol_to_a_type_should_not_compile.vv b/v_windows/v/old/vlib/v/checker/tests/comparing_typesymbol_to_a_type_should_not_compile.vv
new file mode 100644
index 0000000..6a307d3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comparing_typesymbol_to_a_type_should_not_compile.vv
@@ -0,0 +1,17 @@
+import v.ast
+
+fn main() {
+	t := ast.new_table()
+	ityp := ast.int_type
+	isym := t.get_type_symbol(ityp)
+	println(ityp.debug())
+	println(isym)
+	println(isym.debug())
+	x := ityp == ast.string_type
+	// the next line should produce at least a warning, or even an error, without an explicit cast:
+	z := isym == ast.string_type
+	println(typeof(isym).name)
+	println(typeof(ast.string_type).name)
+	println(x)
+	println(z)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_call_method.out b/v_windows/v/old/vlib/v/checker/tests/comptime_call_method.out
new file mode 100644
index 0000000..de71203
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_call_method.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/comptime_call_method.vv:10:14: error: undefined ident: `wrong`
+    8 |     s1 := S1{}
+    9 |     $for method in S1.methods {
+   10 |         s1.$method(wrong)
+      |                    ~~~~~
+   11 |     }
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_call_method.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_call_method.vv
new file mode 100644
index 0000000..2c21789
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_call_method.vv
@@ -0,0 +1,12 @@
+struct S1 {}
+
+fn (t S1) m(s string) int {
+	return 7
+}
+
+fn test_methods_arg() {
+	s1 := S1{}
+	$for method in S1.methods {
+		s1.$method(wrong)
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_call_no_unused_var.out b/v_windows/v/old/vlib/v/checker/tests/comptime_call_no_unused_var.out
new file mode 100644
index 0000000..17aae7c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_call_no_unused_var.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/comptime_call_no_unused_var.vv:11:8: error: unknown identifier `w`
+    9 |     abc := 'print'
+   10 |     test.$abc() // OK
+   11 |     test.$w()
+      |           ^
+   12 |     v := 4
+   13 |     test.$v()
+vlib/v/checker/tests/comptime_call_no_unused_var.vv:13:8: error: invalid string method call: expected `string`, not `int`
+   11 |     test.$w()
+   12 |     v := 4
+   13 |     test.$v()
+      |           ^
+   14 |     s := 'x' + 'y'
+   15 |     test.$s()
+vlib/v/checker/tests/comptime_call_no_unused_var.vv:15:8: error: todo: not a string literal
+   13 |     test.$v()
+   14 |     s := 'x' + 'y'
+   15 |     test.$s()
+      |           ^
+   16 |     s2 := 'x'
+   17 |     test.$s2()
+vlib/v/checker/tests/comptime_call_no_unused_var.vv:17:8: error: could not find method `x`
+   15 |     test.$s()
+   16 |     s2 := 'x'
+   17 |     test.$s2()
+      |           ~~
+   18 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_call_no_unused_var.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_call_no_unused_var.vv
new file mode 100644
index 0000000..b38c031
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_call_no_unused_var.vv
@@ -0,0 +1,18 @@
+struct Test {}
+
+fn (test Test) print() {
+	println('test')
+}
+
+fn main() {
+	test := Test{}
+	abc := 'print'
+	test.$abc() // OK
+	test.$w()
+	v := 4
+	test.$v()
+	s := 'x' + 'y'
+	test.$s()
+	s2 := 'x'
+	test.$s2()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_1.run.out b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_1.run.out
new file mode 100644
index 0000000..098d716
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_1.run.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/comptime_env/env_parser_errors_1.vv:1:1: error: supply an env variable name like HOME, PATH or USER
+    1 | #flag -I $env('')/xyz
+      | ~~~~~~~~~~~~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_1.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_1.vv
new file mode 100644
index 0000000..83b2ff3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_1.vv
@@ -0,0 +1 @@
+#flag -I $env('')/xyz
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_2.run.out b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_2.run.out
new file mode 100644
index 0000000..0cc6a11
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_2.run.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/comptime_env/env_parser_errors_2.vv:1:1: error: cannot use string interpolation in compile time $env() expression
+    1 | #flag -I $env('$ABC')/xyz
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_2.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_2.vv
new file mode 100644
index 0000000..abd0b76
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_2.vv
@@ -0,0 +1 @@
+#flag -I $env('$ABC')/xyz
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_3.run.out b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_3.run.out
new file mode 100644
index 0000000..eab0231
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_3.run.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/comptime_env/env_parser_errors_3.vv:1:1: error: no "$env('...')" could be found in "-I $env()/xyz".
+    1 | #flag -I $env()/xyz
+      | ~~~~~~~~~~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_3.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_3.vv
new file mode 100644
index 0000000..98fc6fe
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/env_parser_errors_3.vv
@@ -0,0 +1 @@
+#flag -I $env()/xyz
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.run.out b/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.run.out
new file mode 100644
index 0000000..962652a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.run.out
@@ -0,0 +1,11 @@
+vlib/v/checker/tests/comptime_env/using_comptime_env.vv:1:1: error: the environment variable "VAR" does not exist.
+    1 | #flag -I $env('VAR')/xyz
+      | ~~~~~~~~~~~~~~~~~~~~~~~~
+    2 | #include "$env('VAR')/stdio.h"
+    3 |
+vlib/v/checker/tests/comptime_env/using_comptime_env.vv:2:1: error: the environment variable "VAR" does not exist.
+    1 | #flag -I $env('VAR')/xyz
+    2 | #include "$env('VAR')/stdio.h"
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    3 | 
+    4 | fn main() {
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.var.run.out b/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.var.run.out
new file mode 100644
index 0000000..012aa03
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.var.run.out
@@ -0,0 +1,2 @@
+/usr/include
+done
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.var_invalid.run.out b/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.var_invalid.run.out
new file mode 100644
index 0000000..0739bb2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.var_invalid.run.out
@@ -0,0 +1 @@
+builder error: '/opt/invalid/path/stdio.h' not found
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.vv
new file mode 100644
index 0000000..f49508c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_env/using_comptime_env.vv
@@ -0,0 +1,8 @@
+#flag -I $env('VAR')/xyz
+#include "$env('VAR')/stdio.h"
+
+fn main() {
+	env := $env('VAR')
+	println(env)
+	println('done')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_in_for_err.out b/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_in_for_err.out
new file mode 100644
index 0000000..bc3e1f9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_in_for_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/comptime_field_selector_not_in_for_err.vv:9:6: error: expected selector expression e.g. `$(field.name)`
+    7 |     mut t := T{}
+    8 |     name := 'test'
+    9 |     t.$(name) = '3'
+      |         ~~~~
+   10 | }
+   11 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_in_for_err.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_in_for_err.vv
new file mode 100644
index 0000000..bbbf854
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_in_for_err.vv
@@ -0,0 +1,14 @@
+struct Foo {
+	test int
+	name string
+}
+
+fn test<T>() {
+	mut t := T{}
+	name := 'test'
+	t.$(name) = '3'
+}
+
+fn main() {
+	test<Foo>()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_name_err.out b/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_name_err.out
new file mode 100644
index 0000000..c53955c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_name_err.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/comptime_field_selector_not_name_err.vv:10:8: error: expected `string` instead of `FieldData` (e.g. `field.name`)
+    8 |     $for f in T.fields {
+    9 |         $if f.typ is string {
+   10 |             t.$(f) = '3'
+      |                 ^
+   11 |             fv := Foo{}
+   12 |             _ = t.$(fv.name)
+vlib/v/checker/tests/comptime_field_selector_not_name_err.vv:12:12: error: unknown `$for` variable `fv`
+   10 |             t.$(f) = '3'
+   11 |             fv := Foo{}
+   12 |             _ = t.$(fv.name)
+      |                     ~~
+   13 |         }
+   14 |     }
+vlib/v/checker/tests/comptime_field_selector_not_name_err.vv:15:10: error: undefined ident: `f`
+   13 |         }
+   14 |     }
+   15 |     _ = t.$(f.name)
+      |             ^
+   16 | }
+   17 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_name_err.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_name_err.vv
new file mode 100644
index 0000000..9efd144
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_field_selector_not_name_err.vv
@@ -0,0 +1,20 @@
+struct Foo {
+	test int
+	name string
+}
+
+fn test<T>() {
+	mut t := T{}
+	$for f in T.fields {
+		$if f.typ is string {
+			t.$(f) = '3'
+			fv := Foo{}
+			_ = t.$(fv.name)
+		}
+	}
+	_ = t.$(f.name)
+}
+
+fn main() {
+	test<Foo>()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_for.out b/v_windows/v/old/vlib/v/checker/tests/comptime_for.out
new file mode 100644
index 0000000..0eea091
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_for.out
@@ -0,0 +1,55 @@
+vlib/v/checker/tests/comptime_for.vv:2:12: error: unknown type `Huh`
+    1 | fn unknown() {
+    2 |     $for m in Huh.methods {}
+      |               ~~~
+    3 |     $for f in Huh.fields {}
+    4 |     $for f in T.fields {
+vlib/v/checker/tests/comptime_for.vv:3:12: error: unknown type `Huh`
+    1 | fn unknown() {
+    2 |     $for m in Huh.methods {}
+    3 |     $for f in Huh.fields {}
+      |               ~~~
+    4 |     $for f in T.fields {
+    5 |         $if f.typ is Huh {}
+vlib/v/checker/tests/comptime_for.vv:4:12: error: unknown type `T`
+    2 |     $for m in Huh.methods {}
+    3 |     $for f in Huh.fields {}
+    4 |     $for f in T.fields {
+      |               ^
+    5 |         $if f.typ is Huh {}
+    6 |         $if f.typ is T {}
+vlib/v/checker/tests/comptime_for.vv:5:16: error: unknown type `Huh`
+    3 |     $for f in Huh.fields {}
+    4 |     $for f in T.fields {
+    5 |         $if f.typ is Huh {}
+      |                      ~~~
+    6 |         $if f.typ is T {}
+    7 |     }
+vlib/v/checker/tests/comptime_for.vv:6:16: error: unknown type `T`
+    4 |     $for f in T.fields {
+    5 |         $if f.typ is Huh {}
+    6 |         $if f.typ is T {}
+      |                      ^
+    7 |     }
+    8 |     _ = m
+vlib/v/checker/tests/comptime_for.vv:8:6: error: undefined ident: `m`
+    6 |         $if f.typ is T {}
+    7 |     }
+    8 |     _ = m
+      |         ^
+    9 | }
+   10 |
+vlib/v/checker/tests/comptime_for.vv:14:16: error: unknown type `U`
+   12 |     $for f in T.fields {
+   13 |         $if f.typ is T {}
+   14 |         $if f.typ is U {}
+      |                      ^
+   15 |     }
+   16 |     _ = f
+vlib/v/checker/tests/comptime_for.vv:16:6: error: undefined ident: `f`
+   14 |         $if f.typ is U {}
+   15 |     }
+   16 |     _ = f
+      |         ^
+   17 | }
+   18 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/comptime_for.vv b/v_windows/v/old/vlib/v/checker/tests/comptime_for.vv
new file mode 100644
index 0000000..a6d67a0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/comptime_for.vv
@@ -0,0 +1,23 @@
+fn unknown() {
+	$for m in Huh.methods {}
+	$for f in Huh.fields {}
+	$for f in T.fields {
+		$if f.typ is Huh {}
+		$if f.typ is T {}
+	}
+	_ = m
+}
+
+fn gf<T>() {
+	$for f in T.fields {
+		$if f.typ is T {}
+		$if f.typ is U {}
+	}
+	_ = f
+}
+
+struct S1 {
+	i int
+}
+
+gf<S1>()
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_array_unknown_type_err.out b/v_windows/v/old/vlib/v/checker/tests/const_array_unknown_type_err.out
new file mode 100644
index 0000000..8b55d3f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_array_unknown_type_err.out
@@ -0,0 +1,4 @@
+vlib/v/checker/tests/const_array_unknown_type_err.vv:1:11: error: unknown type `BB`.
+Did you mean `AA`?
+    1 | type AA = [20]BB
+      |           ~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_array_unknown_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/const_array_unknown_type_err.vv
new file mode 100644
index 0000000..88a2bf7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_array_unknown_type_err.vv
@@ -0,0 +1 @@
+type AA = [20]BB
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_define_in_function_err.out b/v_windows/v/old/vlib/v/checker/tests/const_define_in_function_err.out
new file mode 100644
index 0000000..e3b3544
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_define_in_function_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/const_define_in_function_err.vv:2:2: error: const can only be defined at the top level (outside of functions)
+    1 | fn main() {
+    2 |     const (a = 1)
+      |     ~~~~~
+    3 |     println(a)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_define_in_function_err.vv b/v_windows/v/old/vlib/v/checker/tests/const_define_in_function_err.vv
new file mode 100644
index 0000000..e6da548
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_define_in_function_err.vv
@@ -0,0 +1,4 @@
+fn main() {
+	const (a = 1)
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_add_err.out b/v_windows/v/old/vlib/v/checker/tests/const_field_add_err.out
new file mode 100644
index 0000000..1250582
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_add_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/const_field_add_err.vv:6:2: error: cannot modify constant `a`
+    4 | 
+    5 | fn main() {
+    6 |     a += 1
+      |     ^
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_add_err.vv b/v_windows/v/old/vlib/v/checker/tests/const_field_add_err.vv
new file mode 100644
index 0000000..24a6bb5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_add_err.vv
@@ -0,0 +1,7 @@
+const (
+	a = 1
+)
+
+fn main() {
+	a += 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_dec_err.out b/v_windows/v/old/vlib/v/checker/tests/const_field_dec_err.out
new file mode 100644
index 0000000..e0b9acb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_dec_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/const_field_dec_err.vv:6:2: error: cannot modify constant `a`
+    4 | 
+    5 | fn main() {
+    6 |     a--
+      |     ^
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_dec_err.vv b/v_windows/v/old/vlib/v/checker/tests/const_field_dec_err.vv
new file mode 100644
index 0000000..0f99839
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_dec_err.vv
@@ -0,0 +1,7 @@
+const (
+	a = 1
+)
+
+fn main() {
+	a--
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_inc_err.out b/v_windows/v/old/vlib/v/checker/tests/const_field_inc_err.out
new file mode 100644
index 0000000..adeee60
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_inc_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/const_field_inc_err.vv:6:2: error: cannot modify constant `a` 
+    4 | 
+    5 | fn main() {
+    6 |     a++
+      |     ^
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_inc_err.vv b/v_windows/v/old/vlib/v/checker/tests/const_field_inc_err.vv
new file mode 100644
index 0000000..9d0d96e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_inc_err.vv
@@ -0,0 +1,7 @@
+const (
+	a = 1
+)
+
+fn main() {
+	a++
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_name_duplicate_err.out b/v_windows/v/old/vlib/v/checker/tests/const_field_name_duplicate_err.out
new file mode 100644
index 0000000..e887c13
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_name_duplicate_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/const_field_name_duplicate_err.vv:3:2: error: duplicate const `aaa`
+    1 | const (
+    2 |     aaa = 1
+    3 |     aaa = 2
+      |     ~~~
+    4 | )
+    5 | fn main() {
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_name_duplicate_err.vv b/v_windows/v/old/vlib/v/checker/tests/const_field_name_duplicate_err.vv
new file mode 100644
index 0000000..f489f51
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_name_duplicate_err.vv
@@ -0,0 +1,7 @@
+const (
+	aaa = 1
+	aaa = 2
+)
+fn main() {
+	println(aaa)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_name_snake_case.out b/v_windows/v/old/vlib/v/checker/tests/const_field_name_snake_case.out
new file mode 100644
index 0000000..ff997e4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_name_snake_case.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/const_field_name_snake_case.vv:2:2: warning: const names cannot contain uppercase letters, use snake_case instead
+    1 | const (
+    2 |     Red = 1
+      |     ~~~
+    3 | )
+    4 | fn main() { println(Red) }
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_name_snake_case.vv b/v_windows/v/old/vlib/v/checker/tests/const_field_name_snake_case.vv
new file mode 100644
index 0000000..cd8af8e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_name_snake_case.vv
@@ -0,0 +1,4 @@
+const (
+	Red = 1
+)
+fn main() { println(Red) }
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_sub_err.out b/v_windows/v/old/vlib/v/checker/tests/const_field_sub_err.out
new file mode 100644
index 0000000..782520b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_sub_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/const_field_sub_err.vv:6:2: error: cannot modify constant `a`
+    4 | 
+    5 | fn main() {
+    6 |     a -= 1
+      |     ^
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/const_field_sub_err.vv b/v_windows/v/old/vlib/v/checker/tests/const_field_sub_err.vv
new file mode 100644
index 0000000..e6c021b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/const_field_sub_err.vv
@@ -0,0 +1,7 @@
+const (
+	a = 1
+)
+
+fn main() {
+	a -= 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/ctdefine.out b/v_windows/v/old/vlib/v/checker/tests/ctdefine.out
new file mode 100644
index 0000000..008a7d6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ctdefine.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/ctdefine.vv:4:1: error: only functions that do NOT return values can have `[if test]` tags
+    2 |
+    3 | [if test]
+    4 | fn only_called_in_test() string {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    5 |     return 'bah'
+    6 | }
+vlib/v/checker/tests/ctdefine.vv:1:1: error: project must include a `main` module or be a shared library (compile with `v -shared`)
+    1 | module notmain
+      | ^
+    2 |
+    3 | [if test]
diff --git a/v_windows/v/old/vlib/v/checker/tests/ctdefine.vv b/v_windows/v/old/vlib/v/checker/tests/ctdefine.vv
new file mode 100644
index 0000000..20d1eb0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ctdefine.vv
@@ -0,0 +1,6 @@
+module notmain
+
+[if test]
+fn only_called_in_test() string {
+	return 'bah'
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.mysymbol.run.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.mysymbol.run.out
new file mode 100644
index 0000000..97a3e70
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.mysymbol.run.out
@@ -0,0 +1,2 @@
+optional compitme define works
+non optional comptime define works
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.out
new file mode 100644
index 0000000..b916d1d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/custom_comptime_define_error.vv:6:13: error: undefined ident: `mysymbol`
+    4 |             println('optional compitme define works')
+    5 |         }
+    6 |         $if mysymbol {
+      |             ~~~~~~~~
+    7 |             // this will produce a checker error when `-d mysymbol` is not given on the CLI
+    8 |             println('non optional comptime define works')
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.vv b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.vv
new file mode 100644
index 0000000..34f9967
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_error.vv
@@ -0,0 +1,10 @@
+fn main() {
+        $if mysymbol? {
+			// this should not produce checker errors, but will print only with `-d mysymbol`
+			println('optional compitme define works')
+        }
+        $if mysymbol {
+			// this will produce a checker error when `-d mysymbol` is not given on the CLI
+            println('non optional comptime define works')
+        }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.cg.run.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.cg.run.out
new file mode 100644
index 0000000..b8cdbba
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.cg.run.out
@@ -0,0 +1,3 @@
+main with debug
+foo, x: 123
+done
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.debug.bar.run.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.debug.bar.run.out
new file mode 100644
index 0000000..702459b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.debug.bar.run.out
@@ -0,0 +1,3 @@
+foo, x: 123
+bar, x: 456
+done
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.debug.run.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.debug.run.out
new file mode 100644
index 0000000..8cdd401
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.debug.run.out
@@ -0,0 +1,2 @@
+foo, x: 123
+done
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.g.run.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.g.run.out
new file mode 100644
index 0000000..b8cdbba
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.g.run.out
@@ -0,0 +1,3 @@
+main with debug
+foo, x: 123
+done
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.run.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.run.out
new file mode 100644
index 0000000..19f86f4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.run.out
@@ -0,0 +1 @@
+done
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.vv b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.vv
new file mode 100644
index 0000000..380f738
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_debug.vv
@@ -0,0 +1,18 @@
+[if debug]
+fn foo(x int) {
+	println('foo, x: $x')
+}
+
+[if bar ?]
+fn bar(x int) {
+	println('bar, x: $x')
+}
+
+fn main() {
+	$if debug {
+		println('main with debug')
+	}
+	foo(123) // will not be called if `-d debug` is not passed
+	bar(456) // will not be called if `-d bar` is not passed
+	println('done')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.mydebug.run.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.mydebug.run.out
new file mode 100644
index 0000000..7cf4d92
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.mydebug.run.out
@@ -0,0 +1,4 @@
+start
+message: verbose message
+message: debugging system
+end
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.nodebug.run.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.nodebug.run.out
new file mode 100644
index 0000000..5d0fb3b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.nodebug.run.out
@@ -0,0 +1,2 @@
+start
+end
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.out b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.vv b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.vv
new file mode 100644
index 0000000..23e946a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/custom_comptime_define_if_flag.vv
@@ -0,0 +1,13 @@
+// Calls to edebug/1 should be executed only when `-d mydebug` is passed on the CLI
+// Otherwise they will not be present *at all* in the generated code.
+[if mydebug ?]
+fn edebug(message string) {
+	println('message: $message')
+}
+
+fn main() {
+	println('start')
+	edebug('verbose message')
+	edebug('debugging system')
+	println('end')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/dec_lit_wrong_digit_err.out b/v_windows/v/old/vlib/v/checker/tests/dec_lit_wrong_digit_err.out
new file mode 100644
index 0000000..9166f4c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/dec_lit_wrong_digit_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/dec_lit_wrong_digit_err.vv:2:18: error: this number has unsuitable digit `q`
+    1 | fn main() {
+    2 |     println(12345qrst+10)
+      |                  ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/dec_lit_wrong_digit_err.vv b/v_windows/v/old/vlib/v/checker/tests/dec_lit_wrong_digit_err.vv
new file mode 100644
index 0000000..c8c9583
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/dec_lit_wrong_digit_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(12345qrst+10)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/decompose_type_err.out b/v_windows/v/old/vlib/v/checker/tests/decompose_type_err.out
new file mode 100644
index 0000000..95d56f6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/decompose_type_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/decompose_type_err.vv:4:13: error: decomposition can only be used on arrays
+    2 |
+    3 | fn main() {
+    4 |     varargs(...123)
+      |                ~~~
+    5 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/decompose_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/decompose_type_err.vv
new file mode 100644
index 0000000..d5b43ba
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/decompose_type_err.vv
@@ -0,0 +1,5 @@
+fn varargs(a ...int) { println(a) }
+
+fn main() {
+	varargs(...123)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/defer_in_for.out b/v_windows/v/old/vlib/v/checker/tests/defer_in_for.out
new file mode 100644
index 0000000..59faded
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/defer_in_for.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/defer_in_for.vv:4:13: error: `break` is not allowed in defer statements
+    2 |     for true {
+    3 |         defer {
+    4 |             break
+      |             ~~~~~
+    5 |         }
+    6 |     }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/defer_in_for.vv b/v_windows/v/old/vlib/v/checker/tests/defer_in_for.vv
new file mode 100644
index 0000000..bb2525f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/defer_in_for.vv
@@ -0,0 +1,7 @@
+fn main() {
+    for true {
+        defer {
+            break
+        }
+    }
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/defer_optional.out b/v_windows/v/old/vlib/v/checker/tests/defer_optional.out
new file mode 100644
index 0000000..184e35e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/defer_optional.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/defer_optional.vv:5:3: error: opt() returns an option, so it should have an `or {}` block at the end
+    3 | fn thing() ?string {
+    4 |     defer {
+    5 |         opt()
+      |         ~~~~~
+    6 |     }
+    7 |     return 'ok'
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/defer_optional.vv b/v_windows/v/old/vlib/v/checker/tests/defer_optional.vv
new file mode 100644
index 0000000..f153430
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/defer_optional.vv
@@ -0,0 +1,8 @@
+fn opt() ? {}
+
+fn thing() ?string {
+	defer {
+		opt()
+	}
+	return 'ok'
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/deprecations.out b/v_windows/v/old/vlib/v/checker/tests/deprecations.out
new file mode 100644
index 0000000..55b205f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/deprecations.out
@@ -0,0 +1,48 @@
+vlib/v/checker/tests/deprecations.vv:54:2: notice: function `future` will be deprecated after 9999-12-30; custom message 4
+   52 | 
+   53 | fn main() {
+   54 |     future()
+      |     ~~~~~~~~
+   55 |     past()
+   56 |     simply_deprecated()
+vlib/v/checker/tests/deprecations.vv:60:4: notice: method `Abc.future` will be deprecated after 9999-11-01; custom message 1
+   58 |     //
+   59 |     a := Abc{}
+   60 |     a.future()
+      |       ~~~~~~~~
+   61 |     a.past()
+   62 |     a.simply_deprecated()
+vlib/v/checker/tests/deprecations.vv:55:2: error: function `past` has been deprecated since 2021-03-01; custom message 5
+   53 | fn main() {
+   54 |     future()
+   55 |     past()
+      |     ~~~~~~
+   56 |     simply_deprecated()
+   57 |     just_deprecated()
+vlib/v/checker/tests/deprecations.vv:56:2: error: function `simply_deprecated` has been deprecated; custom message 6
+   54 |     future()
+   55 |     past()
+   56 |     simply_deprecated()
+      |     ~~~~~~~~~~~~~~~~~~~
+   57 |     just_deprecated()
+   58 |     //
+vlib/v/checker/tests/deprecations.vv:57:2: error: function `just_deprecated` has been deprecated
+   55 |     past()
+   56 |     simply_deprecated()
+   57 |     just_deprecated()
+      |     ~~~~~~~~~~~~~~~~~
+   58 |     //
+   59 |     a := Abc{}
+vlib/v/checker/tests/deprecations.vv:61:4: error: method `Abc.past` has been deprecated since 2021-03-01; custom message 2
+   59 |     a := Abc{}
+   60 |     a.future()
+   61 |     a.past()
+      |       ~~~~~~
+   62 |     a.simply_deprecated()
+   63 | }
+vlib/v/checker/tests/deprecations.vv:62:4: error: method `Abc.simply_deprecated` has been deprecated; custom message 3
+   60 |     a.future()
+   61 |     a.past()
+   62 |     a.simply_deprecated()
+      |       ~~~~~~~~~~~~~~~~~~~
+   63 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/deprecations.vv b/v_windows/v/old/vlib/v/checker/tests/deprecations.vv
new file mode 100644
index 0000000..4a731ce
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/deprecations.vv
@@ -0,0 +1,63 @@
+// methods using [deprecated_after]:
+struct Abc {
+	x int
+}
+
+fn (a Abc) str() string {
+	return 'Abc { x: $a.x }'
+}
+
+[deprecated: 'custom message 1']
+[deprecated_after: '9999-11-01']
+fn (a Abc) future() {
+	dump(@METHOD)
+	dump(a)
+}
+
+[deprecated: 'custom message 2']
+[deprecated_after: '2021-03-01']
+fn (a Abc) past() {
+	dump(@METHOD)
+	dump(a)
+}
+
+[deprecated: 'custom message 3']
+fn (a Abc) simply_deprecated() {
+	dump(@METHOD)
+	dump(a)
+}
+
+// functions using [deprecated_after]:
+[deprecated: 'custom message 4']
+[deprecated_after: '9999-12-30']
+fn future() {
+	dump(@FN)
+}
+
+[deprecated: 'custom message 5']
+[deprecated_after: '2021-03-01']
+fn past() {
+	dump(@FN)
+}
+
+[deprecated: 'custom message 6']
+fn simply_deprecated() {
+	dump(@FN)
+}
+
+[deprecated]
+fn just_deprecated() {
+	dump(@FN)
+}
+
+fn main() {
+	future()
+	past()
+	simply_deprecated()
+	just_deprecated()
+	//
+	a := Abc{}
+	a.future()
+	a.past()
+	a.simply_deprecated()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/direct_map_alias_init_err.out b/v_windows/v/old/vlib/v/checker/tests/direct_map_alias_init_err.out
new file mode 100644
index 0000000..d198c66
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/direct_map_alias_init_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/direct_map_alias_init_err.vv:4:7: error: direct map alias init is not possible, use `WordSet(map[string]bool{})` instead
+    2 |
+    3 | fn main() {
+    4 |     _ := WordSet{}
+      |          ~~~~~~~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/direct_map_alias_init_err.vv b/v_windows/v/old/vlib/v/checker/tests/direct_map_alias_init_err.vv
new file mode 100644
index 0000000..5921f5b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/direct_map_alias_init_err.vv
@@ -0,0 +1,5 @@
+type WordSet = map[string]bool
+
+fn main() {
+	_ := WordSet{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/disallow_pointer_arithmetic_err.out b/v_windows/v/old/vlib/v/checker/tests/disallow_pointer_arithmetic_err.out
new file mode 100644
index 0000000..3e4422f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/disallow_pointer_arithmetic_err.out
@@ -0,0 +1,34 @@
+vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:4:7: error: invalid operator `+` to `&int` and `&int`
+    2 |     x := 5
+    3 |     p := &x
+    4 |     _ := p + p //should be error
+      |          ~~~~~
+    5 |     _ := p * p //should be error
+    6 |     _ := p * 2 //should be error
+vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:5:7: error: invalid operator `*` to `&int` and `&int`
+    3 |     p := &x
+    4 |     _ := p + p //should be error
+    5 |     _ := p * p //should be error
+      |          ~~~~~
+    6 |     _ := p * 2 //should be error
+    7 |     _ := p + 5 //OK but only in unsafe block, r is *int
+vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:6:7: error: invalid operator `*` to `&int` and `int literal`
+    4 |     _ := p + p //should be error
+    5 |     _ := p * p //should be error
+    6 |     _ := p * 2 //should be error
+      |          ~~~~~
+    7 |     _ := p + 5 //OK but only in unsafe block, r is *int
+    8 |     _ := p - p //OK even in safe code, but n should be isize
+vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:7:7: error: pointer arithmetic is only allowed in `unsafe` blocks
+    5 |     _ := p * p //should be error
+    6 |     _ := p * 2 //should be error
+    7 |     _ := p + 5 //OK but only in unsafe block, r is *int
+      |          ~~~~~
+    8 |     _ := p - p //OK even in safe code, but n should be isize
+    9 | }
+vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:8:7: error: pointer arithmetic is only allowed in `unsafe` blocks
+    6 |     _ := p * 2 //should be error
+    7 |     _ := p + 5 //OK but only in unsafe block, r is *int
+    8 |     _ := p - p //OK even in safe code, but n should be isize
+      |          ~~~~~
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv b/v_windows/v/old/vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv
new file mode 100644
index 0000000..0fc91cd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv
@@ -0,0 +1,9 @@
+fn main() {
+	x := 5
+	p := &x
+	_ := p + p //should be error
+	_ := p * p //should be error
+	_ := p * 2 //should be error
+	_ := p + 5 //OK but only in unsafe block, r is *int
+	_ := p - p //OK even in safe code, but n should be isize
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/div_mod_by_cast_zero_int_err.out b/v_windows/v/old/vlib/v/checker/tests/div_mod_by_cast_zero_int_err.out
new file mode 100644
index 0000000..b29d963
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/div_mod_by_cast_zero_int_err.out
@@ -0,0 +1,40 @@
+vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv:2:21: error: division by zero
+    1 | fn main() {
+    2 |     println(u64(1)/u64(0))
+      |                        ^
+    3 |     println(u64(1)%u64(0))
+    4 |
+vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv:3:21: error: modulo by zero
+    1 | fn main() {
+    2 |     println(u64(1)/u64(0))
+    3 |     println(u64(1)%u64(0))
+      |                        ^
+    4 |
+    5 |     println(u32(1)/u32(0x0))
+vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv:5:21: error: division by zero
+    3 |     println(u64(1)%u64(0))
+    4 |
+    5 |     println(u32(1)/u32(0x0))
+      |                        ~~~
+    6 |     println(u32(1)%u32(0x0))
+    7 |
+vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv:6:21: error: modulo by zero
+    4 |
+    5 |     println(u32(1)/u32(0x0))
+    6 |     println(u32(1)%u32(0x0))
+      |                        ~~~
+    7 |
+    8 |     println(u16(1)/u16(0b0))
+vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv:8:21: error: division by zero
+    6 |     println(u32(1)%u32(0x0))
+    7 |
+    8 |     println(u16(1)/u16(0b0))
+      |                        ~~~
+    9 |     println(u16(1)%u16(0b0))
+   10 | }
+vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv:9:21: error: modulo by zero
+    7 |
+    8 |     println(u16(1)/u16(0b0))
+    9 |     println(u16(1)%u16(0b0))
+      |                        ~~~
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv b/v_windows/v/old/vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv
new file mode 100644
index 0000000..215ae9e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/div_mod_by_cast_zero_int_err.vv
@@ -0,0 +1,10 @@
+fn main() {
+	println(u64(1)/u64(0))
+	println(u64(1)%u64(0))
+
+	println(u32(1)/u32(0x0))
+	println(u32(1)%u32(0x0))
+
+	println(u16(1)/u16(0b0))
+	println(u16(1)%u16(0b0))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/div_op_wrong_type_err.out b/v_windows/v/old/vlib/v/checker/tests/div_op_wrong_type_err.out
new file mode 100644
index 0000000..f79c286
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/div_op_wrong_type_err.out
@@ -0,0 +1,42 @@
+vlib/v/checker/tests/div_op_wrong_type_err.vv:3:13: error: mismatched types `Aaa` and `int literal`
+    1 | struct Aaa{}
+    2 | fn main() {
+    3 |     println(Aaa{} / 10)
+      |             ~~~~~~~~~~
+    4 |     println(10 / Aaa{})
+    5 |     println([1,2,3] / 10)
+vlib/v/checker/tests/div_op_wrong_type_err.vv:4:13: error: mismatched types `int literal` and `Aaa`
+    2 | fn main() {
+    3 |     println(Aaa{} / 10)
+    4 |     println(10 / Aaa{})
+      |             ~~~~~~~~~~
+    5 |     println([1,2,3] / 10)
+    6 |     println(10 / [1,2,3])
+vlib/v/checker/tests/div_op_wrong_type_err.vv:5:13: error: mismatched types `[]int` and `int literal`
+    3 |     println(Aaa{} / 10)
+    4 |     println(10 / Aaa{})
+    5 |     println([1,2,3] / 10)
+      |             ~~~~~~~~~~~~
+    6 |     println(10 / [1,2,3])
+    7 |     a := map[string]int
+vlib/v/checker/tests/div_op_wrong_type_err.vv:6:13: error: mismatched types `int literal` and `[]int`
+    4 |     println(10 / Aaa{})
+    5 |     println([1,2,3] / 10)
+    6 |     println(10 / [1,2,3])
+      |             ~~~~~~~~~~~~
+    7 |     a := map[string]int
+    8 |     println(a / 10)
+vlib/v/checker/tests/div_op_wrong_type_err.vv:8:13: error: mismatched types `map[string]int` and `int literal`
+    6 |     println(10 / [1,2,3])
+    7 |     a := map[string]int
+    8 |     println(a / 10)
+      |             ~~~~~~
+    9 |     println(10 / a)
+   10 | }
+vlib/v/checker/tests/div_op_wrong_type_err.vv:9:13: error: mismatched types `int literal` and `map[string]int`
+    7 |     a := map[string]int
+    8 |     println(a / 10)
+    9 |     println(10 / a)
+      |             ~~~~~~
+   10 | }
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/div_op_wrong_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/div_op_wrong_type_err.vv
new file mode 100644
index 0000000..fb2f1cd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/div_op_wrong_type_err.vv
@@ -0,0 +1,10 @@
+struct Aaa{}
+fn main() {
+    println(Aaa{} / 10)
+    println(10 / Aaa{})
+    println([1,2,3] / 10)
+    println(10 / [1,2,3])
+	a := map[string]int
+    println(a / 10)
+    println(10 / a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/division_by_cast_zero_float_err.out b/v_windows/v/old/vlib/v/checker/tests/division_by_cast_zero_float_err.out
new file mode 100644
index 0000000..f6bbda2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/division_by_cast_zero_float_err.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/division_by_cast_zero_float_err.vv:2:23: error: division by zero
+    1 | fn main() {
+    2 |     println(f32(1.0)/f32(0.0))
+      |                          ~~~
+    3 |     println(f64(1.0)/f64(0.0))
+    4 | }
+vlib/v/checker/tests/division_by_cast_zero_float_err.vv:3:23: error: division by zero
+    1 | fn main() {
+    2 |     println(f32(1.0)/f32(0.0))
+    3 |     println(f64(1.0)/f64(0.0))
+      |                          ~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/division_by_cast_zero_float_err.vv b/v_windows/v/old/vlib/v/checker/tests/division_by_cast_zero_float_err.vv
new file mode 100644
index 0000000..6feee15
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/division_by_cast_zero_float_err.vv
@@ -0,0 +1,4 @@
+fn main() {
+	println(f32(1.0)/f32(0.0))
+	println(f64(1.0)/f64(0.0))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/division_by_zero_float_err.out b/v_windows/v/old/vlib/v/checker/tests/division_by_zero_float_err.out
new file mode 100644
index 0000000..7a2ee8d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/division_by_zero_float_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/division_by_zero_float_err.vv:2:14: error: division by zero
+    1 | fn main() {
+    2 |     println(1.0/0.0)
+      |                 ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/division_by_zero_float_err.vv b/v_windows/v/old/vlib/v/checker/tests/division_by_zero_float_err.vv
new file mode 100644
index 0000000..b5c1e7c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/division_by_zero_float_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	println(1.0/0.0)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/division_by_zero_int_err.out b/v_windows/v/old/vlib/v/checker/tests/division_by_zero_int_err.out
new file mode 100644
index 0000000..6b2ed19
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/division_by_zero_int_err.out
@@ -0,0 +1,26 @@
+vlib/v/checker/tests/division_by_zero_int_err.vv:2:12: error: division by zero
+    1 | fn main() {
+    2 |     println(1/0)
+      |               ^
+    3 |     println(1/0x0)
+    4 |     println(1/0b0)
+vlib/v/checker/tests/division_by_zero_int_err.vv:3:12: error: division by zero
+    1 | fn main() {
+    2 |     println(1/0)
+    3 |     println(1/0x0)
+      |               ~~~
+    4 |     println(1/0b0)
+    5 |     println(1/0o0)
+vlib/v/checker/tests/division_by_zero_int_err.vv:4:12: error: division by zero
+    2 |     println(1/0)
+    3 |     println(1/0x0)
+    4 |     println(1/0b0)
+      |               ~~~
+    5 |     println(1/0o0)
+    6 | }
+vlib/v/checker/tests/division_by_zero_int_err.vv:5:12: error: division by zero
+    3 |     println(1/0x0)
+    4 |     println(1/0b0)
+    5 |     println(1/0o0)
+      |               ~~~
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/division_by_zero_int_err.vv b/v_windows/v/old/vlib/v/checker/tests/division_by_zero_int_err.vv
new file mode 100644
index 0000000..4316fda
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/division_by_zero_int_err.vv
@@ -0,0 +1,6 @@
+fn main() {
+	println(1/0)
+	println(1/0x0)
+	println(1/0b0)
+	println(1/0o0)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/dump_of_void_expr.out b/v_windows/v/old/vlib/v/checker/tests/dump_of_void_expr.out
new file mode 100644
index 0000000..ac6f1b5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/dump_of_void_expr.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/dump_of_void_expr.vv:3:6: error: dump expression can not be void
+    1 | fn abc() {}
+    2 | 
+    3 | dump(abc())
+      |      ~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/dump_of_void_expr.vv b/v_windows/v/old/vlib/v/checker/tests/dump_of_void_expr.vv
new file mode 100644
index 0000000..57e8597
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/dump_of_void_expr.vv
@@ -0,0 +1,3 @@
+fn abc() {}
+
+dump(abc())
diff --git a/v_windows/v/old/vlib/v/checker/tests/duplicate_field_method_err.out b/v_windows/v/old/vlib/v/checker/tests/duplicate_field_method_err.out
new file mode 100644
index 0000000..b4befdd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/duplicate_field_method_err.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/duplicate_field_method_err.vv:5:1: error: type `St` has both field and method named `attr`
+    3 | }
+    4 | 
+    5 | fn (s St) attr() {}
+      | ~~~~~~~~~~~~~~~~
+    6 | 
+    7 | interface Foo {
+vlib/v/checker/tests/duplicate_field_method_err.vv:9:2: error: type `Foo` has both field and method named `bar`
+    7 | interface Foo {
+    8 |     bar fn ()
+    9 |     bar()
+      |     ~~~~~
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/duplicate_field_method_err.vv b/v_windows/v/old/vlib/v/checker/tests/duplicate_field_method_err.vv
new file mode 100644
index 0000000..2c34f78
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/duplicate_field_method_err.vv
@@ -0,0 +1,10 @@
+struct St{
+	attr fn()
+}
+
+fn (s St) attr() {}
+
+interface Foo {
+	bar fn ()
+	bar()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_as_int_err.out b/v_windows/v/old/vlib/v/checker/tests/enum_as_int_err.out
new file mode 100644
index 0000000..cef283d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_as_int_err.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/enum_as_int_err.vv:9:10: error: cannot assign to `color`: expected `Color`, not `int literal`
+    7 |     mut color := Color.red
+    8 |     mut foo := 1
+    9 |     color = 1
+      |             ^
+   10 |     foo = Color.red
+   11 |     println(color == 0)
+vlib/v/checker/tests/enum_as_int_err.vv:10:8: error: cannot assign to `foo`: expected `int`, not `Color`
+    8 |     mut foo := 1
+    9 |     color = 1
+   10 |     foo = Color.red
+      |           ~~~~~~~~~
+   11 |     println(color == 0)
+   12 |     _ = foo
+vlib/v/checker/tests/enum_as_int_err.vv:11:10: error: infix expr: cannot use `int literal` (right expression) as `Color`
+    9 |     color = 1
+   10 |     foo = Color.red
+   11 |     println(color == 0)
+      |             ~~~~~~~~~~
+   12 |     _ = foo
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_as_int_err.vv b/v_windows/v/old/vlib/v/checker/tests/enum_as_int_err.vv
new file mode 100644
index 0000000..47605ae
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_as_int_err.vv
@@ -0,0 +1,13 @@
+enum Color {
+	red
+	blue
+}
+
+fn main() {
+	mut color := Color.red
+	mut foo := 1
+	color = 1
+	foo = Color.red
+	println(color == 0)
+	_ = foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_cast.out b/v_windows/v/old/vlib/v/checker/tests/enum_cast.out
new file mode 100644
index 0000000..053fe1b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_cast.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/enum_cast.vv:6:13: error: 12 does not represents a value of enum Color
+    4 |     println(Color(0))
+    5 |     println(Color(10))
+    6 |     println(Color(12))
+      |             ~~~~~~~~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_cast.vv b/v_windows/v/old/vlib/v/checker/tests/enum_cast.vv
new file mode 100644
index 0000000..40e9ec7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_cast.vv
@@ -0,0 +1,7 @@
+enum Color { red green = 10 blue }
+
+fn main() {
+    println(Color(0))
+    println(Color(10))
+    println(Color(12))
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_empty.out b/v_windows/v/old/vlib/v/checker/tests/enum_empty.out
new file mode 100644
index 0000000..b2b432d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_empty.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/enum_empty.vv:1:1: error: enum cannot be empty
+    1 | enum Empty {}
+      | ~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_empty.vv b/v_windows/v/old/vlib/v/checker/tests/enum_empty.vv
new file mode 100644
index 0000000..7afdbc0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_empty.vv
@@ -0,0 +1 @@
+enum Empty {}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_err.out b/v_windows/v/old/vlib/v/checker/tests/enum_err.out
new file mode 100644
index 0000000..9256d7f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/enum_err.vv:4:13: error: default value for enum has to be an integer
+    2 |
+    3 | enum Color {
+    4 |     green = 'green'
+      |             ~~~~~~~
+    5 |     yellow = 1+1
+    6 |     blue
+vlib/v/checker/tests/enum_err.vv:5:14: error: default value for enum has to be an integer
+    3 | enum Color {
+    4 |     green = 'green'
+    5 |     yellow = 1+1
+      |              ~~~
+    6 |     blue
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_err.vv b/v_windows/v/old/vlib/v/checker/tests/enum_err.vv
new file mode 100644
index 0000000..1710b84
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_err.vv
@@ -0,0 +1,11 @@
+module main
+
+enum Color {
+    green = 'green'
+    yellow = 1+1
+    blue
+}
+
+fn main(){
+	println('hello')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_name_duplicate_err.out b/v_windows/v/old/vlib/v/checker/tests/enum_field_name_duplicate_err.out
new file mode 100644
index 0000000..6f1de8d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_name_duplicate_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/enum_field_name_duplicate_err.vv:5:2: error: field name `green` duplicate
+    3 |     yellow
+    4 |     blue
+    5 |     green
+      |     ~~~~~
+    6 | }
+    7 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_name_duplicate_err.vv b/v_windows/v/old/vlib/v/checker/tests/enum_field_name_duplicate_err.vv
new file mode 100644
index 0000000..790d39d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_name_duplicate_err.vv
@@ -0,0 +1,10 @@
+enum Color {
+    green
+    yellow
+    blue
+	green
+}
+
+fn main(){
+	println('hello')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_overflow.out b/v_windows/v/old/vlib/v/checker/tests/enum_field_overflow.out
new file mode 100644
index 0000000..26f5843
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_overflow.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/enum_field_overflow.vv:4:2: error: enum value overflows
+    2 |     red
+    3 |     green = 2147483647
+    4 |     blue
+      |     ~~~~
+    5 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_overflow.vv b/v_windows/v/old/vlib/v/checker/tests/enum_field_overflow.vv
new file mode 100644
index 0000000..8c79d29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_overflow.vv
@@ -0,0 +1,5 @@
+enum Color {
+	red
+	green = 2147483647
+	blue
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_a.out b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_a.out
new file mode 100644
index 0000000..ce72e69
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_a.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/enum_field_value_duplicate_a.vv:3:10: error: enum value `0` already exists
+    1 | enum Color {
+    2 |     red
+    3 |     green = 0
+      |             ^
+    4 |     blue  = 1
+    5 |     alpha = 1
+vlib/v/checker/tests/enum_field_value_duplicate_a.vv:5:10: error: enum value `1` already exists
+    3 |     green = 0
+    4 |     blue  = 1
+    5 |     alpha = 1
+      |             ^
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_a.vv b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_a.vv
new file mode 100644
index 0000000..49cf3c2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_a.vv
@@ -0,0 +1,6 @@
+enum Color {
+	red
+	green = 0
+	blue  = 1
+	alpha = 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_b.out b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_b.out
new file mode 100644
index 0000000..c1a9ae2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_b.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/enum_field_value_duplicate_b.vv:4:2: error: enum value `0` already exists
+    2 |     red // 0
+    3 |     green = -1
+    4 |     blue // -1 + 1 = 0
+      |     ~~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_b.vv b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_b.vv
new file mode 100644
index 0000000..232a265
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_duplicate_b.vv
@@ -0,0 +1,5 @@
+enum Color {
+	red // 0
+	green = -1
+	blue // -1 + 1 = 0
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_value_overflow.out b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_overflow.out
new file mode 100644
index 0000000..c6bb9c0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_overflow.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/enum_field_value_overflow.vv:3:10: error: enum value `2147483648` overflows int
+    1 | enum Color {
+    2 |     red
+    3 |     green = 2147483648
+      |             ~~~~~~~~~~
+    4 |     blue
+    5 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_field_value_overflow.vv b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_overflow.vv
new file mode 100644
index 0000000..cb9fb9a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_field_value_overflow.vv
@@ -0,0 +1,5 @@
+enum Color {
+	red
+	green = 2147483648
+	blue
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_op_err.out b/v_windows/v/old/vlib/v/checker/tests/enum_op_err.out
new file mode 100644
index 0000000..1392251
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_op_err.out
@@ -0,0 +1,34 @@
+vlib/v/checker/tests/enum_op_err.vv:8:20: error: only `==` and `!=` are defined on `enum`, use an explicit cast to `int` if needed
+    6 |
+    7 | fn main() {
+    8 |     println(Color.red > Color.green)
+      |                       ^
+    9 |     println(Color.red + Color.green)
+   10 |     println(Color.red && Color.green)
+vlib/v/checker/tests/enum_op_err.vv:9:20: error: only `==` and `!=` are defined on `enum`, use an explicit cast to `int` if needed
+    7 | fn main() {
+    8 |     println(Color.red > Color.green)
+    9 |     println(Color.red + Color.green)
+      |                       ^
+   10 |     println(Color.red && Color.green)
+   11 |     println(Color.red | Color.green)
+vlib/v/checker/tests/enum_op_err.vv:10:10: error: left operand for `&&` is not a boolean
+    8 |     println(Color.red > Color.green)
+    9 |     println(Color.red + Color.green)
+   10 |     println(Color.red && Color.green)
+      |             ~~~~~~~~~
+   11 |     println(Color.red | Color.green)
+   12 |     println(Color.red & Color.green)
+vlib/v/checker/tests/enum_op_err.vv:11:20: error: only `==` and `!=` are defined on `enum`, use an explicit cast to `int` if needed
+    9 |     println(Color.red + Color.green)
+   10 |     println(Color.red && Color.green)
+   11 |     println(Color.red | Color.green)
+      |                       ^
+   12 |     println(Color.red & Color.green)
+   13 | }
+vlib/v/checker/tests/enum_op_err.vv:12:20: error: only `==` and `!=` are defined on `enum`, use an explicit cast to `int` if needed
+   10 |     println(Color.red && Color.green)
+   11 |     println(Color.red | Color.green)
+   12 |     println(Color.red & Color.green)
+      |                       ^
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_op_err.vv b/v_windows/v/old/vlib/v/checker/tests/enum_op_err.vv
new file mode 100644
index 0000000..7fa48e4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_op_err.vv
@@ -0,0 +1,13 @@
+enum Color {
+	red
+	blue
+	green
+}
+
+fn main() {
+	println(Color.red > Color.green)
+	println(Color.red + Color.green)
+	println(Color.red && Color.green)
+	println(Color.red | Color.green)
+	println(Color.red & Color.green)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_op_flag_err.out b/v_windows/v/old/vlib/v/checker/tests/enum_op_flag_err.out
new file mode 100644
index 0000000..fb3e228
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_op_flag_err.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/enum_op_flag_err.vv:9:24: error: only `==`, `!=`, `|` and `&` are defined on `[flag]` tagged `enum`, use an explicit cast to `int` if needed
+    7 |
+    8 | fn main() {
+    9 |     println(FilePerm.read > FilePerm.write)
+      |                           ^
+   10 |     println(FilePerm.write + FilePerm.exec)
+   11 |     println(FilePerm.write && FilePerm.exec)
+vlib/v/checker/tests/enum_op_flag_err.vv:10:25: error: only `==`, `!=`, `|` and `&` are defined on `[flag]` tagged `enum`, use an explicit cast to `int` if needed
+    8 | fn main() {
+    9 |     println(FilePerm.read > FilePerm.write)
+   10 |     println(FilePerm.write + FilePerm.exec)
+      |                            ^
+   11 |     println(FilePerm.write && FilePerm.exec)
+   12 | }
+vlib/v/checker/tests/enum_op_flag_err.vv:11:10: error: left operand for `&&` is not a boolean
+    9 |     println(FilePerm.read > FilePerm.write)
+   10 |     println(FilePerm.write + FilePerm.exec)
+   11 |     println(FilePerm.write && FilePerm.exec)
+      |             ~~~~~~~~~~~~~~
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_op_flag_err.vv b/v_windows/v/old/vlib/v/checker/tests/enum_op_flag_err.vv
new file mode 100644
index 0000000..0701255
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_op_flag_err.vv
@@ -0,0 +1,12 @@
+[flag]
+enum FilePerm {
+	read
+	write
+	exec
+}
+
+fn main() {
+	println(FilePerm.read > FilePerm.write)
+	println(FilePerm.write + FilePerm.exec)
+	println(FilePerm.write && FilePerm.exec)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_single_letter.out b/v_windows/v/old/vlib/v/checker/tests/enum_single_letter.out
new file mode 100644
index 0000000..b509c5e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_single_letter.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/enum_single_letter.vv:1:6: error: single letter capital names are reserved for generic template types.
+    1 | enum E {
+      |      ^
+    2 |     v w
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/enum_single_letter.vv b/v_windows/v/old/vlib/v/checker/tests/enum_single_letter.vv
new file mode 100644
index 0000000..ef7bc65
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/enum_single_letter.vv
@@ -0,0 +1,4 @@
+enum E {
+    v w
+}
+println(E.v)
diff --git a/v_windows/v/old/vlib/v/checker/tests/eq_ne_op_wrong_type_err.out b/v_windows/v/old/vlib/v/checker/tests/eq_ne_op_wrong_type_err.out
new file mode 100644
index 0000000..d5f43cf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/eq_ne_op_wrong_type_err.out
@@ -0,0 +1,139 @@
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:12:10: error: infix expr: cannot use `int literal` (right expression) as `Aaa`
+   10 | 
+   11 | fn main() {
+   12 |     println(Aaa{} == 10)
+      |             ~~~~~~~~~~~
+   13 |     println(10 == Aaa{})
+   14 |     println(Aaa{} != 10)
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:13:10: error: infix expr: cannot use `Aaa` (right expression) as `int literal`
+   11 | fn main() {
+   12 |     println(Aaa{} == 10)
+   13 |     println(10 == Aaa{})
+      |             ~~~~~~~~~~~
+   14 |     println(Aaa{} != 10)
+   15 |     println(10 != Aaa{})
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:14:10: error: infix expr: cannot use `int literal` (right expression) as `Aaa`
+   12 |     println(Aaa{} == 10)
+   13 |     println(10 == Aaa{})
+   14 |     println(Aaa{} != 10)
+      |             ~~~~~~~~~~~
+   15 |     println(10 != Aaa{})
+   16 |
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:15:10: error: infix expr: cannot use `Aaa` (right expression) as `int literal`
+   13 |     println(10 == Aaa{})
+   14 |     println(Aaa{} != 10)
+   15 |     println(10 != Aaa{})
+      |             ~~~~~~~~~~~
+   16 | 
+   17 |     println(Aaa{0} == AAaa{0})
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:17:10: error: possible type mismatch of compared values of `==` operation
+   15 |     println(10 != Aaa{})
+   16 | 
+   17 |     println(Aaa{0} == AAaa{0})
+      |             ~~~~~~~~~~~~~~~~~
+   18 |     println(AAaa{0} == Aaa{0})
+   19 |     println(AAaa{1} != Aaa{1})
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:18:10: error: possible type mismatch of compared values of `==` operation
+   16 | 
+   17 |     println(Aaa{0} == AAaa{0})
+   18 |     println(AAaa{0} == Aaa{0})
+      |             ~~~~~~~~~~~~~~~~~
+   19 |     println(AAaa{1} != Aaa{1})
+   20 |     println(Aaa{1} != AAaa{1})
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:19:10: error: possible type mismatch of compared values of `!=` operation
+   17 |     println(Aaa{0} == AAaa{0})
+   18 |     println(AAaa{0} == Aaa{0})
+   19 |     println(AAaa{1} != Aaa{1})
+      |             ~~~~~~~~~~~~~~~~~
+   20 |     println(Aaa{1} != AAaa{1})
+   21 |
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:20:10: error: possible type mismatch of compared values of `!=` operation
+   18 |     println(AAaa{0} == Aaa{0})
+   19 |     println(AAaa{1} != Aaa{1})
+   20 |     println(Aaa{1} != AAaa{1})
+      |             ~~~~~~~~~~~~~~~~~
+   21 | 
+   22 |     arr := Arr([0])
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:23:10: error: possible type mismatch of compared values of `==` operation
+   21 | 
+   22 |     arr := Arr([0])
+   23 |     println(arr == [0])
+      |             ~~~~~~~~~~
+   24 |     println([1] == arr)
+   25 |     println(arr != [0])
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:24:10: error: possible type mismatch of compared values of `==` operation
+   22 |     arr := Arr([0])
+   23 |     println(arr == [0])
+   24 |     println([1] == arr)
+      |             ~~~~~~~~~~
+   25 |     println(arr != [0])
+   26 |     println([1] != arr)
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:25:10: error: possible type mismatch of compared values of `!=` operation
+   23 |     println(arr == [0])
+   24 |     println([1] == arr)
+   25 |     println(arr != [0])
+      |             ~~~~~~~~~~
+   26 |     println([1] != arr)
+   27 |
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:26:10: error: possible type mismatch of compared values of `!=` operation
+   24 |     println([1] == arr)
+   25 |     println(arr != [0])
+   26 |     println([1] != arr)
+      |             ~~~~~~~~~~
+   27 | 
+   28 |     arr_aaa := ArrAaa(arr)
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:29:10: error: possible type mismatch of compared values of `==` operation
+   27 | 
+   28 |     arr_aaa := ArrAaa(arr)
+   29 |     println(arr_aaa == arr)
+      |             ~~~~~~~~~~~~~~
+   30 |     println(arr == arr_aaa)
+   31 |     println(arr_aaa != arr)
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:30:10: error: possible type mismatch of compared values of `==` operation
+   28 |     arr_aaa := ArrAaa(arr)
+   29 |     println(arr_aaa == arr)
+   30 |     println(arr == arr_aaa)
+      |             ~~~~~~~~~~~~~~
+   31 |     println(arr_aaa != arr)
+   32 |     println(arr != arr_aaa)
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:31:10: error: possible type mismatch of compared values of `!=` operation
+   29 |     println(arr_aaa == arr)
+   30 |     println(arr == arr_aaa)
+   31 |     println(arr_aaa != arr)
+      |             ~~~~~~~~~~~~~~
+   32 |     println(arr != arr_aaa)
+   33 |
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:32:10: error: possible type mismatch of compared values of `!=` operation
+   30 |     println(arr == arr_aaa)
+   31 |     println(arr_aaa != arr)
+   32 |     println(arr != arr_aaa)
+      |             ~~~~~~~~~~~~~~
+   33 | 
+   34 |     println(arr_aaa == [0])
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:34:10: error: infix expr: cannot use `[]int` (right expression) as `ArrAaa`
+   32 |     println(arr != arr_aaa)
+   33 | 
+   34 |     println(arr_aaa == [0])
+      |             ~~~~~~~~~~~~~~
+   35 |     println([1] == arr_aaa)
+   36 |     println(arr_aaa != [0])
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:35:10: error: infix expr: cannot use `ArrAaa` (right expression) as `[]int`
+   33 | 
+   34 |     println(arr_aaa == [0])
+   35 |     println([1] == arr_aaa)
+      |             ~~~~~~~~~~~~~~
+   36 |     println(arr_aaa != [0])
+   37 |     println([1] != arr_aaa)
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:36:10: error: infix expr: cannot use `[]int` (right expression) as `ArrAaa`
+   34 |     println(arr_aaa == [0])
+   35 |     println([1] == arr_aaa)
+   36 |     println(arr_aaa != [0])
+      |             ~~~~~~~~~~~~~~
+   37 |     println([1] != arr_aaa)
+   38 | }
+vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv:37:10: error: infix expr: cannot use `ArrAaa` (right expression) as `[]int`
+   35 |     println([1] == arr_aaa)
+   36 |     println(arr_aaa != [0])
+   37 |     println([1] != arr_aaa)
+      |             ~~~~~~~~~~~~~~
+   38 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv
new file mode 100644
index 0000000..36e7d17
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/eq_ne_op_wrong_type_err.vv
@@ -0,0 +1,38 @@
+struct Aaa {
+	i int
+}
+
+type AAaa = Aaa
+
+type Arr = []int
+
+type ArrAaa = Aaa | Arr
+
+fn main() {
+	println(Aaa{} == 10)
+	println(10 == Aaa{})
+	println(Aaa{} != 10)
+	println(10 != Aaa{})
+
+	println(Aaa{0} == AAaa{0})
+	println(AAaa{0} == Aaa{0})
+	println(AAaa{1} != Aaa{1})
+	println(Aaa{1} != AAaa{1})
+
+	arr := Arr([0])
+	println(arr == [0])
+	println([1] == arr)
+	println(arr != [0])
+	println([1] != arr)
+
+	arr_aaa := ArrAaa(arr)
+	println(arr_aaa == arr)
+	println(arr == arr_aaa)
+	println(arr_aaa != arr)
+	println(arr != arr_aaa)
+
+	println(arr_aaa == [0])
+	println([1] == arr_aaa)
+	println(arr_aaa != [0])
+	println([1] != arr_aaa)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_fn_with_0_args.out b/v_windows/v/old/vlib/v/checker/tests/error_fn_with_0_args.out
new file mode 100644
index 0000000..c4aceee
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_fn_with_0_args.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/error_fn_with_0_args.vv:2:9: error: expected 1 arguments, but got 0
+    1 | fn abc() ? {
+    2 |     return error()
+      |            ~~~~~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_fn_with_0_args.vv b/v_windows/v/old/vlib/v/checker/tests/error_fn_with_0_args.vv
new file mode 100644
index 0000000..ebbfe47
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_fn_with_0_args.vv
@@ -0,0 +1,3 @@
+fn abc() ? {
+	return error()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_crlf_ending.out b/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_crlf_ending.out
new file mode 100644
index 0000000..5e4630e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_crlf_ending.out
@@ -0,0 +1,4 @@
+vlib/v/checker/tests/error_with_comment_with_crlf_ending.vv:2:6: error: unexpected name `should`
+    1 | // Empty lines don't cause an issue but as soon as there's a comment with a CRLF ending, it fails
+    2 | This should cause an error!
+      |      ~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_crlf_ending.vv b/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_crlf_ending.vv
new file mode 100644
index 0000000..256462a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_crlf_ending.vv
@@ -0,0 +1,2 @@
+// Empty lines don't cause an issue but as soon as there's a comment with a CRLF ending, it fails

+This should cause an error!
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_lf_ending.out b/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_lf_ending.out
new file mode 100644
index 0000000..fcf3524
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_lf_ending.out
@@ -0,0 +1,4 @@
+vlib/v/checker/tests/error_with_comment_with_lf_ending.vv:2:6: error: unexpected name `should`
+    1 | // Empty lines don't cause an issue but as soon as there's a comment with a CRLF ending, it fails
+    2 | This should cause an error!
+      |      ~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_lf_ending.vv b/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_lf_ending.vv
new file mode 100644
index 0000000..003d44e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_with_comment_with_lf_ending.vv
@@ -0,0 +1,2 @@
+// Empty lines don't cause an issue but as soon as there's a comment with a CRLF ending, it fails
+This should cause an error!
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_with_several_comments_with_crlf_ending.out b/v_windows/v/old/vlib/v/checker/tests/error_with_several_comments_with_crlf_ending.out
new file mode 100644
index 0000000..d1b88fa
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_with_several_comments_with_crlf_ending.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/error_with_several_comments_with_crlf_ending.vv:9:2: error: undefined ident: `a` (use `:=` to declare a variable)
+    7 | fn main() {
+    8 |     func1()
+    9 |     a = 2
+      |     ^
+   10 |     println('a is $a')
+   11 | }
+vlib/v/checker/tests/error_with_several_comments_with_crlf_ending.vv:10:17: error: undefined ident: `a`
+    8 |     func1()
+    9 |     a = 2
+   10 |     println('a is $a')
+      |                    ^
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_with_several_comments_with_crlf_ending.vv b/v_windows/v/old/vlib/v/checker/tests/error_with_several_comments_with_crlf_ending.vv
new file mode 100644
index 0000000..09b22be
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_with_several_comments_with_crlf_ending.vv
@@ -0,0 +1,11 @@
+// Comment line 1

+// Comment line 2

+fn func1() {

+	println('Inside func 1')

+}

+

+fn main() {

+	func1()

+	a = 2

+	println('a is $a')

+}

diff --git a/v_windows/v/old/vlib/v/checker/tests/error_with_unicode.out b/v_windows/v/old/vlib/v/checker/tests/error_with_unicode.out
new file mode 100644
index 0000000..78ea832
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_with_unicode.out
@@ -0,0 +1,56 @@
+vlib/v/checker/tests/error_with_unicode.vv:5:17: error: cannot use `int literal` as `string` in argument 2 to `f1`
+    3 | 
+    4 | fn main() {
+    5 |     f1('🐀🐈', 0)
+      |                ^
+    6 |     f2(0, '🐟🐧')
+    7 |     mut n := 0
+vlib/v/checker/tests/error_with_unicode.vv:6:8: error: cannot use `string` as `int` in argument 2 to `f2`
+    4 | fn main() {
+    5 |     f1('🐀🐈', 0)
+    6 |     f2(0, '🐟🐧')
+      |           ~~~~~~
+    7 |     mut n := 0
+    8 |     n = '漢字'
+vlib/v/checker/tests/error_with_unicode.vv:8:6: error: cannot assign to `n`: expected `int`, not `string`
+    6 |     f2(0, '🐟🐧')
+    7 |     mut n := 0
+    8 |     n = '漢字'
+      |         ~~~~~~
+    9 |     n = 'ひらがな'
+   10 |     n = '简体字'
+vlib/v/checker/tests/error_with_unicode.vv:9:6: error: cannot assign to `n`: expected `int`, not `string`
+    7 |     mut n := 0
+    8 |     n = '漢字'
+    9 |     n = 'ひらがな'
+      |         ~~~~~~~~~~
+   10 |     n = '简体字'
+   11 |     n = '繁體字'
+vlib/v/checker/tests/error_with_unicode.vv:10:6: error: cannot assign to `n`: expected `int`, not `string`
+    8 |     n = '漢字'
+    9 |     n = 'ひらがな'
+   10 |     n = '简体字'
+      |         ~~~~~~~~
+   11 |     n = '繁體字'
+   12 |     n = '한글'
+vlib/v/checker/tests/error_with_unicode.vv:11:6: error: cannot assign to `n`: expected `int`, not `string`
+    9 |     n = 'ひらがな'
+   10 |     n = '简体字'
+   11 |     n = '繁體字'
+      |         ~~~~~~~~
+   12 |     n = '한글'
+   13 |     n = 'Кириллица'
+vlib/v/checker/tests/error_with_unicode.vv:12:6: error: cannot assign to `n`: expected `int`, not `string`
+   10 |     n = '简体字'
+   11 |     n = '繁體字'
+   12 |     n = '한글'
+      |         ~~~~~~
+   13 |     n = 'Кириллица'
+   14 |     _ = n
+vlib/v/checker/tests/error_with_unicode.vv:13:6: error: cannot assign to `n`: expected `int`, not `string`
+   11 |     n = '繁體字'
+   12 |     n = '한글'
+   13 |     n = 'Кириллица'
+      |         ~~~~~~~~~~~
+   14 |     _ = n
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/error_with_unicode.vv b/v_windows/v/old/vlib/v/checker/tests/error_with_unicode.vv
new file mode 100644
index 0000000..8299e4e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/error_with_unicode.vv
@@ -0,0 +1,15 @@
+fn f1(_ string, _ string) {}
+fn f2(_ int, _ int) {}
+
+fn main() {
+	f1('🐀🐈', 0)
+	f2(0, '🐟🐧')
+	mut n := 0
+	n = '漢字'
+	n = 'ひらがな'
+	n = '简体字'
+	n = '繁體字'
+	n = '한글'
+	n = 'Кириллица'
+	_ = n
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/expression_should_return_an_option.out b/v_windows/v/old/vlib/v/checker/tests/expression_should_return_an_option.out
new file mode 100644
index 0000000..e150341
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/expression_should_return_an_option.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/expression_should_return_an_option.vv:28:10: error: expression should return an option
+   26 |     }
+   27 |     // should be an checker error:
+   28 |     if x := return_string() {
+      |             ~~~~~~~~~~~~~~~
+   29 |         println('x: $x')
+   30 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/expression_should_return_an_option.vv b/v_windows/v/old/vlib/v/checker/tests/expression_should_return_an_option.vv
new file mode 100644
index 0000000..6b25dbc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/expression_should_return_an_option.vv
@@ -0,0 +1,31 @@
+fn return_optional(fail bool) ?string {
+	if fail {
+		return error('nope')
+	}
+	return 'foo'
+}
+
+fn return_string() string {
+	return 'foo'
+}
+
+fn main() {
+	// works
+	if r := return_optional(false) {
+		println(r)
+	}
+	// works
+	if r := return_optional(false) {
+		println(r)
+	} else {
+		println(err)
+	}
+	// works
+	return_optional(true) or {
+		println(err)
+	}
+	// should be an checker error:
+	if x := return_string() {
+		println('x: $x')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/filter_func_return_nonbool_err.out b/v_windows/v/old/vlib/v/checker/tests/filter_func_return_nonbool_err.out
new file mode 100644
index 0000000..e62f5db
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/filter_func_return_nonbool_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/filter_func_return_nonbool_err.vv:2:25: error: type mismatch, `stringsss` must return a bool
+    1 | fn main() {
+    2 |     list := [1,2,3].filter(stringsss(it))
+      |                            ~~~~~~~~~~~~~
+    3 | }
+    4 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/filter_func_return_nonbool_err.vv b/v_windows/v/old/vlib/v/checker/tests/filter_func_return_nonbool_err.vv
new file mode 100644
index 0000000..a6ecd7a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/filter_func_return_nonbool_err.vv
@@ -0,0 +1,7 @@
+fn main() {
+	list := [1,2,3].filter(stringsss(it))
+}
+
+fn stringsss(arg int) string {
+	return ''
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/filter_on_non_arr_err.out b/v_windows/v/old/vlib/v/checker/tests/filter_on_non_arr_err.out
new file mode 100644
index 0000000..d01f0fd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/filter_on_non_arr_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/filter_on_non_arr_err.vv:2:14: error: unknown method or field: `string.filter`
+    1 | fn main() {
+    2 |     _ := 'test'.filter(it == `t`)
+      |                 ~~~~~~~~~~~~~~~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/filter_on_non_arr_err.vv b/v_windows/v/old/vlib/v/checker/tests/filter_on_non_arr_err.vv
new file mode 100644
index 0000000..ee1bb7c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/filter_on_non_arr_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	_ := 'test'.filter(it == `t`)
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/fixed_array_conv.out b/v_windows/v/old/vlib/v/checker/tests/fixed_array_conv.out
new file mode 100644
index 0000000..211f4b5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fixed_array_conv.out
@@ -0,0 +1,41 @@
+vlib/v/checker/tests/fixed_array_conv.vv:3:3: error: mismatched types `voidptr` and `[2]int`
+    1 | arr := [2,3]!
+    2 | mut p := voidptr(0)
+    3 | p = arr
+      |   ^
+    4 | mut ip := &int(0)
+    5 | ip = arr
+vlib/v/checker/tests/fixed_array_conv.vv:5:4: error: mismatched types `&int` and `[2]int`
+    3 | p = arr
+    4 | mut ip := &int(0)
+    5 | ip = arr
+      |    ^
+    6 | _ = &int(arr)
+    7 | _ = p
+vlib/v/checker/tests/fixed_array_conv.vv:6:5: error: cannot cast a fixed array (use e.g. `&arr[0]` instead)
+    4 | mut ip := &int(0)
+    5 | ip = arr
+    6 | _ = &int(arr)
+      |     ~~~~~~~~~
+    7 | _ = p
+    8 | _ = ip
+vlib/v/checker/tests/fixed_array_conv.vv:11:13: error: cannot use `[2]int` as `voidptr` in argument 1 to `memdup`
+    9 | 
+   10 | unsafe {
+   11 |     _ = memdup(arr, 1)
+      |                ~~~
+   12 |     _ = tos(arr, 1)
+   13 |     fn (p &int){}(arr)
+vlib/v/checker/tests/fixed_array_conv.vv:12:10: error: cannot use `[2]int` as `&byte` in argument 1 to `tos`
+   10 | unsafe {
+   11 |     _ = memdup(arr, 1)
+   12 |     _ = tos(arr, 1)
+      |             ~~~
+   13 |     fn (p &int){}(arr)
+   14 | }
+vlib/v/checker/tests/fixed_array_conv.vv:13:16: error: cannot use `[2]int` as `&int` in argument 1 to `anon`
+   11 |     _ = memdup(arr, 1)
+   12 |     _ = tos(arr, 1)
+   13 |     fn (p &int){}(arr)
+      |                   ~~~
+   14 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/fixed_array_conv.vv b/v_windows/v/old/vlib/v/checker/tests/fixed_array_conv.vv
new file mode 100644
index 0000000..8c343c4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fixed_array_conv.vv
@@ -0,0 +1,14 @@
+arr := [2,3]!
+mut p := voidptr(0)
+p = arr
+mut ip := &int(0)
+ip = arr
+_ = &int(arr)
+_ = p
+_ = ip
+
+unsafe {
+	_ = memdup(arr, 1)
+	_ = tos(arr, 1)
+	fn (p &int){}(arr)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/fixed_array_non_const_size_err.out b/v_windows/v/old/vlib/v/checker/tests/fixed_array_non_const_size_err.out
new file mode 100644
index 0000000..0734920
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fixed_array_non_const_size_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/fixed_array_non_const_size_err.vv:4:12: error: non-constant array bound `size`
+    2 |     size := 2
+    3 |
+    4 |     array := [size]int{}
+      |               ~~~~
+    5 |
+    6 |     println(array)
diff --git a/v_windows/v/old/vlib/v/checker/tests/fixed_array_non_const_size_err.vv b/v_windows/v/old/vlib/v/checker/tests/fixed_array_non_const_size_err.vv
new file mode 100644
index 0000000..eada0cd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fixed_array_non_const_size_err.vv
@@ -0,0 +1,7 @@
+fn main() {
+	size := 2
+
+	array := [size]int{}
+
+	println(array)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/fixed_array_size_err.out b/v_windows/v/old/vlib/v/checker/tests/fixed_array_size_err.out
new file mode 100644
index 0000000..8e3c9ea
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fixed_array_size_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/fixed_array_size_err.vv:4:8: error: fixed size cannot be zero or negative (fixed_size: -1)
+    2 | 
+    3 | fn main() {
+    4 |     a := [size]int{}
+      |           ~~~~
+    5 |     b := [0]byte{}
+    6 |     println(a)
+vlib/v/checker/tests/fixed_array_size_err.vv:5:8: error: fixed size cannot be zero or negative (fixed_size: 0)
+    3 | fn main() {
+    4 |     a := [size]int{}
+    5 |     b := [0]byte{}
+      |           ^
+    6 |     println(a)
+    7 |     println(b)
diff --git a/v_windows/v/old/vlib/v/checker/tests/fixed_array_size_err.vv b/v_windows/v/old/vlib/v/checker/tests/fixed_array_size_err.vv
new file mode 100644
index 0000000..eb27c2b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fixed_array_size_err.vv
@@ -0,0 +1,8 @@
+const size = -1
+
+fn main() {
+	a := [size]int{}
+	b := [0]byte{}
+	println(a)
+	println(b)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_not_integer_err.out b/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_not_integer_err.out
new file mode 100644
index 0000000..8d7b1d8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_not_integer_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/float_lit_exp_not_integer_err.vv:2:17: error: exponential part should be integer
+    1 | fn main() {
+    2 |     println(45e2.5)
+      |                 ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_not_integer_err.vv b/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_not_integer_err.vv
new file mode 100644
index 0000000..a1bd559
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_not_integer_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(45e2.5)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_without_digit_err.out b/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_without_digit_err.out
new file mode 100644
index 0000000..c5be9e2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_without_digit_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/float_lit_exp_without_digit_err.vv:2:14: error: exponent has no digits
+    1 | fn main() {
+    2 |     println(2E)
+      |              ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_without_digit_err.vv b/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_without_digit_err.vv
new file mode 100644
index 0000000..6d3d9f1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/float_lit_exp_without_digit_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(2E)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/float_lit_too_many_points_err.out b/v_windows/v/old/vlib/v/checker/tests/float_lit_too_many_points_err.out
new file mode 100644
index 0000000..cbf085b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/float_lit_too_many_points_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/float_lit_too_many_points_err.vv:2:19: error: too many decimal points in number
+    1 | fn main() {
+    2 |     println(123.45.67)
+      |                   ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/float_lit_too_many_points_err.vv b/v_windows/v/old/vlib/v/checker/tests/float_lit_too_many_points_err.vv
new file mode 100644
index 0000000..e787cab
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/float_lit_too_many_points_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(123.45.67)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/float_modulo_err.out b/v_windows/v/old/vlib/v/checker/tests/float_modulo_err.out
new file mode 100644
index 0000000..a3ee9bf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/float_modulo_err.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/float_modulo_err.vv:2:13: error: float modulo not allowed, use math.fmod() instead
+    1 | fn main() {
+    2 |     println(3.0 % 2.0)
+      |             ~~~
+    3 |     println(f32(3.0) % f32(2.0))
+    4 | }
+vlib/v/checker/tests/float_modulo_err.vv:3:13: error: float modulo not allowed, use math.fmod() instead
+    1 | fn main() {
+    2 |     println(3.0 % 2.0)
+    3 |     println(f32(3.0) % f32(2.0))
+      |             ~~~~~~~~
+    4 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/float_modulo_err.vv b/v_windows/v/old/vlib/v/checker/tests/float_modulo_err.vv
new file mode 100644
index 0000000..6a4d87d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/float_modulo_err.vv
@@ -0,0 +1,4 @@
+fn main() {
+    println(3.0 % 2.0)
+    println(f32(3.0) % f32(2.0))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_args.out b/v_windows/v/old/vlib/v/checker/tests/fn_args.out
new file mode 100644
index 0000000..2df630b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_args.out
@@ -0,0 +1,35 @@
+vlib/v/checker/tests/fn_args.vv:9:6: error: cannot use `&int` as `byte` in argument 1 to `uu8`
+    7 | fn basic() {
+    8 |     v := 4
+    9 |     uu8(&v)
+      |         ~~
+   10 |     arr([5]!)
+   11 |     fun(fn (i &int) {})
+vlib/v/checker/tests/fn_args.vv:10:6: error: cannot use `[1]int` as `[]int` in argument 1 to `arr`
+    8 |     v := 4
+    9 |     uu8(&v)
+   10 |     arr([5]!)
+      |         ~~~~
+   11 |     fun(fn (i &int) {})
+   12 |     fun(fn (ii ...int) {})
+vlib/v/checker/tests/fn_args.vv:11:6: error: cannot use `fn (&int)` as `fn (int)` in argument 1 to `fun`
+    9 |     uu8(&v)
+   10 |     arr([5]!)
+   11 |     fun(fn (i &int) {})
+      |         ~~~~~~~~~~~~~~
+   12 |     fun(fn (ii ...int) {})
+   13 | }
+Details: ``'s expected fn argument: `` is NOT a pointer, but the passed fn argument: `i` is a pointer
+vlib/v/checker/tests/fn_args.vv:12:6: error: cannot use `fn (...int)` as `fn (int)` in argument 1 to `fun`
+   10 |     arr([5]!)
+   11 |     fun(fn (i &int) {})
+   12 |     fun(fn (ii ...int) {})
+      |         ~~~~~~~~~~~~~~~~~
+   13 | }
+   14 |
+vlib/v/checker/tests/fn_args.vv:22:4: error: cannot use `int` as `&S1` in argument 1 to `f`
+   20 | fn ptr() {
+   21 |     v := 4
+   22 |     f(v)
+      |       ^
+   23 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_args.vv b/v_windows/v/old/vlib/v/checker/tests/fn_args.vv
new file mode 100644
index 0000000..5cfdff5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_args.vv
@@ -0,0 +1,23 @@
+fn uu8(a byte) {}
+
+fn arr(a []int) {}
+
+fn fun(a fn (int)) {}
+
+fn basic() {
+	v := 4
+	uu8(&v)
+	arr([5]!)
+	fun(fn (i &int) {})
+	fun(fn (ii ...int) {})
+}
+
+struct S1 {
+}
+
+fn f(p &S1) {}
+
+fn ptr() {
+	v := 4
+	f(v)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_call_no_body.out b/v_windows/v/old/vlib/v/checker/tests/fn_call_no_body.out
new file mode 100644
index 0000000..376fc56
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_call_no_body.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/fn_call_no_body.vv:7:9: error: cannot call a method that does not have a body
+    5 |
+    6 | fn main() {
+    7 |     Foo(0).f()
+      |            ~~~
+    8 |     f()
+    9 | }
+vlib/v/checker/tests/fn_call_no_body.vv:8:2: error: cannot call a function that does not have a body
+    6 | fn main() {
+    7 |     Foo(0).f()
+    8 |     f()
+      |     ~~~
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_call_no_body.vv b/v_windows/v/old/vlib/v/checker/tests/fn_call_no_body.vv
new file mode 100644
index 0000000..1058977
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_call_no_body.vv
@@ -0,0 +1,9 @@
+type Foo = int
+fn (_ Foo) f()
+
+fn f()
+
+fn main() {
+	Foo(0).f()
+	f()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_duplicate.out b/v_windows/v/old/vlib/v/checker/tests/fn_duplicate.out
new file mode 100644
index 0000000..3cf949c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_duplicate.out
@@ -0,0 +1,13 @@
+redefinition of function `main.f`
+vlib/v/checker/tests/fn_duplicate.vv:1:1: conflicting declaration: fn f()
+    1 | fn f() {
+      | ~~~~~~
+    2 |     
+    3 | }
+vlib/v/checker/tests/fn_duplicate.vv:5:1: conflicting declaration: fn f(i int)
+    3 | }
+    4 | 
+    5 | fn f(i int) {
+      | ~~~~~~~~~~~
+    6 |     
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_duplicate.vv b/v_windows/v/old/vlib/v/checker/tests/fn_duplicate.vv
new file mode 100644
index 0000000..08c1dfb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_duplicate.vv
@@ -0,0 +1,7 @@
+fn f() {
+	
+}
+
+fn f(i int) {
+	
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_init_sig.out b/v_windows/v/old/vlib/v/checker/tests/fn_init_sig.out
new file mode 100644
index 0000000..08cb17b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_init_sig.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/fn_init_sig.vv:1:1: error: fn `init` cannot have a return type
+    1 | fn init() int {
+      | ~~~~~~~~~~~~~
+    2 |     return 1
+    3 | }
+vlib/v/checker/tests/fn_init_sig.vv:4:1: error: fn `init` must not be public
+    2 |     return 1
+    3 | }
+    4 | pub fn init() int {
+      | ~~~~~~~~~~~~~~~~~
+    5 |     return 1
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_init_sig.vv b/v_windows/v/old/vlib/v/checker/tests/fn_init_sig.vv
new file mode 100644
index 0000000..bff6d49
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_init_sig.vv
@@ -0,0 +1,6 @@
+fn init() int {
+    return 1
+}
+pub fn init() int {
+    return 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_return_or_err.out b/v_windows/v/old/vlib/v/checker/tests/fn_return_or_err.out
new file mode 100644
index 0000000..ebb4494
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_return_or_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/fn_return_or_err.vv:6:17: error: unexpected `or` block, the function `pop` does not return an optional
+    4 |
+    5 | pub fn next(mut v []Typ) Typ {
+    6 |     return v.pop() or { Typ{} }
+      |                    ~~~~~~~~~~~~
+    7 | }
+    8 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_return_or_err.vv b/v_windows/v/old/vlib/v/checker/tests/fn_return_or_err.vv
new file mode 100644
index 0000000..c303b0a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_return_or_err.vv
@@ -0,0 +1,13 @@
+module main
+
+pub struct Typ {}
+
+pub fn next(mut v []Typ) Typ {
+	return v.pop() or { Typ{} }
+}
+
+fn main() {
+	mut v := [Typ{}]
+	last := next(mut v)
+	println('$last')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_type_exists.out b/v_windows/v/old/vlib/v/checker/tests/fn_type_exists.out
new file mode 100644
index 0000000..c6aa40f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_type_exists.out
@@ -0,0 +1,10 @@
+vlib/v/checker/tests/fn_type_exists.vv:1:34: error: unknown type `Pants`
+    1 | type PantsCreator = fn (a Shirt) Pants
+      |                                  ~~~~~
+    2 |
+    3 | type PantsConsumer = fn (p Pants)
+vlib/v/checker/tests/fn_type_exists.vv:3:28: error: unknown type `Pants`
+    1 | type PantsCreator = fn (a Shirt) Pants
+    2 |
+    3 | type PantsConsumer = fn (p Pants)
+      |                            ~~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_type_exists.vv b/v_windows/v/old/vlib/v/checker/tests/fn_type_exists.vv
new file mode 100644
index 0000000..04ead19
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_type_exists.vv
@@ -0,0 +1,3 @@
+type PantsCreator = fn (a Shirt) Pants
+
+type PantsConsumer = fn (p Pants)
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_var.out b/v_windows/v/old/vlib/v/checker/tests/fn_var.out
new file mode 100644
index 0000000..d3487a1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_var.out
@@ -0,0 +1,23 @@
+vlib/v/checker/tests/fn_var.vv:1:10: error: missing return at the end of an anonymous function
+    1 | mut f := fn(i int) byte {}
+      |          ~~~~~~~~~~~~~~~~~
+    2 | f = 4
+    3 | mut p := &f
+vlib/v/checker/tests/fn_var.vv:2:5: error: cannot assign to `f`: expected `fn (int) byte`, not `int literal`
+    1 | mut f := fn(i int) byte {}
+    2 | f = 4
+      |     ^
+    3 | mut p := &f
+    4 | p = &[f]
+vlib/v/checker/tests/fn_var.vv:4:5: error: cannot assign to `p`: expected `&fn (int) byte`, not `&[]fn (int) byte`
+    2 | f = 4
+    3 | mut p := &f
+    4 | p = &[f]
+      |     ^
+    5 | _ = p
+    6 | i := 0
+vlib/v/checker/tests/fn_var.vv:8:31: error: undefined ident: `i`
+    6 | i := 0
+    7 | println(i)
+    8 | f = fn(mut a []int) { println(i) }
+      |                               ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_var.vv b/v_windows/v/old/vlib/v/checker/tests/fn_var.vv
new file mode 100644
index 0000000..0a48b5d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_var.vv
@@ -0,0 +1,8 @@
+mut f := fn(i int) byte {}
+f = 4
+mut p := &f
+p = &[f]
+_ = p
+i := 0
+println(i)
+f = fn(mut a []int) { println(i) }
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_variadic.out b/v_windows/v/old/vlib/v/checker/tests/fn_variadic.out
new file mode 100644
index 0000000..f14183a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_variadic.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/fn_variadic.vv:3:8: error: when forwarding a variadic variable, it must be the final argument
+    1 | fn f(vi ...int) int {
+    2 |     _ = f(...vi) // OK
+    3 |     _ = f(...vi, 2)
+      |           ~~~~~
+    4 |     return 0
+    5 | }
+vlib/v/checker/tests/fn_variadic.vv:11:10: error: when forwarding a variadic variable, it must be the final argument
+    9 | fn (s S1) m(vi ...int) int {
+   10 |     _ = s.m(...vi) // OK
+   11 |     _ = s.m(...vi, 2)
+      |             ~~~~~
+   12 |     return 0
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/fn_variadic.vv b/v_windows/v/old/vlib/v/checker/tests/fn_variadic.vv
new file mode 100644
index 0000000..b7faad7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/fn_variadic.vv
@@ -0,0 +1,13 @@
+fn f(vi ...int) int {
+	_ = f(...vi) // OK
+	_ = f(...vi, 2)
+	return 0
+}
+
+struct S1 {}
+
+fn (s S1) m(vi ...int) int {
+	_ = s.m(...vi) // OK
+	_ = s.m(...vi, 2)
+	return 0
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_index_optional.out b/v_windows/v/old/vlib/v/checker/tests/for_in_index_optional.out
new file mode 100644
index 0000000..bbab32a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_index_optional.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/for_in_index_optional.vv:3:18: error: for in: cannot index `?[]string`
+    1 | import os
+    2 | fn main() {
+    3 |   for file in os.ls('.') {
+      |                  ~~~~~~~
+    4 |     println(file)
+    5 |   }
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_index_optional.vv b/v_windows/v/old/vlib/v/checker/tests/for_in_index_optional.vv
new file mode 100644
index 0000000..c384c79
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_index_optional.vv
@@ -0,0 +1,6 @@
+import os
+fn main() {
+  for file in os.ls('.') {
+    println(file)
+  }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_index_type.out b/v_windows/v/old/vlib/v/checker/tests/for_in_index_type.out
new file mode 100644
index 0000000..376ba73
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_index_type.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/for_in_index_type.vv:2:11: error: for in: cannot index `int literal`
+    1 | fn main() {
+    2 |     for a in 52 {
+      |              ~~
+    3 |         println(a)
+    4 |     }
+vlib/v/checker/tests/for_in_index_type.vv:3:3: error: `println` can not print void expressions
+    1 | fn main() {
+    2 |     for a in 52 {
+    3 |         println(a)
+      |         ~~~~~~~~~~
+    4 |     }
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_index_type.vv b/v_windows/v/old/vlib/v/checker/tests/for_in_index_type.vv
new file mode 100644
index 0000000..cbc26ae
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_index_type.vv
@@ -0,0 +1,5 @@
+fn main() {
+	for a in 52 {
+		println(a)
+	}
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_map_one_variable_err.out b/v_windows/v/old/vlib/v/checker/tests/for_in_map_one_variable_err.out
new file mode 100644
index 0000000..d7c6579
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_map_one_variable_err.out
@@ -0,0 +1,8 @@
+vlib/v/checker/tests/for_in_map_one_variable_err.vv:3:6: error: declare a key and a value variable when ranging a map: `for key, val in map {`
+use `_` if you do not need the variable
+    1 | fn main() {
+    2 |     kvs := map{'foo':'bar'}
+    3 |     for k in kvs {
+      |         ^
+    4 |         println('$k')
+    5 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_map_one_variable_err.vv b/v_windows/v/old/vlib/v/checker/tests/for_in_map_one_variable_err.vv
new file mode 100644
index 0000000..9297280
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_map_one_variable_err.vv
@@ -0,0 +1,6 @@
+fn main() {
+	kvs := map{'foo':'bar'}
+	for k in kvs {
+		println('$k')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_mut_val_type.out b/v_windows/v/old/vlib/v/checker/tests/for_in_mut_val_type.out
new file mode 100644
index 0000000..d898cf7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_mut_val_type.out
@@ -0,0 +1,42 @@
+vlib/v/checker/tests/for_in_mut_val_type.vv:3:15: error: `a1` is immutable, it cannot be changed
+    1 | fn main() {
+    2 |     a1 := [1, 2, 3]
+    3 |     for mut j in a1 {
+      |                  ~~
+    4 |         j *= 2
+    5 |     }
+vlib/v/checker/tests/for_in_mut_val_type.vv:7:15: error: `a2` is immutable, it cannot be changed
+    5 |     }
+    6 |     a2 := [1, 2, 3]!
+    7 |     for mut j in a2 {
+      |                  ~~
+    8 |         j *= 2
+    9 |     }
+vlib/v/checker/tests/for_in_mut_val_type.vv:11:18: error: `m` is immutable, it cannot be changed
+    9 |     }
+   10 |     m := map{'aa': 1, 'bb': 2}
+   11 |     for _, mut j in m {
+      |                     ^
+   12 |         j *= 2
+   13 |     }
+vlib/v/checker/tests/for_in_mut_val_type.vv:14:15: error: array literal is immutable, it cannot be changed
+   12 |         j *= 2
+   13 |     }
+   14 |     for mut j in [1, 2, 3] {
+      |                  ~~~~~~~~~
+   15 |         j *= 2
+   16 |     }
+vlib/v/checker/tests/for_in_mut_val_type.vv:17:15: error: array literal is immutable, it cannot be changed
+   15 |         j *= 2
+   16 |     }
+   17 |     for mut j in [1, 2, 3]! {
+      |                  ~~~~~~~~~~
+   18 |         j *= 2
+   19 |     }
+vlib/v/checker/tests/for_in_mut_val_type.vv:20:21: error: map literal is immutable, it cannot be changed
+   18 |         j *= 2
+   19 |     }
+   20 |     for _, mut j in map{'aa': 1, 'bb': 2} {
+      |                        ~~~~~~~~~~~~~~~~~~
+   21 |         j *= 2
+   22 |     }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_mut_val_type.vv b/v_windows/v/old/vlib/v/checker/tests/for_in_mut_val_type.vv
new file mode 100644
index 0000000..664fb66
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_mut_val_type.vv
@@ -0,0 +1,23 @@
+fn main() {
+	a1 := [1, 2, 3]
+	for mut j in a1 {
+		j *= 2
+	}
+	a2 := [1, 2, 3]!
+	for mut j in a2 {
+		j *= 2
+	}
+	m := map{'aa': 1, 'bb': 2}
+	for _, mut j in m {
+		j *= 2
+	}
+	for mut j in [1, 2, 3] {
+		j *= 2
+	}
+	for mut j in [1, 2, 3]! {
+		j *= 2
+	}
+	for _, mut j in map{'aa': 1, 'bb': 2} {
+		j *= 2
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_range_not_match_type.out b/v_windows/v/old/vlib/v/checker/tests/for_in_range_not_match_type.out
new file mode 100644
index 0000000..d969830
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_range_not_match_type.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/for_in_range_not_match_type.vv:2:11: error: range types do not match
+    1 | fn main() {
+    2 |     for i in 10..10.5 {
+      |              ~~
+    3 |         println(i)
+    4 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_range_not_match_type.vv b/v_windows/v/old/vlib/v/checker/tests/for_in_range_not_match_type.vv
new file mode 100644
index 0000000..8b15863
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_range_not_match_type.vv
@@ -0,0 +1,5 @@
+fn main() {
+	for i in 10..10.5 {
+		println(i)
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_range_string_type.out b/v_windows/v/old/vlib/v/checker/tests/for_in_range_string_type.out
new file mode 100644
index 0000000..4d3d531
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_range_string_type.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/for_in_range_string_type.vv:2:11: error: range type can not be string
+    1 | fn main() {
+    2 |     for i in 'a'..'b' {
+      |              ~~~
+    3 |         println(i)
+    4 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_in_range_string_type.vv b/v_windows/v/old/vlib/v/checker/tests/for_in_range_string_type.vv
new file mode 100644
index 0000000..a459398
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_in_range_string_type.vv
@@ -0,0 +1,5 @@
+fn main() {
+	for i in 'a'..'b' {
+		println(i)
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_match_err.out b/v_windows/v/old/vlib/v/checker/tests/for_match_err.out
new file mode 100644
index 0000000..9c90a9e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_match_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/for_match_err.vv:3:7: error: cannot use `match` in `for` loop
+    1 | fn main() {
+    2 |   mut a := 2
+    3 |   for match a {
+      |       ~~~~~
+    4 |         2 {
+    5 |             println('a == 2')
diff --git a/v_windows/v/old/vlib/v/checker/tests/for_match_err.vv b/v_windows/v/old/vlib/v/checker/tests/for_match_err.vv
new file mode 100644
index 0000000..910f39f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/for_match_err.vv
@@ -0,0 +1,15 @@
+fn main() {
+  mut a := 2
+  for match a {
+		2 {
+			println('a == 2')
+			a = 0
+		}
+		0 {
+			println('a == 0')	
+		}
+		else {
+			println('unexpected branch')
+		}
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_arg_mutable_err.out b/v_windows/v/old/vlib/v/checker/tests/function_arg_mutable_err.out
new file mode 100644
index 0000000..e676a78
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_arg_mutable_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/function_arg_mutable_err.vv:1:18: error: mutable arguments are only allowed for arrays, interfaces, maps, pointers, structs or their aliases
+return values instead: `fn foo(mut n int) {` => `fn foo(n int) int {`
+    1 | fn mod_ptr(mut a int) {
+      |                  ~~~
+    2 |     a = 77
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_arg_mutable_err.vv b/v_windows/v/old/vlib/v/checker/tests/function_arg_mutable_err.vv
new file mode 100644
index 0000000..30165cb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_arg_mutable_err.vv
@@ -0,0 +1,8 @@
+fn mod_ptr(mut a int) {
+	a = 77
+}
+
+fn main() {
+  println('hello')
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_arg_redefinition.out b/v_windows/v/old/vlib/v/checker/tests/function_arg_redefinition.out
new file mode 100644
index 0000000..e540131
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_arg_redefinition.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/function_arg_redefinition.vv:1:17: error: redefinition of parameter `para1`
+    1 | fn f(para1 int, para1 f32) int {
+      |                 ~~~~~
+    2 |     return para1
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_arg_redefinition.vv b/v_windows/v/old/vlib/v/checker/tests/function_arg_redefinition.vv
new file mode 100644
index 0000000..0618fba
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_arg_redefinition.vv
@@ -0,0 +1,7 @@
+fn f(para1 int, para1 f32) int {
+	return para1
+}
+
+fn main() {
+	a := f(11, 1.1)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_count_of_args_mismatch_err.out b/v_windows/v/old/vlib/v/checker/tests/function_count_of_args_mismatch_err.out
new file mode 100644
index 0000000..d9ad12e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_count_of_args_mismatch_err.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/function_count_of_args_mismatch_err.vv:8:13: error: expected 1 arguments, but got 3
+    6 | 
+    7 | fn main() {
+    8 |     test(true, false, 1)
+      |                ~~~~~~~~
+    9 |     test()
+   10 |     test2(true, false, 1)
+vlib/v/checker/tests/function_count_of_args_mismatch_err.vv:9:2: error: expected 1 arguments, but got 0
+    7 | fn main() {
+    8 |     test(true, false, 1)
+    9 |     test()
+      |     ~~~~~~
+   10 |     test2(true, false, 1)
+   11 |     test2(true)
+vlib/v/checker/tests/function_count_of_args_mismatch_err.vv:10:21: error: expected 2 arguments, but got 3
+    8 |     test(true, false, 1)
+    9 |     test()
+   10 |     test2(true, false, 1)
+      |                        ^
+   11 |     test2(true)
+   12 | }
+vlib/v/checker/tests/function_count_of_args_mismatch_err.vv:11:2: error: expected 2 arguments, but got 1
+    9 |     test()
+   10 |     test2(true, false, 1)
+   11 |     test2(true)
+      |     ~~~~~~~~~~~
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_count_of_args_mismatch_err.vv b/v_windows/v/old/vlib/v/checker/tests/function_count_of_args_mismatch_err.vv
new file mode 100644
index 0000000..00fe212
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_count_of_args_mismatch_err.vv
@@ -0,0 +1,12 @@
+fn test(b bool) {
+}
+
+fn test2<T>(b bool, v T) {
+}
+
+fn main() {
+	test(true, false, 1)
+	test()
+	test2(true, false, 1)
+	test2(true)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_missing_return_type.out b/v_windows/v/old/vlib/v/checker/tests/function_missing_return_type.out
new file mode 100644
index 0000000..73292af
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_missing_return_type.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/function_missing_return_type.vv:1:1: error: missing return at end of function `h`
+    1 | fn h() int {
+      | ~~~~~~~~~~
+    2 | }
+    3 |
+vlib/v/checker/tests/function_missing_return_type.vv:12:1: error: missing return at end of function `abc`
+   10 | }
+   11 | 
+   12 | fn (s Abc) abc() &int {
+      | ~~~~~~~~~~~~~~~~~~~~~
+   13 |     if true {
+   14 |         return &s.x
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_missing_return_type.vv b/v_windows/v/old/vlib/v/checker/tests/function_missing_return_type.vv
new file mode 100644
index 0000000..74d8cc1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_missing_return_type.vv
@@ -0,0 +1,22 @@
+fn h() int {
+}
+
+struct Abc {
+	x int
+}
+
+fn (s Abc) panic(message string) {
+	println('called ${@METHOD} with message: $message')
+}
+
+fn (s Abc) abc() &int {
+	if true {
+		return &s.x
+	}
+	s.panic(@FN)
+}
+
+fn main() {
+	d := h()
+	println('$d')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_variadic_arg_array_decompose.out b/v_windows/v/old/vlib/v/checker/tests/function_variadic_arg_array_decompose.out
new file mode 100644
index 0000000..f72b6e0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_variadic_arg_array_decompose.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/function_variadic_arg_array_decompose.vv:11:10: error: too many arguments in call to `sum`
+    9 | fn main() {
+   10 |     b := [5, 6, 7]
+   11 |     println(sum(1, 2, ...b))
+      |             ~~~~~~~~~~~~~~~
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_variadic_arg_array_decompose.vv b/v_windows/v/old/vlib/v/checker/tests/function_variadic_arg_array_decompose.vv
new file mode 100644
index 0000000..27fa0c2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_variadic_arg_array_decompose.vv
@@ -0,0 +1,12 @@
+fn sum(a ...int) int {
+	mut total := 0
+	for x in a {
+		total += x
+	}
+	return total
+}
+
+fn main() {
+	b := [5, 6, 7]
+	println(sum(1, 2, ...b))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_wrong_arg_type.out b/v_windows/v/old/vlib/v/checker/tests/function_wrong_arg_type.out
new file mode 100644
index 0000000..07e4fc8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_wrong_arg_type.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/function_wrong_arg_type.vv:7:9: error: cannot use `f64` as `int` in argument 1 to `f`
+    5 | fn main() {
+    6 |     a := 12.3
+    7 |     q := f(a)
+      |            ^
+    8 |     println('$q')
+    9 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_wrong_arg_type.vv b/v_windows/v/old/vlib/v/checker/tests/function_wrong_arg_type.vv
new file mode 100644
index 0000000..6cd3fbb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_wrong_arg_type.vv
@@ -0,0 +1,9 @@
+fn f(x int) int {
+	return x+x
+}
+
+fn main() {
+	a := 12.3
+	q := f(a)
+	println('$q')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_wrong_return_type.out b/v_windows/v/old/vlib/v/checker/tests/function_wrong_return_type.out
new file mode 100644
index 0000000..070d573
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_wrong_return_type.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/function_wrong_return_type.vv:2:9: error: cannot use `float literal` as type `int` in return argument
+    1 | fn h() int {
+    2 |     return 3.14
+      |            ~~~~
+    3 | }
+    4 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/function_wrong_return_type.vv b/v_windows/v/old/vlib/v/checker/tests/function_wrong_return_type.vv
new file mode 100644
index 0000000..0c47628
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/function_wrong_return_type.vv
@@ -0,0 +1,8 @@
+fn h() int {
+	return 3.14
+}
+
+fn main() {
+	d := h()
+	println('$d')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.out b/v_windows/v/old/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.out
new file mode 100644
index 0000000..502f2b8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv:26:1: error: generic function declaration must specify generic type names, e.g. foo<T>
+   24 | }
+   25 |
+   26 | fn g_worker(g Generic<T>) {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~
+   27 |     t := <-g.ch
+   28 |     handle(t)
+vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv:32:1: error: generic function declaration must specify generic type names, e.g. foo<T>
+   30 | }
+   31 |
+   32 | fn handle(t T) {
+      | ~~~~~~~~~~~~~~
+   33 |     println("hi")
+   34 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv b/v_windows/v/old/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv
new file mode 100644
index 0000000..cc001e9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv
@@ -0,0 +1,34 @@
+struct Generic<T> {
+	ch chan T
+}
+
+struct Concrete {
+	msg string
+}
+
+fn main() {
+	g := create_generic_t<Concrete>()
+	g.ch <- Concrete{
+		msg: 'hello'
+	}
+}
+
+fn create_generic_t<T>() Generic<T> {
+	g := Generic{
+		ch: chan T{}
+	}
+
+	go g_worker(g)
+
+	return g
+}
+
+fn g_worker(g Generic<T>) {
+	t := <-g.ch
+	handle(t)
+	// println("${t.msg}")
+}
+
+fn handle(t T) {
+	println("hi")
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generic_param_used_as_an_array_err.out b/v_windows/v/old/vlib/v/checker/tests/generic_param_used_as_an_array_err.out
new file mode 100644
index 0000000..eb4ee7c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generic_param_used_as_an_array_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/generic_param_used_as_an_array_err.vv:2:10: error: generic type T does not support indexing, pass an array, or a reference instead, e.g. []T or &T
+    1 | fn test<T>(arr T) {
+    2 |     a := arr[1]
+      |             ~~~
+    3 |     println(a)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generic_param_used_as_an_array_err.vv b/v_windows/v/old/vlib/v/checker/tests/generic_param_used_as_an_array_err.vv
new file mode 100644
index 0000000..f545b77
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generic_param_used_as_an_array_err.vv
@@ -0,0 +1,12 @@
+fn test<T>(arr T) {
+	a := arr[1]
+	println(a)
+}
+
+fn main() {
+	a := [1, 2, 3]!
+	test(a)
+
+	b := ['a', 'b', 'c']!
+	test(b)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generic_sumtype_invalid_variant.out b/v_windows/v/old/vlib/v/checker/tests/generic_sumtype_invalid_variant.out
new file mode 100644
index 0000000..c82df9e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generic_sumtype_invalid_variant.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/generic_sumtype_invalid_variant.vv:5:7: error: `MultiGeneric<bool,int,string>` has no variant `u64`
+    3 | fn main() {
+    4 |     mut m := MultiGeneric<bool, int, string>(true)
+    5 |     if m is u64 {
+      |          ~~
+    6 |         println('hi')
+    7 |     }
+vlib/v/checker/tests/generic_sumtype_invalid_variant.vv:8:7: error: `MultiGeneric<bool,int,string>` has no variant `X`
+    6 |         println('hi')
+    7 |     }
+    8 |     if m is X {
+      |          ~~
+    9 |         println('hi again')
+   10 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generic_sumtype_invalid_variant.vv b/v_windows/v/old/vlib/v/checker/tests/generic_sumtype_invalid_variant.vv
new file mode 100644
index 0000000..3cde35b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generic_sumtype_invalid_variant.vv
@@ -0,0 +1,11 @@
+type MultiGeneric<X, Y, Z> = X | Y | Z
+
+fn main() {
+	mut m := MultiGeneric<bool, int, string>(true)
+	if m is u64 {
+		println('hi')
+	}
+	if m is X {
+		println('hi again')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_arg_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_arg_mismatch.out
new file mode 100644
index 0000000..f6913f5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_arg_mismatch.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/generics_fn_called_arg_mismatch.vv:6:15: error: cannot use `int literal` as `bool` in argument 1 to `foo`
+    4 |
+    5 | fn main() {
+    6 |     foo<bool>(1)
+      |               ^
+    7 |     foo<bool>(2.2)
+    8 |     foo<string>(true)
+vlib/v/checker/tests/generics_fn_called_arg_mismatch.vv:7:15: error: cannot use `float literal` as `bool` in argument 1 to `foo`
+    5 | fn main() {
+    6 |     foo<bool>(1)
+    7 |     foo<bool>(2.2)
+      |               ~~~
+    8 |     foo<string>(true)
+    9 |     foo<int>('aaa')
+vlib/v/checker/tests/generics_fn_called_arg_mismatch.vv:8:17: error: cannot use `bool` as `string` in argument 1 to `foo`
+    6 |     foo<bool>(1)
+    7 |     foo<bool>(2.2)
+    8 |     foo<string>(true)
+      |                 ~~~~
+    9 |     foo<int>('aaa')
+   10 | }
+vlib/v/checker/tests/generics_fn_called_arg_mismatch.vv:9:14: error: cannot use `string` as `int` in argument 1 to `foo`
+    7 |     foo<bool>(2.2)
+    8 |     foo<string>(true)
+    9 |     foo<int>('aaa')
+      |              ~~~~~
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_arg_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_arg_mismatch.vv
new file mode 100644
index 0000000..1960a54
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_arg_mismatch.vv
@@ -0,0 +1,10 @@
+fn foo<T>(b T) {
+    println(b)
+}
+
+fn main() {
+    foo<bool>(1)
+    foo<bool>(2.2)
+    foo<string>(true)
+    foo<int>('aaa')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_multi_args_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_multi_args_mismatch.out
new file mode 100644
index 0000000..3f23d6b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_multi_args_mismatch.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/generics_fn_called_multi_args_mismatch.vv:3:13: error: cannot use `[]rune` as `string` in argument 2 to `foo_str`
+    1 | fn main() {
+    2 |     x := 'ab'.runes()[..1]
+    3 |     foo_str(1, x)
+      |                ^
+    4 |
+    5 |     foo := Foo<int>{}
+vlib/v/checker/tests/generics_fn_called_multi_args_mismatch.vv:6:11: error: cannot use `[]rune` as `string` in argument 1 to `Foo<int>.info`
+    4 |
+    5 |     foo := Foo<int>{}
+    6 |     foo.info(x)
+      |              ^
+    7 | }
+    8 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_multi_args_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_multi_args_mismatch.vv
new file mode 100644
index 0000000..fdbdf4d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_multi_args_mismatch.vv
@@ -0,0 +1,17 @@
+fn main() {
+	x := 'ab'.runes()[..1]
+	foo_str(1, x)
+
+	foo := Foo<int>{}
+	foo.info(x)
+}
+
+fn foo_str<T>(b T, a string) {
+}
+
+struct Foo<T> {
+	t T
+}
+
+fn (f Foo<T>) info(a string) {
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_no_arg_err.out b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_no_arg_err.out
new file mode 100644
index 0000000..4212808
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_no_arg_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/generics_fn_called_no_arg_err.vv:13:10: error: no argument generic function must add concrete types, e.g. foo<int>()
+   11 |
+   12 | fn main() {
+   13 |     q := new_queue()
+      |          ~~~~~~~~~~~
+   14 |     println(q)
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_no_arg_err.vv b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_no_arg_err.vv
new file mode 100644
index 0000000..a05e1d5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_no_arg_err.vv
@@ -0,0 +1,15 @@
+struct Queue<T>{
+    buffer []T
+}
+
+fn new_queue<T>() Queue<T> {
+    q := Queue<T>{
+        buffer: []T{cap: 1024}
+    }
+    return q
+}
+
+fn main() {
+    q := new_queue()
+    println(q)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_outside_of_generic_fn.out b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_outside_of_generic_fn.out
new file mode 100644
index 0000000..ec84b67
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_outside_of_generic_fn.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/generics_fn_called_outside_of_generic_fn.vv:4:2: error: generic fn using generic types cannot be called outside of generic fn
+    2 |
+    3 | fn main() {
+    4 |     foo<T>()
+      |     ~~~~~~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_outside_of_generic_fn.vv b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_outside_of_generic_fn.vv
new file mode 100644
index 0000000..c8b72c2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_outside_of_generic_fn.vv
@@ -0,0 +1,5 @@
+fn foo<T>() {}
+
+fn main() {
+	foo<T>()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_variadic_arg_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_variadic_arg_mismatch.out
new file mode 100644
index 0000000..cf4d3b2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_variadic_arg_mismatch.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/generics_fn_called_variadic_arg_mismatch.vv:12:11: error: cannot use `[]int` as `int` in argument 1 to `max`
+   10 |
+   11 | fn main() {
+   12 |     a := max([1, 2, 3, 4])
+      |              ~~~~~~~~~~~~
+   13 |     println(a)
+   14 |
+vlib/v/checker/tests/generics_fn_called_variadic_arg_mismatch.vv:15:16: error: cannot use `[]int` as `int` in argument 1 to `max`
+   13 |     println(a)
+   14 |
+   15 |     b := max<int>([1, 2, 3, 4])
+      |                   ~~~~~~~~~~~~
+   16 |     println(b)
+   17 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_variadic_arg_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_variadic_arg_mismatch.vv
new file mode 100644
index 0000000..e322a64
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_called_variadic_arg_mismatch.vv
@@ -0,0 +1,17 @@
+fn max<T>(a ...T) T {
+	mut max := a[0]
+	for item in a[1..] {
+		if max < item {
+			max = item
+		}
+	}
+	return max
+}
+
+fn main() {
+	a := max([1, 2, 3, 4])
+	println(a)
+
+	b := max<int>([1, 2, 3, 4])
+	println(b)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_return_generic_struct_err.out b/v_windows/v/old/vlib/v/checker/tests/generics_fn_return_generic_struct_err.out
new file mode 100644
index 0000000..b6efe45
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_return_generic_struct_err.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv:13:32: error: return generic struct in fn declaration must specify the generic type names, e.g. Foo<T>
+   11 | }
+   12 |
+   13 | pub fn new_channel_struct<T>() GenericChannelStruct {
+      |                                ~~~~~~~~~~~~~~~~~~~~
+   14 |     d := GenericChannelStruct{
+   15 |         ch: chan T{}
+vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv:17:9: error: cannot use `GenericChannelStruct<Simple>` as type `GenericChannelStruct` in return argument
+   15 |         ch: chan T{}
+   16 |     }
+   17 |     return d
+      |            ^
+   18 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv b/v_windows/v/old/vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv
new file mode 100644
index 0000000..0f9a5d5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv
@@ -0,0 +1,18 @@
+struct GenericChannelStruct<T> {
+	ch chan T
+}
+
+struct Simple {
+	msg string
+}
+
+fn main() {
+	new_channel_struct<Simple>()
+}
+
+pub fn new_channel_struct<T>() GenericChannelStruct {
+	d := GenericChannelStruct{
+		ch: chan T{}
+	}
+	return d
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_method_receiver_type_err.out b/v_windows/v/old/vlib/v/checker/tests/generics_method_receiver_type_err.out
new file mode 100644
index 0000000..1a8b84d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_method_receiver_type_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/generics_method_receiver_type_err.vv:6:11: error: receiver must specify the generic type names, e.g. Foo<T>
+    4 | }
+    5 |
+    6 | pub fn (x Node) str() string {
+      |           ~~~~
+    7 |     return 'Value is : ${u16(x.val)}\nName is : $x.name'
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_method_receiver_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/generics_method_receiver_type_err.vv
new file mode 100644
index 0000000..8a6763c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_method_receiver_type_err.vv
@@ -0,0 +1,16 @@
+struct Node<T> {
+	val  T
+	name string
+}
+
+pub fn (x Node) str() string {
+	return 'Value is : ${u16(x.val)}\nName is : $x.name'
+}
+
+fn main() {
+	xx := Node<u16>{
+		val: u16(11)
+		name: 'man'
+	}
+	println(xx.str())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_non_generic_fn_called_like_a_generic_one.out b/v_windows/v/old/vlib/v/checker/tests/generics_non_generic_fn_called_like_a_generic_one.out
new file mode 100644
index 0000000..0c2c68e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_non_generic_fn_called_like_a_generic_one.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/generics_non_generic_fn_called_like_a_generic_one.vv:4:15: error: a non generic function called like a generic one
+    2 | 
+    3 | fn main() {
+    4 |     x := math.sin<f64>(1.0)
+      |                  ~~~~~
+    5 |     println(x)
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_non_generic_fn_called_like_a_generic_one.vv b/v_windows/v/old/vlib/v/checker/tests/generics_non_generic_fn_called_like_a_generic_one.vv
new file mode 100644
index 0000000..d25ddd1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_non_generic_fn_called_like_a_generic_one.vv
@@ -0,0 +1,6 @@
+import math
+
+fn main() {
+	x := math.sin<f64>(1.0)
+	println(x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_struct_declaration_err.out b/v_windows/v/old/vlib/v/checker/tests/generics_struct_declaration_err.out
new file mode 100644
index 0000000..bd3b2c3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_struct_declaration_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/generics_struct_declaration_err.vv:5:1: error: generic struct declaration must specify the generic type names, e.g. Foo<T>
+    3 | }
+    4 |
+    5 | struct MyGenericChannelStruct {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    6 |     GenericChannelStruct<T>
+    7 |     msg string
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_struct_declaration_err.vv b/v_windows/v/old/vlib/v/checker/tests/generics_struct_declaration_err.vv
new file mode 100644
index 0000000..4828ea3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_struct_declaration_err.vv
@@ -0,0 +1,24 @@
+struct GenericChannelStruct<T> {
+	ch chan T
+}
+
+struct MyGenericChannelStruct {
+	GenericChannelStruct<T>
+	msg string
+}
+
+struct Simple {
+	msg string
+}
+
+fn main() {
+	new_channel_struct<Simple>()
+}
+
+pub fn new_channel_struct<T>() GenericChannelStruct<T> {
+	d := GenericChannelStruct{
+		ch: chan T{}
+	}
+
+	return d
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_struct_init_err.out b/v_windows/v/old/vlib/v/checker/tests/generics_struct_init_err.out
new file mode 100644
index 0000000..c55c336
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_struct_init_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/generics_struct_init_err.vv:58:8: error: generic struct init must specify type parameter, e.g. Foo<int>
+   56 |     ret = holder_call_12(neg, 3)
+   57 |     assert ret == -3
+   58 |     ret = FnHolder1{neg}.call(4)
+      |           ~~~~~~~~~~~~~~
+   59 |     assert ret == -4
+   60 |
+vlib/v/checker/tests/generics_struct_init_err.vv:67:8: error: generic struct init must specify type parameter, e.g. Foo<int>
+   65 |     ret = holder_call_22(neg, 5)
+   66 |     assert ret == -5
+   67 |     ret = FnHolder2{neg}.call(6)
+      |           ~~~~~~~~~~~~~~
+   68 |     assert ret == -6
+   69 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_struct_init_err.vv b/v_windows/v/old/vlib/v/checker/tests/generics_struct_init_err.vv
new file mode 100644
index 0000000..4116799
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_struct_init_err.vv
@@ -0,0 +1,69 @@
+fn neg(a int) int {
+	return -a
+}
+
+struct FnHolder1<T> {
+	func T
+}
+
+fn (self FnHolder1<T>) call(a int) int {
+	return self.func(a)
+}
+
+struct FnHolder2<T> {
+	func fn (int) int
+}
+
+fn (self FnHolder2<T>) call(a int) int {
+	return self.func(a)
+}
+
+fn holder_call_1<T>(func T, a int) int {
+	h := FnHolder1{func}
+	return h.call(a)
+}
+
+fn holder_call_2<T>(func T, a int) int {
+	h := FnHolder2{func}
+	return h.call(a)
+}
+
+fn holder_call_11<T>(func T, a int) int {
+	f := func
+	h := FnHolder1{f}
+	return h.call(a)
+}
+
+fn holder_call_21<T>(func T, a int) int {
+	f := func
+	h := FnHolder2{f}
+	return h.call(a)
+}
+
+fn holder_call_12<T>(func T, a int) int {
+	return FnHolder1{func}.call(a)
+}
+
+fn holder_call_22<T>(func T, a int) int {
+	return FnHolder2{func}.call(a)
+}
+
+fn main() {
+	mut ret := holder_call_1(neg, 1)
+	assert ret == -1
+	ret = holder_call_11(neg, 2)
+	assert ret == -2
+	ret = holder_call_12(neg, 3)
+	assert ret == -3
+	ret = FnHolder1{neg}.call(4)
+	assert ret == -4
+
+	ret = holder_call_2(neg, 3)
+	assert ret == -3
+	ret = holder_call_21(neg, 4)
+	assert ret == -4
+	ret = holder_call_22(neg, 5)
+	assert ret == -5
+	ret = FnHolder2{neg}.call(6)
+	assert ret == -6
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_too_many_parameters.out b/v_windows/v/old/vlib/v/checker/tests/generics_too_many_parameters.out
new file mode 100644
index 0000000..caea12a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_too_many_parameters.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/generics_too_many_parameters.vv:6:8: error: too many generic parameters got 5, expected 1
+    4 | 
+    5 | fn main() {
+    6 |     foo<bool, int, bool, bool, int>(1)
+      |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_too_many_parameters.vv b/v_windows/v/old/vlib/v/checker/tests/generics_too_many_parameters.vv
new file mode 100644
index 0000000..980e1ff
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_too_many_parameters.vv
@@ -0,0 +1,7 @@
+fn foo<T>(b T) {
+    println(b)
+}
+
+fn main() {
+    foo<bool, int, bool, bool, int>(1)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_type_ambiguous.out b/v_windows/v/old/vlib/v/checker/tests/generics_type_ambiguous.out
new file mode 100644
index 0000000..affad87
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_type_ambiguous.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/generics_type_ambiguous.vv:7:19: error: inferred generic type `B` is ambiguous: got `int`, expected `string`
+    5 | 
+    6 | fn main() {
+    7 |   test(2, 2, "2", 2)
+      |                   ^
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/generics_type_ambiguous.vv b/v_windows/v/old/vlib/v/checker/tests/generics_type_ambiguous.vv
new file mode 100644
index 0000000..9eb0f39
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/generics_type_ambiguous.vv
@@ -0,0 +1,8 @@
+fn test<T, B> (a T, b T, c B, d B) {
+    println("$a $b $c $d")
+}
+
+
+fn main() {
+  test(2, 2, "2", 2)
+} 
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/assign_no_value.out b/v_windows/v/old/vlib/v/checker/tests/globals/assign_no_value.out
new file mode 100644
index 0000000..2c3865e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/assign_no_value.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/globals/assign_no_value.vv:1:19: error: undefined ident: `int`
+    1 | __global ( test = int )
+      |                   ~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/assign_no_value.vv b/v_windows/v/old/vlib/v/checker/tests/globals/assign_no_value.vv
new file mode 100644
index 0000000..352847e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/assign_no_value.vv
@@ -0,0 +1 @@
+__global ( test = int )
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/incorrect_name_global.out b/v_windows/v/old/vlib/v/checker/tests/globals/incorrect_name_global.out
new file mode 100644
index 0000000..05d2e26
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/incorrect_name_global.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/globals/incorrect_name_global.vv:1:12: error: global name `A` cannot contain uppercase letters, use snake_case instead
+    1 | __global ( A = int(1) )
+      |            ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/incorrect_name_global.vv b/v_windows/v/old/vlib/v/checker/tests/globals/incorrect_name_global.vv
new file mode 100644
index 0000000..c9550d8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/incorrect_name_global.vv
@@ -0,0 +1 @@
+__global ( A = int(1) )
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/no_type.out b/v_windows/v/old/vlib/v/checker/tests/globals/no_type.out
new file mode 100644
index 0000000..71899d9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/no_type.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/globals/no_type.vv:1:17: error: expecting type declaration
+    1 | __global ( test )
+      |                 ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/no_type.vv b/v_windows/v/old/vlib/v/checker/tests/globals/no_type.vv
new file mode 100644
index 0000000..264ed9d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/no_type.vv
@@ -0,0 +1 @@
+__global ( test )
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/unexpected_eof.out b/v_windows/v/old/vlib/v/checker/tests/globals/unexpected_eof.out
new file mode 100644
index 0000000..f0a6cbc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/unexpected_eof.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/globals/unexpected_eof.vv:3:1: error: unexpected eof, expecting ´)´
+    1 | __global (
+    2 |     x string
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/unexpected_eof.vv b/v_windows/v/old/vlib/v/checker/tests/globals/unexpected_eof.vv
new file mode 100644
index 0000000..ab9c9c6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/unexpected_eof.vv
@@ -0,0 +1,2 @@
+__global (
+	x string
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/unknown_typ.out b/v_windows/v/old/vlib/v/checker/tests/globals/unknown_typ.out
new file mode 100644
index 0000000..60b44bb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/unknown_typ.out
@@ -0,0 +1,11 @@
+vlib/v/checker/tests/globals/unknown_typ.vv:1:12: error: unknown type `foo`
+    1 | __global x foo
+      |            ~~~
+    2 | __global (
+    3 |     y = float(5.0)
+vlib/v/checker/tests/globals/unknown_typ.vv:3:6: error: unknown function: float
+    1 | __global x foo
+    2 | __global (
+    3 |     y = float(5.0)
+      |         ~~~~~~~~~~
+    4 | )
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals/unknown_typ.vv b/v_windows/v/old/vlib/v/checker/tests/globals/unknown_typ.vv
new file mode 100644
index 0000000..9d7fdd1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals/unknown_typ.vv
@@ -0,0 +1,4 @@
+__global x foo
+__global (
+	y = float(5.0)
+)
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals_error.out b/v_windows/v/old/vlib/v/checker/tests/globals_error.out
new file mode 100644
index 0000000..1dcbb36
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals_error.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/globals_error.vv:2:1: error: use `v -enable-globals ...` to enable globals
+    1 |
+    2 | __global ( rfcnt int )
+      | ~~~~~~~~
+    3 |
+    4 | fn abc(){
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals_error.run.out b/v_windows/v/old/vlib/v/checker/tests/globals_error.run.out
new file mode 100644
index 0000000..525f325
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals_error.run.out
@@ -0,0 +1 @@
+rfcnt: 2
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals_error.vv b/v_windows/v/old/vlib/v/checker/tests/globals_error.vv
new file mode 100644
index 0000000..51048dc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals_error.vv
@@ -0,0 +1,12 @@
+
+__global ( rfcnt int )
+
+fn abc(){
+	rfcnt = 2
+}
+
+fn main(){
+	rfcnt = 1
+	abc()
+	println('rfcnt: $rfcnt')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals_run/function_stored_in_global.run.out b/v_windows/v/old/vlib/v/checker/tests/globals_run/function_stored_in_global.run.out
new file mode 100644
index 0000000..586eac7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals_run/function_stored_in_global.run.out
@@ -0,0 +1,4 @@
+[vlib/v/checker/tests/globals_run/function_stored_in_global.vv:14] voidptr(main.abc) == voidptr(cpu_get_id): true
+[vlib/v/checker/tests/globals_run/function_stored_in_global.vv:15] main.cpu_get_id(): 123
+[vlib/v/checker/tests/globals_run/function_stored_in_global.vv:16] abc(): 123
+[vlib/v/checker/tests/globals_run/function_stored_in_global.vv:17] abc() == main.cpu_get_id(): true
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals_run/function_stored_in_global.vv b/v_windows/v/old/vlib/v/checker/tests/globals_run/function_stored_in_global.vv
new file mode 100644
index 0000000..e74825e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals_run/function_stored_in_global.vv
@@ -0,0 +1,20 @@
+__global (
+	cpu_get_id fn () u64
+)
+fn current() u64 {
+	return cpu_get_id()
+}
+
+fn abc() u64 {
+	return 123
+}
+
+fn main() {
+	cpu_get_id = abc
+	dump(voidptr(abc) == voidptr(cpu_get_id))
+	dump(cpu_get_id())
+	dump(abc())
+	dump(abc() == cpu_get_id())
+	assert abc() == cpu_get_id()
+	assert voidptr(abc) == voidptr(cpu_get_id)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.run.out b/v_windows/v/old/vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.run.out
new file mode 100644
index 0000000..7968dd1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.run.out
@@ -0,0 +1,3 @@
+[vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.vv:30] cpu_locals.map(it.x): [123, 456]
+[vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.vv:33] x.x: 123
+[vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.vv:36] y.x: 456
diff --git a/v_windows/v/old/vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.vv b/v_windows/v/old/vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.vv
new file mode 100644
index 0000000..272df4c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/globals_run/global_array_indexed_by_global_fn.vv
@@ -0,0 +1,40 @@
+struct Local {
+	x int
+}
+
+__global (
+	cpu_locals []&Local
+)
+
+__global (
+	cpu_get_id fn () u64
+	cpu_set_id fn (u64)
+)
+
+fn abc0() u64 {
+	return 0
+}
+
+fn abc1() u64 {
+	return 1
+}
+
+pub fn current() &Local {
+	return cpu_locals[cpu_get_id()]
+}
+
+fn main() {
+	cpu_locals = []&Local{}
+	cpu_locals << &Local{123}
+	cpu_locals << &Local{456}
+	dump(cpu_locals.map(it.x))
+	cpu_get_id = abc0
+	x := current()
+	dump(x.x)
+	cpu_get_id = abc1
+	y := current()
+	dump(y.x)
+	assert x != y
+	assert x.x == 123
+	assert y.x == 456
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/go_expr.out b/v_windows/v/old/vlib/v/checker/tests/go_expr.out
new file mode 100644
index 0000000..e19c961
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/go_expr.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/go_expr.vv:2:5: error: expression in `go` must be a function call
+    1 | fn main() {
+    2 |     go 1
+      |        ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/go_expr.vv b/v_windows/v/old/vlib/v/checker/tests/go_expr.vv
new file mode 100644
index 0000000..969b29d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/go_expr.vv
@@ -0,0 +1,3 @@
+fn main() {
+	go 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/go_mut_arg.out b/v_windows/v/old/vlib/v/checker/tests/go_mut_arg.out
new file mode 100644
index 0000000..70271b1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/go_mut_arg.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/go_mut_arg.vv:14:16: error: function in `go` statement cannot contain mutable non-reference arguments 
+   12 |         a: 0
+   13 |     }
+   14 |     go change(mut x)
+      |                   ^
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/go_mut_arg.vv b/v_windows/v/old/vlib/v/checker/tests/go_mut_arg.vv
new file mode 100644
index 0000000..af86f15
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/go_mut_arg.vv
@@ -0,0 +1,15 @@
+struct St {
+mut:
+	a int
+}
+
+fn change(mut a St) {
+	a.a++
+}
+
+fn main() {
+	mut x := St{
+		a: 0
+	}
+	go change(mut x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/go_mut_receiver.out b/v_windows/v/old/vlib/v/checker/tests/go_mut_receiver.out
new file mode 100644
index 0000000..f8b2681
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/go_mut_receiver.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/go_mut_receiver.vv:14:5: error: method in `go` statement cannot have non-reference mutable receiver 
+   12 |         a: 0
+   13 |     }
+   14 |     go x.change()
+      |        ^
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/go_mut_receiver.vv b/v_windows/v/old/vlib/v/checker/tests/go_mut_receiver.vv
new file mode 100644
index 0000000..0b64d51
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/go_mut_receiver.vv
@@ -0,0 +1,15 @@
+struct St {
+mut:
+	a int
+}
+
+fn (mut a St) change() {
+	a.a++
+}
+
+fn main() {
+	mut x := St{
+		a: 0
+	}
+	go x.change()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/go_wait_or.out b/v_windows/v/old/vlib/v/checker/tests/go_wait_or.out
new file mode 100644
index 0000000..146f4fb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/go_wait_or.out
@@ -0,0 +1,69 @@
+vlib/v/checker/tests/go_wait_or.vv:11:17: error: unexpected `?`, the function `wait` does not return an optional
+    9 |         go d(1)
+   10 |     ]
+   11 |     r := tg.wait() ?
+      |                    ^
+   12 |     println(r)
+   13 |     s := tg[0].wait() or { panic('problem') }
+vlib/v/checker/tests/go_wait_or.vv:13:20: error: unexpected `or` block, the function `wait` does not return an optional
+   11 |     r := tg.wait() ?
+   12 |     println(r)
+   13 |     s := tg[0].wait() or { panic('problem') }
+      |                       ~~~~~~~~~~~~~~~~~~~~~~~
+   14 |     println(s)
+   15 |     tg2 := [
+vlib/v/checker/tests/go_wait_or.vv:19:13: error: unexpected `or` block, the function `wait` does not return an optional
+   17 |         go e(1)
+   18 |     ]
+   19 |     tg2.wait() or { panic('problem') }
+      |                ~~~~~~~~~~~~~~~~~~~~~~~
+   20 |     tg2[0].wait() ?
+   21 |     tg3 := [
+vlib/v/checker/tests/go_wait_or.vv:20:16: error: unexpected `?`, the function `wait` does not return an optional
+   18 |     ]
+   19 |     tg2.wait() or { panic('problem') }
+   20 |     tg2[0].wait() ?
+      |                   ^
+   21 |     tg3 := [
+   22 |         go f(0)
+vlib/v/checker/tests/go_wait_or.vv:25:6: error: `.wait()` cannot be called for an array when thread functions return optionals. Iterate over the arrays elements instead and handle each returned optional with `or`.
+   23 |         go f(1)
+   24 |     ]
+   25 |     tg3.wait() or { panic('problem') }
+      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   26 |     for t in tg3 {
+   27 |         a := t.wait()
+vlib/v/checker/tests/go_wait_or.vv:27:10: error: wait() returns an option, so it should have either an `or {}` block, or `?` at the end
+   25 |     tg3.wait() or { panic('problem') }
+   26 |     for t in tg3 {
+   27 |         a := t.wait()
+      |                ~~~~~~
+   28 |         println(a)
+   29 |     }
+vlib/v/checker/tests/go_wait_or.vv:31:15: error: wait() returns an option, so it should have either an `or {}` block, or `?` at the end
+   29 |     }
+   30 |     for i, _ in tg3 {
+   31 |         a := tg3[i].wait()
+      |                     ~~~~~~
+   32 |         println(a)
+   33 |     }
+vlib/v/checker/tests/go_wait_or.vv:38:6: error: `.wait()` cannot be called for an array when thread functions return optionals. Iterate over the arrays elements instead and handle each returned optional with `or`.
+   36 |         go g(1)
+   37 |     ]
+   38 |     tg4.wait()
+      |         ~~~~~~
+   39 |     tg4[0].wait()
+   40 |     go g(3) or { panic('problem') }
+vlib/v/checker/tests/go_wait_or.vv:39:9: error: wait() returns an option, so it should have either an `or {}` block, or `?` at the end
+   37 |     ]
+   38 |     tg4.wait()
+   39 |     tg4[0].wait()
+      |            ~~~~~~
+   40 |     go g(3) or { panic('problem') }
+   41 | }
+vlib/v/checker/tests/go_wait_or.vv:40:10: error: optional handling cannot be done in `go` call. Do it when calling `.wait()`
+   38 |     tg4.wait()
+   39 |     tg4[0].wait()
+   40 |     go g(3) or { panic('problem') }
+      |             ~~~~~~~~~~~~~~~~~~~~~~~
+   41 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/go_wait_or.vv b/v_windows/v/old/vlib/v/checker/tests/go_wait_or.vv
new file mode 100644
index 0000000..3522f90
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/go_wait_or.vv
@@ -0,0 +1,41 @@
+fn d(n int) f64 { return f64(n) }
+fn e(n int) { }
+fn f(n int) ?f64 { return f64(n) }
+fn g(n int) ? { }
+
+fn main() {
+	tg := [
+		go d(0)
+		go d(1)
+	]
+	r := tg.wait() ?
+	println(r)
+	s := tg[0].wait() or { panic('problem') }
+	println(s)
+	tg2 := [
+		go e(0)
+		go e(1)
+	]
+	tg2.wait() or { panic('problem') }
+	tg2[0].wait() ?
+	tg3 := [
+		go f(0)
+		go f(1)
+	]
+	tg3.wait() or { panic('problem') }
+	for t in tg3 {
+		a := t.wait()
+		println(a)
+	}
+	for i, _ in tg3 {
+		a := tg3[i].wait()
+		println(a)
+	}
+	tg4 := [
+		go g(0)
+		go g(1)
+	]
+	tg4.wait()
+	tg4[0].wait()
+	go g(3) or { panic('problem') }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/goto_label.out b/v_windows/v/old/vlib/v/checker/tests/goto_label.out
new file mode 100644
index 0000000..9312085
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/goto_label.out
@@ -0,0 +1,63 @@
+vlib/v/checker/tests/goto_label.vv:5:7: error: unknown label `a1`
+    3 |     goto f2
+    4 |     f1:
+    5 |     goto a1
+      |          ~~
+    6 |     _ = fn(){
+    7 |         goto f1
+vlib/v/checker/tests/goto_label.vv:7:8: error: unknown label `f1`
+    5 |     goto a1
+    6 |     _ = fn(){
+    7 |         goto f1
+      |              ~~
+    8 |         goto f2
+    9 |         goto a1
+vlib/v/checker/tests/goto_label.vv:8:8: error: unknown label `f2`
+    6 |     _ = fn(){
+    7 |         goto f1
+    8 |         goto f2
+      |              ~~
+    9 |         goto a1
+   10 |         a1:
+vlib/v/checker/tests/goto_label.vv:9:8: error: `goto` requires `unsafe` (consider using labelled break/continue)
+    7 |         goto f1
+    8 |         goto f2
+    9 |         goto a1
+      |              ~~
+   10 |         a1:
+   11 |         goto a1
+vlib/v/checker/tests/goto_label.vv:11:8: error: `goto` requires `unsafe` (consider using labelled break/continue)
+    9 |         goto a1
+   10 |         a1:
+   11 |         goto a1
+      |              ~~
+   12 |     }
+   13 |     f2:
+vlib/v/checker/tests/goto_label.vv:14:7: error: unknown label `a1`
+   12 |     }
+   13 |     f2:
+   14 |     goto a1
+      |          ~~
+   15 |     goto f1 // back
+   16 |     goto f2
+vlib/v/checker/tests/goto_label.vv:22:7: error: unknown label `f1`
+   20 |     goto g1 // forward
+   21 |     g1:
+   22 |     goto f1
+      |          ~~
+   23 |     goto a1
+   24 |     goto g1 // back
+vlib/v/checker/tests/goto_label.vv:23:7: error: unknown label `a1`
+   21 |     g1:
+   22 |     goto f1
+   23 |     goto a1
+      |          ~~
+   24 |     goto g1 // back
+   25 |     goto undefined
+vlib/v/checker/tests/goto_label.vv:25:7: error: unknown label `undefined`
+   23 |     goto a1
+   24 |     goto g1 // back
+   25 |     goto undefined
+      |          ~~~~~~~~~
+   26 | }}
+   27 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/goto_label.vv b/v_windows/v/old/vlib/v/checker/tests/goto_label.vv
new file mode 100644
index 0000000..23b2cd7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/goto_label.vv
@@ -0,0 +1,33 @@
+fn f() {unsafe {
+	goto f1 // forward
+	goto f2
+	f1:
+	goto a1
+	_ = fn(){
+		goto f1
+		goto f2
+		goto a1
+		a1:
+		goto a1
+	}
+	f2:
+	goto a1
+	goto f1 // back
+	goto f2
+}}
+
+fn g() {unsafe {
+	goto g1 // forward
+	g1:
+	goto f1
+	goto a1
+	goto g1 // back
+	goto undefined
+}}
+
+// implicit main
+unsafe {
+	goto m1
+	m1:
+	goto m1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/hex_lit_without_digit_err.out b/v_windows/v/old/vlib/v/checker/tests/hex_lit_without_digit_err.out
new file mode 100644
index 0000000..f6407ba
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/hex_lit_without_digit_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/hex_lit_without_digit_err.vv:2:14: error: number part of this hexadecimal is not provided
+    1 | fn main() {
+    2 |     println(0x)
+      |              ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/hex_lit_without_digit_err.vv b/v_windows/v/old/vlib/v/checker/tests/hex_lit_without_digit_err.vv
new file mode 100644
index 0000000..7063035
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/hex_lit_without_digit_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(0x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/hex_lit_wrong_digit_err.out b/v_windows/v/old/vlib/v/checker/tests/hex_lit_wrong_digit_err.out
new file mode 100644
index 0000000..16ebb52
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/hex_lit_wrong_digit_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/hex_lit_wrong_digit_err.vv:2:18: error: this hexadecimal number has unsuitable digit `g`
+    1 | fn main() {
+    2 |     println(0x111ghi)
+      |                  ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/hex_lit_wrong_digit_err.vv b/v_windows/v/old/vlib/v/checker/tests/hex_lit_wrong_digit_err.vv
new file mode 100644
index 0000000..1b7b07d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/hex_lit_wrong_digit_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(0x111ghi)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/hex_literal_overflow.out b/v_windows/v/old/vlib/v/checker/tests/hex_literal_overflow.out
new file mode 100644
index 0000000..9475150
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/hex_literal_overflow.out
@@ -0,0 +1,18 @@
+vlib/v/checker/tests/hex_literal_overflow.vv:1:7: error: hex character literal overflows string
+    1 | a := '\x11ffff'
+      |       ~~~~~~~~
+    2 | b := '\x20ffff'
+    3 | c := '\x10fffff'
+vlib/v/checker/tests/hex_literal_overflow.vv:2:7: error: hex character literal overflows string
+    1 | a := '\x11ffff'
+    2 | b := '\x20ffff'
+      |       ~~~~~~~~
+    3 | c := '\x10fffff'
+    4 | println(a)
+vlib/v/checker/tests/hex_literal_overflow.vv:3:7: error: hex character literal overflows string
+    1 | a := '\x11ffff'
+    2 | b := '\x20ffff'
+    3 | c := '\x10fffff'
+      |       ~~~~~~~~~
+    4 | println(a)
+    5 | println(b)
diff --git a/v_windows/v/old/vlib/v/checker/tests/hex_literal_overflow.vv b/v_windows/v/old/vlib/v/checker/tests/hex_literal_overflow.vv
new file mode 100644
index 0000000..60903f8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/hex_literal_overflow.vv
@@ -0,0 +1,6 @@
+a := '\x11ffff'
+b := '\x20ffff'
+c := '\x10fffff'
+println(a)
+println(b)
+println(c)
diff --git a/v_windows/v/old/vlib/v/checker/tests/ierror_in_return_tuple.out b/v_windows/v/old/vlib/v/checker/tests/ierror_in_return_tuple.out
new file mode 100644
index 0000000..60d6483
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ierror_in_return_tuple.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/ierror_in_return_tuple.vv:1:29: error: type `IError` cannot be used in multi-return, return an option instead
+    1 | fn return_ierror_in_tuple() (bool, IError) {
+      |                             ~~~~~~~~~~~~~~
+    2 |     return false, error('')
+    3 | }
+vlib/v/checker/tests/ierror_in_return_tuple.vv:5:29: error: option cannot be used in multi-return, return an option instead
+    3 | }
+    4 | 
+    5 | fn return_option_in_tuple() (bool, ?bool) {
+      |                             ~~~~~~~~~~~~~
+    6 |     return false, error('')
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/ierror_in_return_tuple.vv b/v_windows/v/old/vlib/v/checker/tests/ierror_in_return_tuple.vv
new file mode 100644
index 0000000..4717528
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ierror_in_return_tuple.vv
@@ -0,0 +1,7 @@
+fn return_ierror_in_tuple() (bool, IError) {
+	return false, error('')
+}
+
+fn return_option_in_tuple() (bool, ?bool) {
+	return false, error('')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_expr_last_stmt.out b/v_windows/v/old/vlib/v/checker/tests/if_expr_last_stmt.out
new file mode 100644
index 0000000..2fdeabc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_expr_last_stmt.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/if_expr_last_stmt.vv:4:7: error: `if` expression requires an expression as the last statement of every branch
+    2 |     _ = if true {
+    3 |         1
+    4 |     } else if false {
+      |       ~~~~~~~~~~~~~
+    5 |     } else {
+    6 |     }
+vlib/v/checker/tests/if_expr_last_stmt.vv:5:7: error: `if` expression requires an expression as the last statement of every branch
+    3 |         1
+    4 |     } else if false {
+    5 |     } else {
+      |       ~~~~
+    6 |     }
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_expr_last_stmt.vv b/v_windows/v/old/vlib/v/checker/tests/if_expr_last_stmt.vv
new file mode 100644
index 0000000..eb5dd0c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_expr_last_stmt.vv
@@ -0,0 +1,7 @@
+fn main() {
+    _ = if true {
+        1
+    } else if false {
+    } else {
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_expr_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/if_expr_mismatch.out
new file mode 100644
index 0000000..0c45b88
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_expr_mismatch.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/if_expr_mismatch.vv:2:7: error: mismatched types `string` and `int literal`
+    1 | fn main() {
+    2 |     s := if true { '12' } else { 12 }
+      |          ~~
+    3 |     println(s)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_expr_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/if_expr_mismatch.vv
new file mode 100644
index 0000000..597135b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_expr_mismatch.vv
@@ -0,0 +1,4 @@
+fn main() {
+	s := if true { '12' } else { 12 }
+	println(s)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_expr_no_else.out b/v_windows/v/old/vlib/v/checker/tests/if_expr_no_else.out
new file mode 100644
index 0000000..87fb3e7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_expr_no_else.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/if_expr_no_else.vv:2:9: error: `if` expression needs `else` clause
+    1 | fn main() {
+    2 |     _ = if true { 1 }
+      |         ~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_expr_no_else.vv b/v_windows/v/old/vlib/v/checker/tests/if_expr_no_else.vv
new file mode 100644
index 0000000..d416cc9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_expr_no_else.vv
@@ -0,0 +1,3 @@
+fn main() {
+    _ = if true { 1 }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_expr_optional_err.out b/v_windows/v/old/vlib/v/checker/tests/if_expr_optional_err.out
new file mode 100644
index 0000000..9adbc4a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_expr_optional_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/if_expr_optional_err.vv:7:5: error: non-bool type `?bool` used as if condition
+    5 | fn main() {
+    6 | 
+    7 |     if get_bool() {
+      |        ~~~~~~~~~~
+    8 |         println("Using plain lists")
+    9 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_expr_optional_err.vv b/v_windows/v/old/vlib/v/checker/tests/if_expr_optional_err.vv
new file mode 100644
index 0000000..88d617d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_expr_optional_err.vv
@@ -0,0 +1,10 @@
+fn get_bool() ?bool {
+	return true
+}
+
+fn main() {
+
+	if get_bool() {
+		println("Using plain lists")
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_match_expr.out b/v_windows/v/old/vlib/v/checker/tests/if_match_expr.out
new file mode 100644
index 0000000..9c65976
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_match_expr.out
@@ -0,0 +1,49 @@
+vlib/v/checker/tests/if_match_expr.vv:8:6: error: `if` expression branch has unsupported statement (`v.ast.ForStmt`)
+    6 |     if true {1} else {-1} // result
+    7 | } else {
+    8 |     for {break}
+      |         ^
+    9 |     {}
+   10 |     match true {true {} else {}} // statement not expression
+vlib/v/checker/tests/if_match_expr.vv:9:2: error: `if` expression branch has unsupported statement (`v.ast.Block`)
+    7 | } else {
+    8 |     for {break}
+    9 |     {}
+      |     ^
+   10 |     match true {true {} else {}} // statement not expression
+   11 |     _ = match true {true {1} else {-1}} // OK
+vlib/v/checker/tests/if_match_expr.vv:10:2: error: `if` expression branch has unsupported statement (`v.ast.MatchExpr`)
+    8 |     for {break}
+    9 |     {}
+   10 |     match true {true {} else {}} // statement not expression
+      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   11 |     _ = match true {true {1} else {-1}} // OK
+   12 |     match true {true {1} else {-1}} // result
+vlib/v/checker/tests/if_match_expr.vv:17:3: error: `match` expression branch has unsupported statement (`v.ast.IfExpr`)
+   15 | _ = match true {
+   16 |     true {
+   17 |         if true {} // statement not expression
+      |         ~~
+   18 |         _ = if true {1} else {-1} // OK
+   19 |         if true {1} else {-1} // result
+vlib/v/checker/tests/if_match_expr.vv:22:10: error: `match` expression branch has unsupported statement (`v.ast.AssertStmt`)
+   20 |     }
+   21 |     else {
+   22 |         assert true
+      |                ~~~~
+   23 |         match true {true {} else {}} // statement not expression
+   24 |         _ = match true {true {1} else {-1}} // OK
+vlib/v/checker/tests/if_match_expr.vv:23:3: error: `match` expression branch has unsupported statement (`v.ast.MatchExpr`)
+   21 |     else {
+   22 |         assert true
+   23 |         match true {true {} else {}} // statement not expression
+      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   24 |         _ = match true {true {1} else {-1}} // OK
+   25 |         match true {true {1} else {-1}} // result
+vlib/v/checker/tests/if_match_expr.vv:25:3: error: return type mismatch, it should be `int`
+   23 |         match true {true {} else {}} // statement not expression
+   24 |         _ = match true {true {1} else {-1}} // OK
+   25 |         match true {true {1} else {-1}} // result
+      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   26 |     }
+   27 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_match_expr.vv b/v_windows/v/old/vlib/v/checker/tests/if_match_expr.vv
new file mode 100644
index 0000000..655f25a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_match_expr.vv
@@ -0,0 +1,27 @@
+// only C expressions are allowed for each statement
+
+_ = if true {
+	if true {} // FIXME should error, if statement
+	_ = if true {1} else {-1} // OK
+	if true {1} else {-1} // result
+} else {
+	for {break}
+	{}
+	match true {true {} else {}} // statement not expression
+	_ = match true {true {1} else {-1}} // OK
+	match true {true {1} else {-1}} // result
+}
+
+_ = match true {
+	true {
+		if true {} // statement not expression
+		_ = if true {1} else {-1} // OK
+		if true {1} else {-1} // result
+	}
+	else {
+		assert true
+		match true {true {} else {}} // statement not expression
+		_ = match true {true {1} else {-1}} // OK
+		match true {true {1} else {-1}} // result
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_match_expr_err.out b/v_windows/v/old/vlib/v/checker/tests/if_match_expr_err.out
new file mode 100644
index 0000000..2c16775
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_match_expr_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/if_match_expr_err.vv:3:8: error: cannot use `match` with `if` statements
+    1 | fn main() {
+    2 |     a := 0
+    3 |     if match a {
+      |        ~~~~~
+    4 |         0 {
+    5 |             println('a is zero')
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_match_expr_err.vv b/v_windows/v/old/vlib/v/checker/tests/if_match_expr_err.vv
new file mode 100644
index 0000000..511bbc7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_match_expr_err.vv
@@ -0,0 +1,13 @@
+fn main() {
+    a := 0
+    if match a {
+        0 {
+            println('a is zero')
+        }
+        else {
+            println('unreachable branch')
+        }
+    } 5 < 7 {
+        println('5 is less than 7')
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_match_result.out b/v_windows/v/old/vlib/v/checker/tests/if_match_result.out
new file mode 100644
index 0000000..53a154e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_match_result.out
@@ -0,0 +1,34 @@
+vlib/v/checker/tests/if_match_result.vv:2:3: error: assignment mismatch: 1 variable(s) 0 value(s)
+    1 | // missing results
+    2 | _ = match 4 {
+      |   ^
+    3 |     1 {}
+    4 |     else {}
+vlib/v/checker/tests/if_match_result.vv:6:5: error: `if` expression requires an expression as the last statement of every branch
+    4 |     else {}
+    5 | }
+    6 | _ = if true {
+      |     ~~~~~~~
+    7 | } else {
+    8 | }
+vlib/v/checker/tests/if_match_result.vv:7:3: error: `if` expression requires an expression as the last statement of every branch
+    5 | }
+    6 | _ = if true {
+    7 | } else {
+      |   ~~~~
+    8 | }
+    9 |
+vlib/v/checker/tests/if_match_result.vv:11:3: error: assignment mismatch: 1 variable(s) 0 value(s)
+    9 |
+   10 | // void results
+   11 | _ = match 4 {
+      |   ^
+   12 |     1 {println('')}
+   13 |     else {exit(0)}
+vlib/v/checker/tests/if_match_result.vv:15:3: error: assignment mismatch: 1 variable(s) 0 value(s)
+   13 |     else {exit(0)}
+   14 | }
+   15 | _ = if true {
+      |   ^
+   16 |     println('')
+   17 | } else {
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_match_result.vv b/v_windows/v/old/vlib/v/checker/tests/if_match_result.vv
new file mode 100644
index 0000000..ad85b13
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_match_result.vv
@@ -0,0 +1,19 @@
+// missing results
+_ = match 4 {
+	1 {}
+	else {}
+}
+_ = if true {
+} else {
+}
+
+// void results
+_ = match 4 {
+	1 {println('')}
+	else {exit(0)}
+}
+_ = if true {
+	println('')
+} else {
+	exit(0)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_non_bool_cond.out b/v_windows/v/old/vlib/v/checker/tests/if_non_bool_cond.out
new file mode 100644
index 0000000..08c9765
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_non_bool_cond.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/if_non_bool_cond.vv:2:5: error: non-bool type `string` used as if condition
+    1 | fn main() {
+    2 |     if '10' {
+      |        ~~~~
+    3 |         println('10')
+    4 |     }
+vlib/v/checker/tests/if_non_bool_cond.vv:6:5: error: non-bool type `int literal` used as if condition
+    4 |     }
+    5 | 
+    6 |     if 5 {
+      |        ^
+    7 |         println(5)
+    8 |     }
+vlib/v/checker/tests/if_non_bool_cond.vv:10:5: error: non-bool type `void` used as if condition
+    8 |     }
+    9 | 
+   10 |     if println('v') {
+      |        ~~~~~~~~~~~~
+   11 |         println('println')
+   12 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/if_non_bool_cond.vv b/v_windows/v/old/vlib/v/checker/tests/if_non_bool_cond.vv
new file mode 100644
index 0000000..626aafe
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/if_non_bool_cond.vv
@@ -0,0 +1,13 @@
+fn main() {
+	if '10' {
+		println('10')
+	}
+
+	if 5 {
+		println(5)
+	}
+
+	if println('v') {
+		println('println')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_arg.out b/v_windows/v/old/vlib/v/checker/tests/immutable_arg.out
new file mode 100644
index 0000000..6f46625
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_arg.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/immutable_arg.vv:13:8: error: `a` is immutable, declare it with `mut` to make it mutable 
+   11 | fn main() {
+   12 |     a := St{e: 2}
+   13 |     f(mut a)
+      |           ^
+   14 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_arg.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_arg.vv
new file mode 100644
index 0000000..08e799d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_arg.vv
@@ -0,0 +1,14 @@
+struct St {
+mut:
+	e int
+}
+
+fn f(mut x St) {
+	x.e++
+	println(x)
+}
+
+fn main() {
+	a := St{e: 2}
+	f(mut a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_assign.out b/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_assign.out
new file mode 100644
index 0000000..b091e67
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_assign.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/immutable_array_field_assign.vv:9:4: error: field `i` of struct `Aaa` is immutable
+    7 |         i: [0]
+    8 |     }
+    9 |     a.i[0] = 3
+      |       ^
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_assign.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_assign.vv
new file mode 100644
index 0000000..adadfd6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_assign.vv
@@ -0,0 +1,10 @@
+struct Aaa {
+	i []int
+}
+
+fn main() {
+	mut a := Aaa{
+		i: [0]
+	}
+	a.i[0] = 3
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_shift.out b/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_shift.out
new file mode 100644
index 0000000..ec34ee2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_shift.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/immutable_array_field_shift.vv:14:4: error: field `a` of struct `Bbb` is immutable
+   12 |         a: Aaa{}
+   13 |     }
+   14 |     b.a.i << 3
+      |       ^
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_shift.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_shift.vv
new file mode 100644
index 0000000..f04054b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_field_shift.vv
@@ -0,0 +1,15 @@
+struct Aaa {
+mut:
+	i []int
+}
+
+struct Bbb {
+	a Aaa
+}
+
+fn main() {
+	mut b := Bbb{
+		a: Aaa{}
+	}
+	b.a.i << 3
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_assign.out b/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_assign.out
new file mode 100644
index 0000000..3675fe2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_assign.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/immutable_array_struct_assign.vv:8:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    6 | fn main() {
+    7 |     a := Aaa{}
+    8 |     a.i[0] += 3
+      |     ^
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_assign.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_assign.vv
new file mode 100644
index 0000000..b150d9d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_assign.vv
@@ -0,0 +1,9 @@
+struct Aaa {
+pub mut:
+	i []int
+}
+
+fn main() {
+	a := Aaa{}
+	a.i[0] += 3
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_shift.out b/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_shift.out
new file mode 100644
index 0000000..b9a25fc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_shift.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/immutable_array_struct_shift.vv:8:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    6 | fn main() {
+    7 |     a := []Aaa{}
+    8 |     a[0].i << 3
+      |     ^
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_shift.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_shift.vv
new file mode 100644
index 0000000..89e4d6c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_struct_shift.vv
@@ -0,0 +1,9 @@
+struct Aaa {
+pub mut:
+	i []int
+}
+
+fn main() {
+	a := []Aaa{}
+	a[0].i << 3
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_var.out b/v_windows/v/old/vlib/v/checker/tests/immutable_array_var.out
new file mode 100644
index 0000000..6e45b41
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_var.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/immutable_array_var.vv:3:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    1 | fn main() {
+    2 |     a := [1, 2]
+    3 |     a << 3
+      |     ^
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_array_var.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_array_var.vv
new file mode 100644
index 0000000..1afa343
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_array_var.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a := [1, 2]
+	a << 3
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_builtin_modify.out b/v_windows/v/old/vlib/v/checker/tests/immutable_builtin_modify.out
new file mode 100644
index 0000000..059e3bc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_builtin_modify.out
@@ -0,0 +1,11 @@
+vlib/v/checker/tests/immutable_builtin_modify.vv:2:3: error: `string` can not be modified
+    1 | s := ''
+    2 | s.len = 123
+      |   ~~~
+    3 | //
+    4 | b := []byte{}
+vlib/v/checker/tests/immutable_builtin_modify.vv:5:3: error: `array` can not be modified
+    3 | //
+    4 | b := []byte{}
+    5 | b.len = 34
+      |   ~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_builtin_modify.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_builtin_modify.vv
new file mode 100644
index 0000000..e6cb706
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_builtin_modify.vv
@@ -0,0 +1,5 @@
+s := ''
+s.len = 123
+//
+b := []byte{}
+b.len = 34
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_field.out b/v_windows/v/old/vlib/v/checker/tests/immutable_field.out
new file mode 100644
index 0000000..05b6214
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_field.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/immutable_field.vv:8:4: error: field `i1` of struct `Aaa` is immutable
+    6 | fn main() {
+    7 |     a := Aaa{1}
+    8 |     a.i1 = 2
+      |       ~~
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_field.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_field.vv
new file mode 100644
index 0000000..487d913
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_field.vv
@@ -0,0 +1,9 @@
+struct Aaa {
+pub:
+	i1 int
+}
+
+fn main() {
+	a := Aaa{1}
+	a.i1 = 2
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_field_postfix.out b/v_windows/v/old/vlib/v/checker/tests/immutable_field_postfix.out
new file mode 100644
index 0000000..fb2c4d8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_field_postfix.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/immutable_field_postfix.vv:7:4: error: field `i` of struct `Aaa` is immutable
+    5 | fn main() {
+    6 |     mut a := Aaa{}
+    7 |     a.i++
+      |       ^
+    8 |     a.i--
+    9 | }
+vlib/v/checker/tests/immutable_field_postfix.vv:8:4: error: field `i` of struct `Aaa` is immutable
+    6 |     mut a := Aaa{}
+    7 |     a.i++
+    8 |     a.i--
+      |       ^
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_field_postfix.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_field_postfix.vv
new file mode 100644
index 0000000..0689c70
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_field_postfix.vv
@@ -0,0 +1,9 @@
+struct Aaa {
+	i int
+}
+
+fn main() {
+	mut a := Aaa{}
+	a.i++
+	a.i--
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_interface_field.out b/v_windows/v/old/vlib/v/checker/tests/immutable_interface_field.out
new file mode 100644
index 0000000..0e421af
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_interface_field.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/immutable_interface_field.vv:10:4: error: field `i1` of interface `&Bbb` is immutable
+    8 | 
+    9 | fn mutate_interface(mut b Bbb) {
+   10 |     b.i1 = 2
+      |       ~~
+   11 | }
+   12 |
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_interface_field.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_interface_field.vv
new file mode 100644
index 0000000..c3aabef
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_interface_field.vv
@@ -0,0 +1,16 @@
+struct Aaa {
+	i1 int
+}
+
+interface Bbb {
+	i1 int
+}
+
+fn mutate_interface(mut b Bbb) {
+	b.i1 = 2
+}
+
+fn main() {
+	mut a := Aaa{1}
+	mutate_interface(mut a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_map.out b/v_windows/v/old/vlib/v/checker/tests/immutable_map.out
new file mode 100644
index 0000000..3c5f7e3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_map.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/immutable_map.vv:3:2: error: `m` is immutable, declare it with `mut` to make it mutable
+    1 | fn main() {
+    2 |     m := map[string]int
+    3 |     m['test']++
+      |     ^
+    4 |     m['test']--
+    5 |     _ = m.move()
+vlib/v/checker/tests/immutable_map.vv:4:2: error: `m` is immutable, declare it with `mut` to make it mutable
+    2 |     m := map[string]int
+    3 |     m['test']++
+    4 |     m['test']--
+      |     ^
+    5 |     _ = m.move()
+    6 |     m.delete('s')
+vlib/v/checker/tests/immutable_map.vv:5:6: error: `m` is immutable, declare it with `mut` to make it mutable
+    3 |     m['test']++
+    4 |     m['test']--
+    5 |     _ = m.move()
+      |         ^
+    6 |     m.delete('s')
+    7 | }
+vlib/v/checker/tests/immutable_map.vv:6:2: error: `m` is immutable, declare it with `mut` to make it mutable
+    4 |     m['test']--
+    5 |     _ = m.move()
+    6 |     m.delete('s')
+      |     ^
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_map.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_map.vv
new file mode 100644
index 0000000..f3e0008
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_map.vv
@@ -0,0 +1,7 @@
+fn main() {
+	m := map[string]int
+	m['test']++
+	m['test']--
+	_ = m.move()
+	m.delete('s')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_rec.out b/v_windows/v/old/vlib/v/checker/tests/immutable_rec.out
new file mode 100644
index 0000000..4c76ed4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_rec.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/immutable_rec.vv:13:2: error: `a` is immutable, declare it with `mut` to make it mutable 
+   11 | fn main() {
+   12 |     a := St{e: 2}
+   13 |     a.f()
+      |     ^
+   14 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_rec.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_rec.vv
new file mode 100644
index 0000000..acbc007
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_rec.vv
@@ -0,0 +1,14 @@
+struct St {
+mut:
+	e int
+}
+
+fn (mut x St) f() {
+	x.e++
+	println(x)
+}
+
+fn main() {
+	a := St{e: 2}
+	a.f()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_struct_postfix.out b/v_windows/v/old/vlib/v/checker/tests/immutable_struct_postfix.out
new file mode 100644
index 0000000..86c87c2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_struct_postfix.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/immutable_struct_postfix.vv:8:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    6 | fn main() {
+    7 |     a := Aaa{}
+    8 |     a.i++
+      |     ^
+    9 |     a.i--
+   10 | }
+vlib/v/checker/tests/immutable_struct_postfix.vv:9:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    7 |     a := Aaa{}
+    8 |     a.i++
+    9 |     a.i--
+      |     ^
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_struct_postfix.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_struct_postfix.vv
new file mode 100644
index 0000000..dbd3e78
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_struct_postfix.vv
@@ -0,0 +1,10 @@
+struct Aaa {
+mut:
+	i int
+}
+
+fn main() {
+	a := Aaa{}
+	a.i++
+	a.i--
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_var.out b/v_windows/v/old/vlib/v/checker/tests/immutable_var.out
new file mode 100644
index 0000000..012ef94
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_var.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/immutable_var.vv:3:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    1 | fn main() {
+    2 |     a := 1
+    3 |     a = 2
+      |     ^
+    4 |     _ = a
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_var.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_var.vv
new file mode 100644
index 0000000..aeeaef1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_var.vv
@@ -0,0 +1,5 @@
+fn main() {
+	a := 1
+	a = 2
+	_ = a
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_var_postfix.out b/v_windows/v/old/vlib/v/checker/tests/immutable_var_postfix.out
new file mode 100644
index 0000000..ca05696
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_var_postfix.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/immutable_var_postfix.vv:3:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    1 | fn main() {
+    2 |     a := 1
+    3 |     a++
+      |     ^
+    4 |     a--
+    5 | }
+vlib/v/checker/tests/immutable_var_postfix.vv:4:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    2 |     a := 1
+    3 |     a++
+    4 |     a--
+      |     ^
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/immutable_var_postfix.vv b/v_windows/v/old/vlib/v/checker/tests/immutable_var_postfix.vv
new file mode 100644
index 0000000..ff1e94d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/immutable_var_postfix.vv
@@ -0,0 +1,5 @@
+fn main() {
+	a := 1
+	a++
+	a--
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_duplicate_err.out b/v_windows/v/old/vlib/v/checker/tests/import_duplicate_err.out
new file mode 100644
index 0000000..3c04980
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_duplicate_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/import_duplicate_err.vv:2:8: error: `time` was already imported on line 1
+    1 | import time
+    2 | import time
+      |        ~~~~
+    3 | fn main() {
+    4 |     println(time.now().unix_time())
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_duplicate_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_duplicate_err.vv
new file mode 100644
index 0000000..f0f7d8d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_duplicate_err.vv
@@ -0,0 +1,5 @@
+import time
+import time
+fn main() {
+	println(time.now().unix_time())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_middle_err.out b/v_windows/v/old/vlib/v/checker/tests/import_middle_err.out
new file mode 100644
index 0000000..81c6639
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_middle_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/import_middle_err.vv:5:1: error: `import x` can only be declared at the beginning of the file
+    3 |     println('hello, world')
+    4 | }
+    5 | import os
+      | ~~~~~~
+    6 | fn main() {
+    7 |     println(time.now())
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_middle_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_middle_err.vv
new file mode 100644
index 0000000..f38e462
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_middle_err.vv
@@ -0,0 +1,8 @@
+import time
+fn show() {
+	println('hello, world')
+}
+import os
+fn main() {
+	println(time.now())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_mod_as_mod_err.out b/v_windows/v/old/vlib/v/checker/tests/import_mod_as_mod_err.out
new file mode 100644
index 0000000..5a5315b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_mod_as_mod_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/import_mod_as_mod_err.vv:1:16: error: import alias `math as math` is redundant
+    1 | import math as math
+      |                ~~~~
+    2 |
+    3 | fn main() {
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_mod_as_mod_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_mod_as_mod_err.vv
new file mode 100644
index 0000000..2a12534
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_mod_as_mod_err.vv
@@ -0,0 +1,5 @@
+import math as math
+
+fn main() {
+    println(math.e)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_mod_sub_as_sub_err.out b/v_windows/v/old/vlib/v/checker/tests/import_mod_sub_as_sub_err.out
new file mode 100644
index 0000000..4caef12
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_mod_sub_as_sub_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/import_mod_sub_as_sub_err.vv:1:25: error: import alias `encoding.utf8 as utf8` is redundant
+    1 | import encoding.utf8 as utf8
+      |                         ~~~~
+    2 |
+    3 | fn main() {
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_mod_sub_as_sub_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_mod_sub_as_sub_err.vv
new file mode 100644
index 0000000..81846bf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_mod_sub_as_sub_err.vv
@@ -0,0 +1,5 @@
+import encoding.utf8 as utf8
+
+fn main() {
+    println(utf8.validate_str('añçá'))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_multiple_modules_err.out b/v_windows/v/old/vlib/v/checker/tests/import_multiple_modules_err.out
new file mode 100644
index 0000000..7688794
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_multiple_modules_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/import_multiple_modules_err.vv:1:13: error: cannot import multiple modules at a time
+    1 | import time math
+      |             ~~~~
+    2 | fn main() {
+    3 |     println(time.now().unix_time())
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_multiple_modules_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_multiple_modules_err.vv
new file mode 100644
index 0000000..d5d8033
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_multiple_modules_err.vv
@@ -0,0 +1,4 @@
+import time math
+fn main() {
+	println(time.now().unix_time())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_not_found_err.out b/v_windows/v/old/vlib/v/checker/tests/import_not_found_err.out
new file mode 100644
index 0000000..a41edfc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_not_found_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/import_not_found_err.vv:1:1: builder error: cannot import module "notexist" (not found)
+    1 | import notexist
+      | ~~~~~~~~~~~~~~~
+    2 | fn main() {
+    3 |     println(notexist.name)
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_not_found_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_not_found_err.vv
new file mode 100644
index 0000000..5e89bde
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_not_found_err.vv
@@ -0,0 +1,4 @@
+import notexist
+fn main() {
+	println(notexist.name)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_not_same_line_err.out b/v_windows/v/old/vlib/v/checker/tests/import_not_same_line_err.out
new file mode 100644
index 0000000..14a935e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_not_same_line_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/import_not_same_line_err.vv:2:2: error: `import` statements must be a single line
+    1 | import
+    2 |  time
+      |  ~~~~
+    3 | fn main() {
+    4 |     println(time.now())
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_not_same_line_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_not_same_line_err.vv
new file mode 100644
index 0000000..ad6401e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_not_same_line_err.vv
@@ -0,0 +1,5 @@
+import
+ time
+fn main() {
+	println(time.now())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_empty.out b/v_windows/v/old/vlib/v/checker/tests/import_symbol_empty.out
new file mode 100644
index 0000000..0592fed
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_empty.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/import_symbol_empty.vv:1:12: error: empty `os` import set, remove `{}`
+    1 | import os {}
+      |            ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_empty.vv b/v_windows/v/old/vlib/v/checker/tests/import_symbol_empty.vv
new file mode 100644
index 0000000..252aceb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_empty.vv
@@ -0,0 +1 @@
+import os {}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_fn_err.out b/v_windows/v/old/vlib/v/checker/tests/import_symbol_fn_err.out
new file mode 100644
index 0000000..5d74a05
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_fn_err.out
@@ -0,0 +1,11 @@
+vlib/v/checker/tests/import_symbol_fn_err.vv:1:17: error: module `crypto` has no constant or function `userper`
+    1 | import crypto { userper }
+      |                 ~~~~~~~
+    2 | fn main() {
+    3 |   usurper()
+vlib/v/checker/tests/import_symbol_fn_err.vv:3:3: error: unknown function: usurper
+    1 | import crypto { userper }
+    2 | fn main() {
+    3 |   usurper()
+      |   ~~~~~~~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_fn_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_symbol_fn_err.vv
new file mode 100644
index 0000000..04ba99b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_fn_err.vv
@@ -0,0 +1,4 @@
+import crypto { userper }
+fn main() {
+  usurper()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_invalid.out b/v_windows/v/old/vlib/v/checker/tests/import_symbol_invalid.out
new file mode 100644
index 0000000..2193b15
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_invalid.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/import_symbol_invalid.vv:1:17: error: import syntax error, please specify a valid fn or type name
+    1 | import crypto { *_v }
+      |                 ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_invalid.vv b/v_windows/v/old/vlib/v/checker/tests/import_symbol_invalid.vv
new file mode 100644
index 0000000..485c151
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_invalid.vv
@@ -0,0 +1 @@
+import crypto { *_v }
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_private_err.out b/v_windows/v/old/vlib/v/checker/tests/import_symbol_private_err.out
new file mode 100644
index 0000000..2d3d1e2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_private_err.out
@@ -0,0 +1,48 @@
+vlib/v/checker/tests/import_symbol_private_err.vv:3:20: error: module `time` function `since()` is private
+    1 | import v.scanner
+    2 | import v.parser
+    3 | import time { now, since }
+      |                    ~~~~~
+    4 | import io { ReaderWriterImpl }
+    5 |
+vlib/v/checker/tests/import_symbol_private_err.vv:4:13: error: module `io` type `ReaderWriterImpl` is private
+    2 | import v.parser
+    3 | import time { now, since }
+    4 | import io { ReaderWriterImpl }
+      |             ~~~~~~~~~~~~~~~~
+    5 | 
+    6 | fn main() {
+vlib/v/checker/tests/import_symbol_private_err.vv:7:18: error: constant `v.scanner.single_quote` is private
+    5 | 
+    6 | fn main() {
+    7 |     println(scanner.single_quote)
+      |                     ~~~~~~~~~~~~
+    8 |     println(parser.State.html)
+    9 |     since(now())
+vlib/v/checker/tests/import_symbol_private_err.vv:8:17: error: enum `v.parser.State` is private
+    6 | fn main() {
+    7 |     println(scanner.single_quote)
+    8 |     println(parser.State.html)
+      |                    ~~~~~~~~~~
+    9 |     since(now())
+   10 |     _ = map{'h': 2}.exists('h')
+vlib/v/checker/tests/import_symbol_private_err.vv:9:2: error: function `time.since` is private
+    7 |     println(scanner.single_quote)
+    8 |     println(parser.State.html)
+    9 |     since(now())
+      |     ~~~~~~~~~~~~
+   10 |     _ = map{'h': 2}.exists('h')
+   11 |     _ = ReaderWriterImpl{}
+vlib/v/checker/tests/import_symbol_private_err.vv:10:18: error: method `map[string]int.exists` is private
+    8 |     println(parser.State.html)
+    9 |     since(now())
+   10 |     _ = map{'h': 2}.exists('h')
+      |                     ~~~~~~~~~~~
+   11 |     _ = ReaderWriterImpl{}
+   12 | }
+vlib/v/checker/tests/import_symbol_private_err.vv:11:6: error: type `io.ReaderWriterImpl` is private
+    9 |     since(now())
+   10 |     _ = map{'h': 2}.exists('h')
+   11 |     _ = ReaderWriterImpl{}
+      |         ~~~~~~~~~~~~~~~~~~
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_private_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_symbol_private_err.vv
new file mode 100644
index 0000000..0957e86
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_private_err.vv
@@ -0,0 +1,12 @@
+import v.scanner
+import v.parser
+import time { now, since }
+import io { ReaderWriterImpl }
+
+fn main() {
+	println(scanner.single_quote)
+	println(parser.State.html)
+	since(now())
+	_ = map{'h': 2}.exists('h')
+	_ = ReaderWriterImpl{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_type_err.out b/v_windows/v/old/vlib/v/checker/tests/import_symbol_type_err.out
new file mode 100644
index 0000000..2c1cd9b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_type_err.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/import_symbol_type_err.vv:1:17: error: module `crypto` has no type `Coin`
+    1 | import crypto { Coin }
+      |                 ~~~~
+    2 | fn main() {
+    3 |   println(Coin{})
+vlib/v/checker/tests/import_symbol_type_err.vv:3:11: error: unknown type `crypto.Coin`.
+Did you mean `crypto.Hash`?
+    1 | import crypto { Coin }
+    2 | fn main() {
+    3 |   println(Coin{})
+      |           ~~~~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_symbol_type_err.vv
new file mode 100644
index 0000000..7eccd97
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_type_err.vv
@@ -0,0 +1,4 @@
+import crypto { Coin }
+fn main() {
+  println(Coin{})
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_unclosed.out b/v_windows/v/old/vlib/v/checker/tests/import_symbol_unclosed.out
new file mode 100644
index 0000000..2ab6a66
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_unclosed.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/import_symbol_unclosed.vv:1:28: error: import syntax error, no closing `}`
+    1 | import crypto.sha256 { sum ]
+      |                            ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_symbol_unclosed.vv b/v_windows/v/old/vlib/v/checker/tests/import_symbol_unclosed.vv
new file mode 100644
index 0000000..799a636
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_symbol_unclosed.vv
@@ -0,0 +1 @@
+import crypto.sha256 { sum ]
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_syntax_err.out b/v_windows/v/old/vlib/v/checker/tests/import_syntax_err.out
new file mode 100644
index 0000000..06b3499
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_syntax_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/import_syntax_err.vv:1:12: error: cannot import multiple modules at a time
+    1 | import time, os
+      |            ^
+    2 | fn main() {
+    3 |     println(time.now())
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_syntax_err.vv b/v_windows/v/old/vlib/v/checker/tests/import_syntax_err.vv
new file mode 100644
index 0000000..2649ca6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_syntax_err.vv
@@ -0,0 +1,4 @@
+import time, os
+fn main() {
+	println(time.now())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_unused_warning.out b/v_windows/v/old/vlib/v/checker/tests/import_unused_warning.out
new file mode 100644
index 0000000..38df8cd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_unused_warning.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/import_unused_warning.vv:1:8: warning: module 'time' is imported but never used 
+    1 | import time
+      |        ~~~~
+    2 | fn main() {
+    3 |     println('hello, world')
diff --git a/v_windows/v/old/vlib/v/checker/tests/import_unused_warning.vv b/v_windows/v/old/vlib/v/checker/tests/import_unused_warning.vv
new file mode 100644
index 0000000..1fb573f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/import_unused_warning.vv
@@ -0,0 +1,4 @@
+import time
+fn main() {
+	println('hello, world')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/in_mismatch_type.out b/v_windows/v/old/vlib/v/checker/tests/in_mismatch_type.out
new file mode 100644
index 0000000..d6e9e12
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/in_mismatch_type.out
@@ -0,0 +1,77 @@
+vlib/v/checker/tests/in_mismatch_type.vv:10:5: error: left operand to `in` does not match the array element type: expected `string`, not `int literal`
+    8 |     }
+    9 |     s := 'abcd'
+   10 |     if 1 in a_s {
+      |        ~~~~~~~~
+   11 |         println('ok')
+   12 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:13:5: error: left operand to `in` does not match the map key type: expected `string`, not `int literal`
+   11 |         println('ok')
+   12 |     }
+   13 |     if 2 in m {
+      |        ~~~~~~
+   14 |         println('yeah')
+   15 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:16:5: error: use `str.contains(substr)` instead of `substr in str`
+   14 |         println('yeah')
+   15 |     }
+   16 |     if 3 in s {
+      |        ~~~~~~
+   17 |         println('dope')
+   18 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:19:5: error: use `str.contains(substr)` instead of `substr in str`
+   17 |         println('dope')
+   18 |     }
+   19 |     if `a` in s {
+      |        ~~~~~~~~
+   20 |         println("oh no :'(")
+   21 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:22:7: error: `in` can only be used with an array/map/string
+   20 |         println("oh no :'(")
+   21 |     }
+   22 |     if 1 in 12 {
+      |          ~~
+   23 |         println('right')
+   24 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:25:5: error: left operand to `in` does not match the map key type: expected `string`, not `Int`
+   23 |         println('right')
+   24 |     }
+   25 |     if Int(2) in m {
+      |        ~~~~~~~~~~~
+   26 |         println('yeah')
+   27 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:28:5: error: left operand to `in` does not match the array element type: expected `int`, not `string`
+   26 |         println('yeah')
+   27 |     }
+   28 |     if '3' in a_i {
+      |        ~~~~~~~~~~
+   29 |         println('sure')
+   30 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:31:5: error: left operand to `in` does not match the array element type: expected `int`, not `string`
+   29 |         println('sure')
+   30 |     }
+   31 |     if '2' in a_i {
+      |        ~~~~~~~~~~
+   32 |         println('all right')
+   33 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:34:5: error: left operand to `!in` does not match the array element type: expected `string`, not `int literal`
+   32 |         println('all right')
+   33 |     }
+   34 |     if 1 !in a_s {
+      |        ~~~~~~~~~
+   35 |         println('ok')
+   36 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:37:5: error: left operand to `!in` does not match the array element type: expected `int`, not `string`
+   35 |         println('ok')
+   36 |     }
+   37 |     if '1' !in a_i {
+      |        ~~~~~~~~~~~
+   38 |         println('good')
+   39 |     }
+vlib/v/checker/tests/in_mismatch_type.vv:41:5: error: left operand to `!in` does not match the map key type: expected `string`, not `int literal`
+   39 |     }
+   40 |
+   41 |     if 5 !in m {
+      |        ~~~~~~~
+   42 |         println('yay')
+   43 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/in_mismatch_type.vv b/v_windows/v/old/vlib/v/checker/tests/in_mismatch_type.vv
new file mode 100644
index 0000000..4a5dc69
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/in_mismatch_type.vv
@@ -0,0 +1,44 @@
+type Int = int
+
+fn main() {
+	a_i := [1, 2, 3]
+	a_s := ['1', '2', '3']
+	m := map{
+		'test': 1
+	}
+	s := 'abcd'
+	if 1 in a_s {
+		println('ok')
+	}
+	if 2 in m {
+		println('yeah')
+	}
+	if 3 in s {
+		println('dope')
+	}
+	if `a` in s {
+		println("oh no :'(")
+	}
+	if 1 in 12 {
+		println('right')
+	}
+	if Int(2) in m {
+		println('yeah')
+	}
+	if '3' in a_i {
+		println('sure')
+	}
+	if '2' in a_i {
+		println('all right')
+	}
+	if 1 !in a_s {
+		println('ok')
+	}
+	if '1' !in a_i {
+		println('good')
+	}
+
+	if 5 !in m {
+		println('yay')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_for_in_name_variable.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_for_in_name_variable.out
new file mode 100644
index 0000000..610ef46
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_for_in_name_variable.out
@@ -0,0 +1,8 @@
+vlib/v/checker/tests/incorrect_for_in_name_variable.vv:3:6: error: variable name `_aa` cannot start with `_`
+    1 | fn main() {
+    2 |     a := [1,2,3]
+    3 |     for _aa in a {
+      |         ~~~
+    4 |         println(_aa)
+    5 |     }
+	
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_for_in_name_variable.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_for_in_name_variable.vv
new file mode 100644
index 0000000..888fd60
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_for_in_name_variable.vv
@@ -0,0 +1,6 @@
+fn main() {
+	a := [1,2,3]
+	for _aa in a {
+		println(_aa)
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_alias_type.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_alias_type.out
new file mode 100644
index 0000000..820e8d5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_alias_type.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/incorrect_name_alias_type.vv:1:1: error: type alias `integer` must begin with capital letter
+    1 | type integer = int
+      | ~~~~~~~~~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_alias_type.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_alias_type.vv
new file mode 100644
index 0000000..7e2d363
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_alias_type.vv
@@ -0,0 +1 @@
+type integer = int
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_const.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_const.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_const.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_const.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_const.vv
new file mode 100644
index 0000000..50f553f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_const.vv
@@ -0,0 +1,3 @@
+const (
+	_my_const = 0
+)
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum.out
new file mode 100644
index 0000000..27a4392
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/incorrect_name_enum.vv:1:1: error: enum name `color` must begin with capital letter
+    1 | enum color {
+      | ~~~~~~~~~~
+    2 |     green
+    3 |     yellow
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum.vv
new file mode 100644
index 0000000..90c4d4d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum.vv
@@ -0,0 +1,4 @@
+enum color {
+    green
+    yellow
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum_field.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum_field.out
new file mode 100644
index 0000000..04f2748
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum_field.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/incorrect_name_enum_field.vv:2:5: error: field name `Green` cannot contain uppercase letters, use snake_case instead
+    1 | enum Color {
+    2 |     Green
+      |     ~~~~~
+    3 |     red
+    4 |     blue
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum_field.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum_field.vv
new file mode 100644
index 0000000..8cb0031
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_enum_field.vv
@@ -0,0 +1,5 @@
+enum Color {
+    Green
+    red
+    blue
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_fn_type.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_fn_type.out
new file mode 100644
index 0000000..4ded743
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_fn_type.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/incorrect_name_fn_type.vv:1:1: error: fn type `callback` must begin with capital letter
+    1 | type callback = fn ()
+      | ~~~~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_fn_type.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_fn_type.vv
new file mode 100644
index 0000000..f565315
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_fn_type.vv
@@ -0,0 +1 @@
+type callback = fn ()
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_function.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_function.out
new file mode 100644
index 0000000..0826b36
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_function.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/incorrect_name_function.vv:1:1: error: function name `_my_fn` cannot start with `_`
+    1 | fn _my_fn() {}
+      | ~~~~~~~~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_function.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_function.vv
new file mode 100644
index 0000000..b75a1a2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_function.vv
@@ -0,0 +1 @@
+fn _my_fn() {}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface.out
new file mode 100644
index 0000000..95a49b9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/incorrect_name_interface.vv:1:1: error: interface name `_MyInterface` must begin with capital letter
+    1 | interface _MyInterface {}
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface.vv
new file mode 100644
index 0000000..abe6cb8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface.vv
@@ -0,0 +1 @@
+interface _MyInterface {}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface_method.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface_method.out
new file mode 100644
index 0000000..daeda3e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface_method.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/incorrect_name_interface_method.vv:2:5: error: method name `_speak` cannot start with `_`
+    1 | interface MyInterface {
+    2 |     _speak()
+      |     ~~~~~~~~
+    3 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface_method.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface_method.vv
new file mode 100644
index 0000000..2ab12be
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_interface_method.vv
@@ -0,0 +1,3 @@
+interface MyInterface {
+    _speak()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_module.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_module.out
new file mode 100644
index 0000000..4edc08e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_module.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/incorrect_name_module.vv:1:1: error: module name `_A` cannot start with `_`
+    1 | module _A
+      | ~~~~~~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_module.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_module.vv
new file mode 100644
index 0000000..50526ca
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_module.vv
@@ -0,0 +1 @@
+module _A
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct.out
new file mode 100644
index 0000000..03f1a93
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/incorrect_name_struct.vv:1:8: error: struct name `abc` must begin with capital letter
+    1 | struct abc {}
+      |        ~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct.vv
new file mode 100644
index 0000000..0c77ebc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct.vv
@@ -0,0 +1 @@
+struct abc {}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct_field.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct_field.out
new file mode 100644
index 0000000..22fddfc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct_field.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/incorrect_name_struct_field.vv:2:5: error: field name `_a` cannot start with `_`
+    1 | struct Abc {
+    2 |     _a int
+      |     ~~~~~~
+    3 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct_field.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct_field.vv
new file mode 100644
index 0000000..b1b2205
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_struct_field.vv
@@ -0,0 +1,3 @@
+struct Abc {
+    _a int
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_sum_type.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_sum_type.out
new file mode 100644
index 0000000..91a0412
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_sum_type.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/incorrect_name_sum_type.vv:1:1: error: sum type `integer` must begin with capital letter
+    1 | type integer = i8 | i16 | int | i64
+      | ~~~~~~~~~~~~
+    2 | type Integer = i8 | i16 | int | i64
+    3 |
+vlib/v/checker/tests/incorrect_name_sum_type.vv:4:1: error: method overrides built-in sum type method
+    2 | type Integer = i8 | i16 | int | i64
+    3 | 
+    4 | fn (i Integer) type_name() {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~
+    5 | }
+    6 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_sum_type.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_sum_type.vv
new file mode 100644
index 0000000..e73300d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_sum_type.vv
@@ -0,0 +1,6 @@
+type integer = i8 | i16 | int | i64
+type Integer = i8 | i16 | int | i64
+
+fn (i Integer) type_name() {
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_variable.out b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_variable.out
new file mode 100644
index 0000000..7a3de82
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_variable.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/incorrect_name_variable.vv:2:2: error: variable name `_abc` cannot start with `_`
+    1 | fn main() {
+    2 |     _abc := 1
+      |     ~~~~
+    3 |     _ = _abc
+    4 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/incorrect_name_variable.vv b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_variable.vv
new file mode 100644
index 0000000..d4d4295
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/incorrect_name_variable.vv
@@ -0,0 +1,4 @@
+fn main() {
+	_abc := 1
+	_ = _abc
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/index_expr.out b/v_windows/v/old/vlib/v/checker/tests/index_expr.out
new file mode 100644
index 0000000..90aa0a2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/index_expr.out
@@ -0,0 +1,69 @@
+vlib/v/checker/tests/index_expr.vv:3:7: error: type `int` does not support indexing
+    1 | fn test_invalid_index() {
+    2 |     v := 4
+    3 |     _ = v[0]
+      |          ~~~
+    4 | 
+    5 |     a := [2]
+vlib/v/checker/tests/index_expr.vv:6:7: error: non-integer index `[]int` (array type `[]int`)
+    4 | 
+    5 |     a := [2]
+    6 |     _ = a[a]
+      |          ~~~
+    7 |     _ = a[-1]
+    8 | }
+vlib/v/checker/tests/index_expr.vv:7:8: error: negative index `-1`
+    5 |     a := [2]
+    6 |     _ = a[a]
+    7 |     _ = a[-1]
+      |           ~~
+    8 | }
+    9 |
+vlib/v/checker/tests/index_expr.vv:12:7: error: type `int` does not support indexing
+   10 | fn test_invalid_slice() {
+   11 |     v := 4
+   12 |     _ = v[1..]
+      |          ~~~~~
+   13 |     _ = v[..1]
+   14 |
+vlib/v/checker/tests/index_expr.vv:13:7: error: type `int` does not support indexing
+   11 |     v := 4
+   12 |     _ = v[1..]
+   13 |     _ = v[..1]
+      |          ~~~~~
+   14 | 
+   15 |     a := [2]
+vlib/v/checker/tests/index_expr.vv:16:7: error: non-integer index `[]int` (array type `[]int`)
+   14 | 
+   15 |     a := [2]
+   16 |     _ = a[a..]
+      |          ~~~~~
+   17 |     _ = a[..a]
+   18 |     _ = a[-1..]
+vlib/v/checker/tests/index_expr.vv:17:7: error: non-integer index `[]int` (array type `[]int`)
+   15 |     a := [2]
+   16 |     _ = a[a..]
+   17 |     _ = a[..a]
+      |          ~~~~~
+   18 |     _ = a[-1..]
+   19 |     _ = a[..-1]
+vlib/v/checker/tests/index_expr.vv:18:8: error: negative index `-1`
+   16 |     _ = a[a..]
+   17 |     _ = a[..a]
+   18 |     _ = a[-1..]
+      |           ~~
+   19 |     _ = a[..-1]
+   20 |     _ = a[-1..-2]
+vlib/v/checker/tests/index_expr.vv:19:10: error: negative index `-1`
+   17 |     _ = a[..a]
+   18 |     _ = a[-1..]
+   19 |     _ = a[..-1]
+      |             ~~
+   20 |     _ = a[-1..-2]
+   21 | }
+vlib/v/checker/tests/index_expr.vv:20:8: error: negative index `-1`
+   18 |     _ = a[-1..]
+   19 |     _ = a[..-1]
+   20 |     _ = a[-1..-2]
+      |           ~~
+   21 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/index_expr.vv b/v_windows/v/old/vlib/v/checker/tests/index_expr.vv
new file mode 100644
index 0000000..072661d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/index_expr.vv
@@ -0,0 +1,21 @@
+fn test_invalid_index() {
+	v := 4
+	_ = v[0]
+
+	a := [2]
+	_ = a[a]
+	_ = a[-1]
+}
+
+fn test_invalid_slice() {
+	v := 4
+	_ = v[1..]
+	_ = v[..1]
+
+	a := [2]
+	_ = a[a..]
+	_ = a[..a]
+	_ = a[-1..]
+	_ = a[..-1]
+	_ = a[-1..-2]
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/infix_err.out b/v_windows/v/old/vlib/v/checker/tests/infix_err.out
new file mode 100644
index 0000000..3637169
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/infix_err.out
@@ -0,0 +1,81 @@
+vlib/v/checker/tests/infix_err.vv:7:5: error: mismatched types `string` and `?string`
+    5 |     return none
+    6 | }
+    7 | _ = '' + f()
+      |     ~~~~~~~~
+    8 | _ = f() + ''
+    9 | _ = f() + f()
+vlib/v/checker/tests/infix_err.vv:8:5: error: mismatched types `?string` and `string`
+    6 | }
+    7 | _ = '' + f()
+    8 | _ = f() + ''
+      |     ~~~~~~~~
+    9 | _ = f() + f()
+   10 |
+vlib/v/checker/tests/infix_err.vv:9:9: error: `+` cannot be used with `?string`
+    7 | _ = '' + f()
+    8 | _ = f() + ''
+    9 | _ = f() + f()
+      |         ^
+   10 | 
+   11 | _ = 4 + g()
+vlib/v/checker/tests/infix_err.vv:11:7: error: `+` cannot be used with `?int`
+    9 | _ = f() + f()
+   10 | 
+   11 | _ = 4 + g()
+      |       ^
+   12 | _ = int(0) + g() // FIXME not detected
+   13 | _ = g() + int(3)
+vlib/v/checker/tests/infix_err.vv:12:5: error: unwrapped optional cannot be used in an infix expression
+   10 | 
+   11 | _ = 4 + g()
+   12 | _ = int(0) + g() // FIXME not detected
+      |     ~~~~~~~~~~~~
+   13 | _ = g() + int(3)
+   14 | _ = g() + 3
+vlib/v/checker/tests/infix_err.vv:13:9: error: `+` cannot be used with `?int`
+   11 | _ = 4 + g()
+   12 | _ = int(0) + g() // FIXME not detected
+   13 | _ = g() + int(3)
+      |         ^
+   14 | _ = g() + 3
+   15 |
+vlib/v/checker/tests/infix_err.vv:14:9: error: `+` cannot be used with `?int`
+   12 | _ = int(0) + g() // FIXME not detected
+   13 | _ = g() + int(3)
+   14 | _ = g() + 3
+      |         ^
+   15 | 
+   16 | // binary operands
+vlib/v/checker/tests/infix_err.vv:17:5: error: left operand for `&&` is not a boolean
+   15 | 
+   16 | // binary operands
+   17 | _ = 1 && 2
+      |     ^
+   18 | _ = true || 2
+   19 |
+vlib/v/checker/tests/infix_err.vv:18:13: error: right operand for `||` is not a boolean
+   16 | // binary operands
+   17 | _ = 1 && 2
+   18 | _ = true || 2
+      |             ^
+   19 | 
+   20 | // boolean expressions
+vlib/v/checker/tests/infix_err.vv:21:22: error: ambiguous boolean expression. use `()` to ensure correct order of operations
+   19 | 
+   20 | // boolean expressions
+   21 | _ = 1 == 1 && 2 == 2 || 3 == 3
+      |                      ~~
+   22 | _ = 1 == 1
+   23 |     && 2 == 2 || 3 == 3
+vlib/v/checker/tests/infix_err.vv:23:12: error: ambiguous boolean expression. use `()` to ensure correct order of operations
+   21 | _ = 1 == 1 && 2 == 2 || 3 == 3
+   22 | _ = 1 == 1
+   23 |     && 2 == 2 || 3 == 3
+      |               ~~
+   24 |     && 4 == 4
+vlib/v/checker/tests/infix_err.vv:24:2: error: ambiguous boolean expression. use `()` to ensure correct order of operations
+   22 | _ = 1 == 1
+   23 |     && 2 == 2 || 3 == 3
+   24 |     && 4 == 4
+      |     ~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/infix_err.vv b/v_windows/v/old/vlib/v/checker/tests/infix_err.vv
new file mode 100644
index 0000000..13381b4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/infix_err.vv
@@ -0,0 +1,24 @@
+fn f() ?string {
+	return none
+}
+fn g() ?int {
+	return none
+}
+_ = '' + f()
+_ = f() + ''
+_ = f() + f()
+
+_ = 4 + g()
+_ = int(0) + g() // FIXME not detected
+_ = g() + int(3)
+_ = g() + 3
+
+// binary operands
+_ = 1 && 2
+_ = true || 2
+
+// boolean expressions
+_ = 1 == 1 && 2 == 2 || 3 == 3
+_ = 1 == 1
+	&& 2 == 2 || 3 == 3
+	&& 4 == 4
diff --git a/v_windows/v/old/vlib/v/checker/tests/int_modulo_by_zero_err.out b/v_windows/v/old/vlib/v/checker/tests/int_modulo_by_zero_err.out
new file mode 100644
index 0000000..c9d0e2d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/int_modulo_by_zero_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/int_modulo_by_zero_err.vv:2:17: error: modulo by zero 
+    1 | fn main() {
+    2 |     println(3 % 0)
+      |                 ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/int_modulo_by_zero_err.vv b/v_windows/v/old/vlib/v/checker/tests/int_modulo_by_zero_err.vv
new file mode 100644
index 0000000..8945861
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/int_modulo_by_zero_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(3 % 0)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_implementing_interface.out b/v_windows/v/old/vlib/v/checker/tests/interface_implementing_interface.out
new file mode 100644
index 0000000..b2476ce
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_implementing_interface.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/interface_implementing_interface.vv:15:10: error: cannot implement interface `Thing` with a different interface `Animal`
+   13 | dog := Dog{}
+   14 | animal := Animal(dog)
+   15 | thing := Thing(animal)
+      |          ~~~~~~~~~~~~~
+   16 | println(thing)
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_implementing_interface.vv b/v_windows/v/old/vlib/v/checker/tests/interface_implementing_interface.vv
new file mode 100644
index 0000000..a71e9ea
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_implementing_interface.vv
@@ -0,0 +1,16 @@
+interface Thing {
+    kind string
+}
+
+interface Animal {
+    kind string
+}
+
+struct Dog {
+    kind string = 'labrador'
+}
+
+dog := Dog{}
+animal := Animal(dog)
+thing := Thing(animal)
+println(thing)
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_implementing_own_interface_method.out b/v_windows/v/old/vlib/v/checker/tests/interface_implementing_own_interface_method.out
new file mode 100644
index 0000000..afa4876
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_implementing_own_interface_method.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/interface_implementing_own_interface_method.vv:5:1: error: interface `Animal` cannot implement its own interface method `speak`
+    3 | }
+    4 | 
+    5 | fn (a Animal) speak() {
+      | ~~~~~~~~~~~~~~~~~~~~~
+    6 |     println('speaking')
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_implementing_own_interface_method.vv b/v_windows/v/old/vlib/v/checker/tests/interface_implementing_own_interface_method.vv
new file mode 100644
index 0000000..9881bd7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_implementing_own_interface_method.vv
@@ -0,0 +1,7 @@
+interface Animal {
+    speak()
+}
+
+fn (a Animal) speak() {
+    println('speaking')
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_init_err.out b/v_windows/v/old/vlib/v/checker/tests/interface_init_err.out
new file mode 100644
index 0000000..238395c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_init_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/interface_init_err.vv:15:7: error: interface field `Server.handler` must be initialized
+   13 | 
+   14 | fn main() {
+   15 |     _ := Server{}
+      |          ~~~~~~~~
+   16 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_init_err.vv b/v_windows/v/old/vlib/v/checker/tests/interface_init_err.vv
new file mode 100644
index 0000000..e2def73
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_init_err.vv
@@ -0,0 +1,16 @@
+interface Handler {
+	foo string
+	handle(int) int
+}
+
+struct Server {
+	handler Handler
+}
+
+fn (s Server) handle(x int) int {
+	return x
+}
+
+fn main() {
+	_ := Server{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_return_parameter_err.out b/v_windows/v/old/vlib/v/checker/tests/interface_return_parameter_err.out
new file mode 100644
index 0000000..ac3f23d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_return_parameter_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/interface_return_parameter_err.vv:2:17: error: unknown type `Baz`.
+Did you mean `Foo`?
+    1 | interface Foo {
+    2 |     bar(string) []Baz
+      |                 ~~~~~
+    3 |     bar2(Bax) string
+    4 | }
+vlib/v/checker/tests/interface_return_parameter_err.vv:3:10: error: unknown type `Bax`.
+Did you mean `Foo`?
+    1 | interface Foo {
+    2 |     bar(string) []Baz
+    3 |     bar2(Bax) string
+      |          ~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_return_parameter_err.vv b/v_windows/v/old/vlib/v/checker/tests/interface_return_parameter_err.vv
new file mode 100644
index 0000000..e6168cf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_return_parameter_err.vv
@@ -0,0 +1,4 @@
+interface Foo {
+    bar(string) []Baz
+    bar2(Bax) string
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_too_many_embedding_levels.out b/v_windows/v/old/vlib/v/checker/tests/interface_too_many_embedding_levels.out
new file mode 100644
index 0000000..669fb01
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_too_many_embedding_levels.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/interface_too_many_embedding_levels.vv:9:1: error: too many interface embedding levels: 101, for interface `I103`
+    7 | }
+    8 | 
+    9 | interface I103 {
+      | ~~~~~~~~~~~~~~~~
+   10 |     I102
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/interface_too_many_embedding_levels.vv b/v_windows/v/old/vlib/v/checker/tests/interface_too_many_embedding_levels.vv
new file mode 100644
index 0000000..6975ef0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interface_too_many_embedding_levels.vv
@@ -0,0 +1,431 @@
+interface I1 {
+	I0
+}
+
+interface I2 {
+	I1
+}
+
+interface I103 {
+	I102
+}
+
+interface I102 {
+	I101
+}
+
+interface I101 {
+	I100
+}
+
+interface I3 {
+	I2
+}
+
+interface I4 {
+	I3
+}
+
+interface I5 {
+	I4
+}
+
+interface I6 {
+	I5
+}
+
+interface I7 {
+	I6
+}
+
+interface I8 {
+	I7
+}
+
+interface I9 {
+	I8
+}
+
+interface I10 {
+	I9
+}
+
+interface I11 {
+	I10
+}
+
+interface I12 {
+	I11
+}
+
+interface I13 {
+	I12
+}
+
+interface I14 {
+	I13
+}
+
+interface I15 {
+	I14
+}
+
+interface I16 {
+	I15
+}
+
+interface I17 {
+	I16
+}
+
+interface I18 {
+	I17
+}
+
+interface I19 {
+	I18
+}
+
+interface I20 {
+	I19
+}
+
+interface I21 {
+	I20
+}
+
+interface I22 {
+	I21
+}
+
+interface I23 {
+	I22
+}
+
+interface I24 {
+	I23
+}
+
+interface I25 {
+	I24
+}
+
+interface I26 {
+	I25
+}
+
+interface I27 {
+	I26
+}
+
+interface I28 {
+	I27
+}
+
+interface I29 {
+	I28
+}
+
+interface I30 {
+	I29
+}
+
+interface I31 {
+	I30
+}
+
+interface I32 {
+	I31
+}
+
+interface I33 {
+	I32
+}
+
+interface I34 {
+	I33
+}
+
+interface I35 {
+	I34
+}
+
+interface I36 {
+	I35
+}
+
+interface I37 {
+	I36
+}
+
+interface I38 {
+	I37
+}
+
+interface I39 {
+	I38
+}
+
+interface I40 {
+	I39
+}
+
+interface I41 {
+	I40
+}
+
+interface I42 {
+	I41
+}
+
+interface I43 {
+	I42
+}
+
+interface I44 {
+	I43
+}
+
+interface I45 {
+	I44
+}
+
+interface I46 {
+	I45
+}
+
+interface I47 {
+	I46
+}
+
+interface I48 {
+	I47
+}
+
+interface I49 {
+	I48
+}
+
+interface I50 {
+	I49
+}
+
+interface I51 {
+	I50
+}
+
+interface I52 {
+	I51
+}
+
+interface I53 {
+	I52
+}
+
+interface I54 {
+	I53
+}
+
+interface I55 {
+	I54
+}
+
+interface I56 {
+	I55
+}
+
+interface I57 {
+	I56
+}
+
+interface I58 {
+	I57
+}
+
+interface I59 {
+	I58
+}
+
+interface I60 {
+	I59
+}
+
+interface I61 {
+	I60
+}
+
+interface I62 {
+	I61
+}
+
+interface I63 {
+	I62
+}
+
+interface I64 {
+	I63
+}
+
+interface I65 {
+	I64
+}
+
+interface I66 {
+	I65
+}
+
+interface I67 {
+	I66
+}
+
+interface I68 {
+	I67
+}
+
+interface I69 {
+	I68
+}
+
+interface I70 {
+	I69
+}
+
+interface I71 {
+	I70
+}
+
+interface I72 {
+	I71
+}
+
+interface I73 {
+	I72
+}
+
+interface I74 {
+	I73
+}
+
+interface I75 {
+	I74
+}
+
+interface I76 {
+	I75
+}
+
+interface I77 {
+	I76
+}
+
+interface I78 {
+	I77
+}
+
+interface I79 {
+	I78
+}
+
+interface I80 {
+	I79
+}
+
+interface I81 {
+	I80
+}
+
+interface I82 {
+	I81
+}
+
+interface I83 {
+	I82
+}
+
+interface I84 {
+	I83
+}
+
+interface I85 {
+	I84
+}
+
+interface I86 {
+	I85
+}
+
+interface I87 {
+	I86
+}
+
+interface I88 {
+	I87
+}
+
+interface I89 {
+	I88
+}
+
+interface I90 {
+	I89
+}
+
+interface I91 {
+	I90
+}
+
+interface I92 {
+	I91
+}
+
+interface I93 {
+	I92
+}
+
+interface I94 {
+	I93
+}
+
+interface I95 {
+	I94
+}
+
+interface I96 {
+	I95
+}
+
+interface I97 {
+	I96
+}
+
+interface I98 {
+	I97
+}
+
+interface I99 {
+	I98
+}
+
+interface I100 {
+	I99
+}
+
+interface I0 {
+	m999() int
+}
+
+struct Abc {
+	x int = 123
+}
+
+fn (s Abc) m999() int {
+	return 999
+}
+
+fn main() {
+	a := Abc{}
+	dump(a)
+	i := I103(a)
+	dump(i)
+	assert i.m999() == 999
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/interpolation_recursive_str_err.out b/v_windows/v/old/vlib/v/checker/tests/interpolation_recursive_str_err.out
new file mode 100644
index 0000000..c47f72f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interpolation_recursive_str_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/interpolation_recursive_str_err.vv:8:8: error: cannot call `str()` method recursively
+    6 |
+    7 | fn (t Test) str() string {
+    8 |     _ = '$t'
+      |           ^
+    9 |     return 'test'
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/interpolation_recursive_str_err.vv b/v_windows/v/old/vlib/v/checker/tests/interpolation_recursive_str_err.vv
new file mode 100644
index 0000000..4f3f3d8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/interpolation_recursive_str_err.vv
@@ -0,0 +1,15 @@
+module main
+
+struct Test {
+	a int
+}
+
+fn (t Test) str() string {
+	_ = '$t'
+	return 'test'
+}
+
+fn main() {
+	a := Test{}
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/invalid_char_err.out b/v_windows/v/old/vlib/v/checker/tests/invalid_char_err.out
new file mode 100644
index 0000000..e4a2b5c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/invalid_char_err.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/invalid_char_err.vv:1:1: error: invalid character `🐈`
+    1 | 🐈println('')
+      | ^
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/invalid_char_err.vv b/v_windows/v/old/vlib/v/checker/tests/invalid_char_err.vv
new file mode 100644
index 0000000..0a27589
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/invalid_char_err.vv
@@ -0,0 +1 @@
+🐈println('')
diff --git a/v_windows/v/old/vlib/v/checker/tests/invalid_property.out b/v_windows/v/old/vlib/v/checker/tests/invalid_property.out
new file mode 100644
index 0000000..e7839a4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/invalid_property.out
@@ -0,0 +1,18 @@
+vlib/v/checker/tests/invalid_property.vv:2:7: error: `string` has no property `length`
+    1 | s :=''
+    2 | _ = s.length
+      |       ~~~~~~
+    3 | _ = [1,2].foo
+    4 |
+vlib/v/checker/tests/invalid_property.vv:3:11: error: `[]int` has no property `foo`
+    1 | s :=''
+    2 | _ = s.length
+    3 | _ = [1,2].foo
+      |           ~~~
+    4 | 
+    5 | mut fa := [3,4]!
+vlib/v/checker/tests/invalid_property.vv:6:8: error: `[2]int` has no property `bar`
+    4 | 
+    5 | mut fa := [3,4]!
+    6 | _ = fa.bar
+      |        ~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/invalid_property.vv b/v_windows/v/old/vlib/v/checker/tests/invalid_property.vv
new file mode 100644
index 0000000..427c2e7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/invalid_property.vv
@@ -0,0 +1,6 @@
+s :=''
+_ = s.length
+_ = [1,2].foo
+
+mut fa := [3,4]!
+_ = fa.bar
diff --git a/v_windows/v/old/vlib/v/checker/tests/invalid_vweb_param_type.out b/v_windows/v/old/vlib/v/checker/tests/invalid_vweb_param_type.out
new file mode 100644
index 0000000..7333400
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/invalid_vweb_param_type.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/invalid_vweb_param_type.vv:8:24: error: invalid type `[]bool` for parameter `list` in vweb app method `index`
+    6 | 
+    7 | ['/:list'; get]
+    8 | fn (mut app App) index(list []bool) vweb.Result {
+      |                        ~~~~
+    9 |     return app.text('')
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/invalid_vweb_param_type.vv b/v_windows/v/old/vlib/v/checker/tests/invalid_vweb_param_type.vv
new file mode 100644
index 0000000..6274830
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/invalid_vweb_param_type.vv
@@ -0,0 +1,12 @@
+import vweb
+
+struct App {
+	vweb.Context
+}
+
+['/:list'; get]
+fn (mut app App) index(list []bool) vweb.Result {
+	return app.text('')
+}
+
+vweb.run(&App{}, 5000)
diff --git a/v_windows/v/old/vlib/v/checker/tests/invert_other_types_bits_error.out b/v_windows/v/old/vlib/v/checker/tests/invert_other_types_bits_error.out
new file mode 100644
index 0000000..ad8c86f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/invert_other_types_bits_error.out
@@ -0,0 +1,26 @@
+vlib/v/checker/tests/invert_other_types_bits_error.vv:2:13: error: operator ~ only defined on int types
+    1 | fn main() {
+    2 |     println(~3.0)
+      |             ^
+    3 |     println(~10.5)
+    4 |     println(~'2')
+vlib/v/checker/tests/invert_other_types_bits_error.vv:3:13: error: operator ~ only defined on int types
+    1 | fn main() {
+    2 |     println(~3.0)
+    3 |     println(~10.5)
+      |             ^
+    4 |     println(~'2')
+    5 |     println(~[2, 4, 6])
+vlib/v/checker/tests/invert_other_types_bits_error.vv:4:13: error: operator ~ only defined on int types
+    2 |     println(~3.0)
+    3 |     println(~10.5)
+    4 |     println(~'2')
+      |             ^
+    5 |     println(~[2, 4, 6])
+    6 | }
+vlib/v/checker/tests/invert_other_types_bits_error.vv:5:13: error: operator ~ only defined on int types
+    3 |     println(~10.5)
+    4 |     println(~'2')
+    5 |     println(~[2, 4, 6])
+      |             ^
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/invert_other_types_bits_error.vv b/v_windows/v/old/vlib/v/checker/tests/invert_other_types_bits_error.vv
new file mode 100644
index 0000000..ad74f64
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/invert_other_types_bits_error.vv
@@ -0,0 +1,6 @@
+fn main() {
+    println(~3.0)
+    println(~10.5)
+    println(~'2')
+    println(~[2, 4, 6])
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/is_type_invalid.out b/v_windows/v/old/vlib/v/checker/tests/is_type_invalid.out
new file mode 100644
index 0000000..0459e96
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/is_type_invalid.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/is_type_invalid.vv:14:12: error: `IoS` has no variant `byte`
+   12 |
+   13 | fn main() {
+   14 |     if IoS(1) is byte {
+      |               ~~
+   15 |         println('not cool')
+   16 |     }
+vlib/v/checker/tests/is_type_invalid.vv:18:7: error: `Cat` doesn't implement method `speak` of interface `Animal`
+   16 |     }
+   17 |     a := Animal(Dog{})
+   18 |     if a is Cat {
+      |          ~~
+   19 |         println('not cool either')
+   20 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/is_type_invalid.vv b/v_windows/v/old/vlib/v/checker/tests/is_type_invalid.vv
new file mode 100644
index 0000000..2e7f774
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/is_type_invalid.vv
@@ -0,0 +1,21 @@
+type IoS = int | string
+
+interface Animal {
+	speak()
+}
+
+struct Dog {}
+
+fn (d Dog) speak() {}
+
+struct Cat {}
+
+fn main() {
+	if IoS(1) is byte {
+		println('not cool')
+	}
+	a := Animal(Dog{})
+	if a is Cat {
+		println('not cool either')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/is_type_not_exist.out b/v_windows/v/old/vlib/v/checker/tests/is_type_not_exist.out
new file mode 100644
index 0000000..1c52d7a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/is_type_not_exist.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/is_type_not_exist.vv:8:10: error: is: type `SomethingThatDontExist` does not exist
+    6 | 
+    7 | fn fn_with_sum_type_param(i Integer) {
+    8 |     if i is SomethingThatDontExist {
+      |             ~~~~~~~~~~~~~~~~~~~~~~
+    9 |         println('It should fail !')
+   10 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/is_type_not_exist.vv b/v_windows/v/old/vlib/v/checker/tests/is_type_not_exist.vv
new file mode 100644
index 0000000..e50859b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/is_type_not_exist.vv
@@ -0,0 +1,11 @@
+type Integer = i8 | i16 | int | i64
+
+fn main() {
+	fn_with_sum_type_param(1)
+}
+
+fn fn_with_sum_type_param(i Integer) {
+	if i is SomethingThatDontExist {
+		println('It should fail !')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/labelled_break_continue.out b/v_windows/v/old/vlib/v/checker/tests/labelled_break_continue.out
new file mode 100644
index 0000000..caadcfc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/labelled_break_continue.out
@@ -0,0 +1,35 @@
+vlib/v/checker/tests/labelled_break_continue.vv:7:14: error: invalid label name `L2`
+    5 |         i++
+    6 |         for {
+    7 |             if i < 7 {continue L2}
+      |                       ~~~~~~~~
+    8 |             else {break L2}
+    9 |         }
+vlib/v/checker/tests/labelled_break_continue.vv:8:10: error: invalid label name `L2`
+    6 |         for {
+    7 |             if i < 7 {continue L2}
+    8 |             else {break L2}
+      |                   ~~~~~
+    9 |         }
+   10 |     }
+vlib/v/checker/tests/labelled_break_continue.vv:15:14: error: invalid label name `L1`
+   13 |         i = e
+   14 |         for {
+   15 |             if i < 3 {continue L1}
+      |                       ~~~~~~~~
+   16 |             else {break L1}
+   17 |         }
+vlib/v/checker/tests/labelled_break_continue.vv:16:10: error: invalid label name `L1`
+   14 |         for {
+   15 |             if i < 3 {continue L1}
+   16 |             else {break L1}
+      |                   ~~~~~
+   17 |         }
+   18 |     }
+vlib/v/checker/tests/labelled_break_continue.vv:21:11: error: nesting of labelled `for` loops is not supported
+   19 |     // check nested loops (not supported ATM)
+   20 |     L3: for ;; i++ {
+   21 |         L4: for {
+      |                 ^
+   22 |             if i < 17 {continue L3}
+   23 |             else {break L3}
diff --git a/v_windows/v/old/vlib/v/checker/tests/labelled_break_continue.vv b/v_windows/v/old/vlib/v/checker/tests/labelled_break_continue.vv
new file mode 100644
index 0000000..3447ab1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/labelled_break_continue.vv
@@ -0,0 +1,26 @@
+fn main() {
+	mut i := 4
+	// check branching to a later loop
+	L1: for {
+		i++
+		for {
+			if i < 7 {continue L2}
+			else {break L2}
+		}
+	}
+	// check branching to an earlier loop
+	L2: for e in [1,2,3,4] {
+		i = e
+		for {
+			if i < 3 {continue L1}
+			else {break L1}
+		}
+	}
+	// check nested loops (not supported ATM)
+	L3: for ;; i++ {
+		L4: for {
+			if i < 17 {continue L3}
+			else {break L3}
+		}
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_already_locked.out b/v_windows/v/old/vlib/v/checker/tests/lock_already_locked.out
new file mode 100644
index 0000000..29696aa
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_already_locked.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/lock_already_locked.vv:11:3: error: nested `lock`/`rlock` not allowed
+    9 |     }
+   10 |     lock a {
+   11 |         rlock a {
+      |         ~~~~~
+   12 |             a.x++
+   13 |         }
+vlib/v/checker/tests/lock_already_locked.vv:15:10: error: `a` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut argument to print
+   13 |         }
+   14 |     }
+   15 |     println(a.x)
+      |             ^
+   16 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_already_locked.vv b/v_windows/v/old/vlib/v/checker/tests/lock_already_locked.vv
new file mode 100644
index 0000000..7bb6365
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_already_locked.vv
@@ -0,0 +1,16 @@
+struct St {
+mut:
+	x int
+}
+
+fn main() {
+	shared a := &St{
+		x: 5
+	}
+	lock a {
+		rlock a {
+			a.x++
+		}
+	}
+	println(a.x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_already_rlocked.out b/v_windows/v/old/vlib/v/checker/tests/lock_already_rlocked.out
new file mode 100644
index 0000000..b7e3fda
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_already_rlocked.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/lock_already_rlocked.vv:11:3: error: nested `lock`/`rlock` not allowed
+    9 |     }
+   10 |     rlock a {
+   11 |         lock a {
+      |         ~~~~
+   12 |             a.x++
+   13 |         }
+vlib/v/checker/tests/lock_already_rlocked.vv:15:10: error: `a` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut argument to print
+   13 |         }
+   14 |     }
+   15 |     println(a.x)
+      |             ^
+   16 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_already_rlocked.vv b/v_windows/v/old/vlib/v/checker/tests/lock_already_rlocked.vv
new file mode 100644
index 0000000..c8e8236
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_already_rlocked.vv
@@ -0,0 +1,16 @@
+struct St {
+mut:
+	x int
+}
+
+fn main() {
+	shared a := &St{
+		x: 5
+	}
+	rlock a {
+		lock a {
+			a.x++
+		}
+	}
+	println(a.x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_const.out b/v_windows/v/old/vlib/v/checker/tests/lock_const.out
new file mode 100644
index 0000000..2b923da
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_const.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/lock_const.vv:7:8: error: `a` must be declared as `shared` variable to be locked
+    5 | fn main() {
+    6 |     mut c := 0
+    7 |     rlock a {
+      |           ^
+    8 |         c = a
+    9 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_const.vv b/v_windows/v/old/vlib/v/checker/tests/lock_const.vv
new file mode 100644
index 0000000..df16a6a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_const.vv
@@ -0,0 +1,11 @@
+const (
+	a = 5
+)
+
+fn main() {
+	mut c := 0
+	rlock a {
+		c = a
+	}
+	println(c)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_needed.out b/v_windows/v/old/vlib/v/checker/tests/lock_needed.out
new file mode 100644
index 0000000..637cbb9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_needed.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/lock_needed.vv:10:2: error: `abc` is `shared` and needs explicit lock for `v.ast.SelectorExpr`
+    8 |         x: 5
+    9 |     }
+   10 |     abc.x++
+      |     ~~~
+   11 |     println(abc.x)
+   12 | }
+vlib/v/checker/tests/lock_needed.vv:11:10: error: `abc` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut argument to print
+    9 |     }
+   10 |     abc.x++
+   11 |     println(abc.x)
+      |             ~~~
+   12 | }
+   13 |
+vlib/v/checker/tests/lock_needed.vv:25:12: error: `a.st` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut argument to print
+   23 |         }
+   24 |     }
+   25 |     println(a.st.x)
+      |               ~~
+   26 | }
+   27 |
+vlib/v/checker/tests/lock_needed.vv:30:10: error: `a` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut argument to print
+   28 | fn g() {
+   29 |     shared a := []f64{len: 10, init: 7.5}
+   30 |     println(a[3])
+      |             ^
+   31 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_needed.vv b/v_windows/v/old/vlib/v/checker/tests/lock_needed.vv
new file mode 100644
index 0000000..001aa7f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_needed.vv
@@ -0,0 +1,31 @@
+struct St {
+mut:
+	x int
+}
+
+fn main() {
+	shared abc := &St{
+		x: 5
+	}
+	abc.x++
+	println(abc.x)
+}
+
+struct Abc {
+mut:
+	st shared St
+}
+
+fn f() {
+	mut a := Abc{
+		st: St{
+			x: 9
+		}
+	}
+	println(a.st.x)
+}
+
+fn g() {
+	shared a := []f64{len: 10, init: 7.5}
+	println(a[3])
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_nonshared.out b/v_windows/v/old/vlib/v/checker/tests/lock_nonshared.out
new file mode 100644
index 0000000..00a05c2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_nonshared.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/lock_nonshared.vv:10:7: error: `a` must be declared as `shared` variable to be locked
+    8 |         x: 5
+    9 |     }
+   10 |     lock a {
+      |          ^
+   11 |         a.x++
+   12 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/lock_nonshared.vv b/v_windows/v/old/vlib/v/checker/tests/lock_nonshared.vv
new file mode 100644
index 0000000..1524285
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/lock_nonshared.vv
@@ -0,0 +1,14 @@
+struct St {
+mut:
+	x int
+}
+
+fn main() {
+	mut a := &St{
+		x: 5
+	}
+	lock a {
+		a.x++
+	}
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_and_script_err.out b/v_windows/v/old/vlib/v/checker/tests/main_and_script_err.out
new file mode 100644
index 0000000..71b5f75
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_and_script_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/main_and_script_err.vv:1:1: error: function `main` is already defined
+    1 | fn main() {
+      | ^
+    2 |     println('main')
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_and_script_err.vv b/v_windows/v/old/vlib/v/checker/tests/main_and_script_err.vv
new file mode 100644
index 0000000..e746460
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_and_script_err.vv
@@ -0,0 +1,4 @@
+fn main() {
+	println('main')
+}
+println('out')
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_args_err.out b/v_windows/v/old/vlib/v/checker/tests/main_args_err.out
new file mode 100644
index 0000000..ee5f426
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_args_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/main_args_err.vv:1:1: error: function `main` cannot have arguments
+    1 | fn main(a string) {
+      | ~~~~~~~~~~~~~~~~~
+    2 |     println(a)
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_args_err.vv b/v_windows/v/old/vlib/v/checker/tests/main_args_err.vv
new file mode 100644
index 0000000..69c9508
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_args_err.vv
@@ -0,0 +1,3 @@
+fn main(a string) {
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_called_err.out b/v_windows/v/old/vlib/v/checker/tests/main_called_err.out
new file mode 100644
index 0000000..1f1e253
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_called_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/main_called_err.vv:2:2: error: the `main` function cannot be called in the program
+    1 | fn main() {
+    2 |     main()
+      |     ~~~~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_called_err.vv b/v_windows/v/old/vlib/v/checker/tests/main_called_err.vv
new file mode 100644
index 0000000..2be2db1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_called_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	main()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_no_body_err.out b/v_windows/v/old/vlib/v/checker/tests/main_no_body_err.out
new file mode 100644
index 0000000..09e4a9f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_no_body_err.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/main_no_body_err.vv:1:1: error: function `main` must declare a body
+    1 | fn main()
+      | ~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_no_body_err.vv b/v_windows/v/old/vlib/v/checker/tests/main_no_body_err.vv
new file mode 100644
index 0000000..d955fb2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_no_body_err.vv
@@ -0,0 +1 @@
+fn main()
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_return_err.out b/v_windows/v/old/vlib/v/checker/tests/main_return_err.out
new file mode 100644
index 0000000..c9ce435
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_return_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/main_return_err.vv:1:1: error: function `main` cannot return values
+    1 | fn main() f64 {
+      | ~~~~~~~~~~~~~
+    2 |     return 1.23
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/main_return_err.vv b/v_windows/v/old/vlib/v/checker/tests/main_return_err.vv
new file mode 100644
index 0000000..de52fe0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/main_return_err.vv
@@ -0,0 +1,3 @@
+fn main() f64 {
+	return 1.23
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_delete.out b/v_windows/v/old/vlib/v/checker/tests/map_delete.out
new file mode 100644
index 0000000..c3a1822
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_delete.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/map_delete.vv:5:11: error: cannot use `int literal` as `string` in argument 1 to `Map.delete`
+    3 |         '1': 1
+    4 |     }
+    5 |     m.delete(1)
+      |              ^
+    6 |     m.delete(1, 2)
+    7 |     m2 := map{
+vlib/v/checker/tests/map_delete.vv:6:4: error: expected 1 argument, but got 2
+    4 |     }
+    5 |     m.delete(1)
+    6 |     m.delete(1, 2)
+      |       ~~~~~~~~~~~~
+    7 |     m2 := map{
+    8 |         '1': 1
+vlib/v/checker/tests/map_delete.vv:10:2: error: `m2` is immutable, declare it with `mut` to make it mutable
+    8 |         '1': 1
+    9 |     }
+   10 |     m2.delete('1')
+      |     ~~
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_delete.vv b/v_windows/v/old/vlib/v/checker/tests/map_delete.vv
new file mode 100644
index 0000000..26b2606
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_delete.vv
@@ -0,0 +1,11 @@
+fn main() {
+	mut m := map{
+		'1': 1
+	}
+	m.delete(1)
+	m.delete(1, 2)
+	m2 := map{
+		'1': 1
+	}
+	m2.delete('1')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_func_void_return_err.out b/v_windows/v/old/vlib/v/checker/tests/map_func_void_return_err.out
new file mode 100644
index 0000000..943e7b1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_func_void_return_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/map_func_void_return_err.vv:2:22: error: type mismatch, `voids` does not return anything
+    1 | fn main() {
+    2 |     list := [1,2,3].map(voids(it))
+      |                         ~~~~~~~~~
+    3 | }
+    4 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_func_void_return_err.vv b/v_windows/v/old/vlib/v/checker/tests/map_func_void_return_err.vv
new file mode 100644
index 0000000..bd5446e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_func_void_return_err.vv
@@ -0,0 +1,7 @@
+fn main() {
+	list := [1,2,3].map(voids(it))
+}
+
+fn voids(arg int) {
+	println(arg)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_init_invalid_syntax.out b/v_windows/v/old/vlib/v/checker/tests/map_init_invalid_syntax.out
new file mode 100644
index 0000000..e18f40d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_init_invalid_syntax.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/map_init_invalid_syntax.vv:2:10: error: invalid empty map initilization syntax, use e.g. map[string]int{} instead
+    1 | fn main() {
+    2 |     a := map{}
+      |             ~~
+    3 |     println(a)
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_init_invalid_syntax.vv b/v_windows/v/old/vlib/v/checker/tests/map_init_invalid_syntax.vv
new file mode 100644
index 0000000..a976d70
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_init_invalid_syntax.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a := map{}
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_init_key_duplicate_err.out b/v_windows/v/old/vlib/v/checker/tests/map_init_key_duplicate_err.out
new file mode 100644
index 0000000..d560b64
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_init_key_duplicate_err.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/map_init_key_duplicate_err.vv:5:3: error: duplicate key "foo" in map literal
+    3 |         'foo': 'bar'
+    4 |         'abc': 'abc'
+    5 |         'foo': 'bar'
+      |         ~~~~~
+    6 |     }
+    7 |     println(a)
+vlib/v/checker/tests/map_init_key_duplicate_err.vv:9:18: error: duplicate key "2" in map literal
+    7 |     println(a)
+    8 |
+    9 |     _ = map{2:0 3:0 2:0}
+      |                     ^
+   10 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_init_key_duplicate_err.vv b/v_windows/v/old/vlib/v/checker/tests/map_init_key_duplicate_err.vv
new file mode 100644
index 0000000..cd6efe6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_init_key_duplicate_err.vv
@@ -0,0 +1,10 @@
+fn main() {
+	a := map{
+		'foo': 'bar'
+		'abc': 'abc'
+		'foo': 'bar'
+	}
+	println(a)
+
+	_ = map{2:0 3:0 2:0}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_init_wrong_type.out b/v_windows/v/old/vlib/v/checker/tests/map_init_wrong_type.out
new file mode 100644
index 0000000..117e787
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_init_wrong_type.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/map_init_wrong_type.vv:3:18: error: invalid map value: expected `f32`, not `float literal`
+    1 | fn main() {
+    2 |    mut a := map[string]f32{}
+    3 |    a = map{ 'x': 12.3 }
+      |                  ~~~~
+    4 |    _ = map{2:0 3:0 "hi":0}
+    5 |    _ = map{2:0 3:`@` 4:0}
+vlib/v/checker/tests/map_init_wrong_type.vv:4:20: error: invalid map key: expected `int`, not `string`
+    2 |    mut a := map[string]f32{}
+    3 |    a = map{ 'x': 12.3 }
+    4 |    _ = map{2:0 3:0 "hi":0}
+      |                    ~~~~
+    5 |    _ = map{2:0 3:`@` 4:0}
+    6 |   _ = a
+vlib/v/checker/tests/map_init_wrong_type.vv:5:18: error: invalid map value: expected `int`, not `rune`
+    3 |    a = map{ 'x': 12.3 }
+    4 |    _ = map{2:0 3:0 "hi":0}
+    5 |    _ = map{2:0 3:`@` 4:0}
+      |                  ~~~
+    6 |   _ = a
+    7 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_init_wrong_type.vv b/v_windows/v/old/vlib/v/checker/tests/map_init_wrong_type.vv
new file mode 100644
index 0000000..dc41230
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_init_wrong_type.vv
@@ -0,0 +1,7 @@
+fn main() {
+   mut a := map[string]f32{}
+   a = map{ 'x': 12.3 }
+   _ = map{2:0 3:0 "hi":0}
+   _ = map{2:0 3:`@` 4:0}
+  _ = a
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_ops.out b/v_windows/v/old/vlib/v/checker/tests/map_ops.out
new file mode 100644
index 0000000..d30508b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_ops.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/map_ops.vv:3:7: error: invalid key: expected `int`, not `rune`
+    1 | fn test_map() {
+    2 |     mut m := map[int]string
+    3 |     _ = m[`!`]
+      |          ~~~~~
+    4 |     m['hi'] = 8
+    5 |     m[&m] += 4
+vlib/v/checker/tests/map_ops.vv:4:3: error: invalid key: expected `int`, not `string`
+    2 |     mut m := map[int]string
+    3 |     _ = m[`!`]
+    4 |     m['hi'] = 8
+      |      ~~~~~~
+    5 |     m[&m] += 4
+    6 | }
+vlib/v/checker/tests/map_ops.vv:5:3: error: invalid key: expected `int`, not `&map[int]string`
+    3 |     _ = m[`!`]
+    4 |     m['hi'] = 8
+    5 |     m[&m] += 4
+      |      ~~~~
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_ops.vv b/v_windows/v/old/vlib/v/checker/tests/map_ops.vv
new file mode 100644
index 0000000..ac71947
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_ops.vv
@@ -0,0 +1,6 @@
+fn test_map() {
+	mut m := map[int]string
+	_ = m[`!`]
+	m['hi'] = 8
+	m[&m] += 4
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_unknown_value.out b/v_windows/v/old/vlib/v/checker/tests/map_unknown_value.out
new file mode 100644
index 0000000..d5f268b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_unknown_value.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/map_unknown_value.vv:2:23: error: unknown type `DoesNotExist`
+    1 | struct App {
+    2 |     my_map map[string]DoesNotExist
+      |                       ~~~~~~~~~~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/map_unknown_value.vv b/v_windows/v/old/vlib/v/checker/tests/map_unknown_value.vv
new file mode 100644
index 0000000..90cb87d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/map_unknown_value.vv
@@ -0,0 +1,3 @@
+struct App {
+    my_map map[string]DoesNotExist
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_alias_type_err.out b/v_windows/v/old/vlib/v/checker/tests/match_alias_type_err.out
new file mode 100644
index 0000000..49ddf1f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_alias_type_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/match_alias_type_err.vv:13:3: error: cannot match alias type `Stmt` with `SelectStmt`
+   11 | 
+   12 |     match stmt {
+   13 |         SelectStmt { panic('select') }
+      |         ~~~~~~~~~~
+   14 |         else { /* why? */ }
+   15 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_alias_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/match_alias_type_err.vv
new file mode 100644
index 0000000..2673231
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_alias_type_err.vv
@@ -0,0 +1,16 @@
+type Stmt = SelectStmt
+
+struct SelectStmt {}
+
+fn parse(sql string) Stmt {
+	return SelectStmt{}
+}
+
+fn main() {
+	stmt := parse('select 123')
+
+	match stmt {
+		SelectStmt { panic('select') }
+		else { /* why? */ }
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_duplicate_branch.out b/v_windows/v/old/vlib/v/checker/tests/match_duplicate_branch.out
new file mode 100644
index 0000000..11263d5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_duplicate_branch.out
@@ -0,0 +1,42 @@
+vlib/v/checker/tests/match_duplicate_branch.vv:15:3: error: match case `St1` is handled more than once
+   13 |     match i {
+   14 |         St1 { println('St1') }
+   15 |         St1 { println('St1') }
+      |         ~~~
+   16 |         St2 { println('St2') }
+   17 |     }
+vlib/v/checker/tests/match_duplicate_branch.vv:20:3: error: match case `St1` is handled more than once
+   18 |     match i {
+   19 |         St1 { println('St1') }
+   20 |         St1 { println('St1') }
+      |         ~~~
+   21 |         else { println('else') }
+   22 |     }
+vlib/v/checker/tests/match_duplicate_branch.vv:29:3: error: match case `green` is handled more than once
+   27 |         .red { println('red') }
+   28 |         .green { println('green') }
+   29 |         .green { println('green') }
+      |         ~~~~~~
+   30 |         .blue { println('blue') }
+   31 |     }
+vlib/v/checker/tests/match_duplicate_branch.vv:34:3: error: match case `green` is handled more than once
+   32 |     match c {
+   33 |         .red, .green { println('red green') }
+   34 |         .green { println('green') }
+      |         ~~~~~~
+   35 |         else { println('else') }
+   36 |     }
+vlib/v/checker/tests/match_duplicate_branch.vv:43:3: error: match case `2` is handled more than once
+   41 |         1 { println('1') }
+   42 |         2 { println('2') }
+   43 |         2 { println('3') }
+      |         ^
+   44 |         else { println('else') }
+   45 |     }
+vlib/v/checker/tests/match_duplicate_branch.vv:51:3: error: match case `3` is handled more than once
+   49 |     match i {
+   50 |         1...5 { println('1 to 5') }
+   51 |         3 { println('3') }
+      |         ^
+   52 |         else { println('else') }
+   53 |     }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_duplicate_branch.vv b/v_windows/v/old/vlib/v/checker/tests/match_duplicate_branch.vv
new file mode 100644
index 0000000..dd5a92c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_duplicate_branch.vv
@@ -0,0 +1,61 @@
+enum Color {
+	red
+	green
+	blue
+}
+
+struct St1 {}
+struct St2 {}
+
+type St = St1 | St2
+
+fn test_sum_type(i St) {
+	match i {
+		St1 { println('St1') }
+		St1 { println('St1') }
+		St2 { println('St2') }
+	}
+	match i {
+		St1 { println('St1') }
+		St1 { println('St1') }
+		else { println('else') }
+	}
+}
+
+fn test_enum(c Color) {
+	match c {
+		.red { println('red') }
+		.green { println('green') }
+		.green { println('green') }
+		.blue { println('blue') }
+	}
+	match c {
+		.red, .green { println('red green') }
+		.green { println('green') }
+		else { println('else') }
+	}
+}
+
+fn test_int(i int) {
+	match i {
+		1 { println('1') }
+		2 { println('2') }
+		2 { println('3') }
+		else { println('else') }
+	}
+}
+
+fn test_range(i int) {
+	match i {
+		1...5 { println('1 to 5') }
+		3 { println('3') }
+		else { println('else') }
+	}
+}
+
+fn main() {
+	test_sum_type(St1{})
+	test_enum(.red)
+	test_int(2)
+	test_range(4)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_else_last_expr.out b/v_windows/v/old/vlib/v/checker/tests/match_else_last_expr.out
new file mode 100644
index 0000000..c3331f1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_else_last_expr.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/match_else_last_expr.vv:4:3: error: `else` must be the last branch of `match`
+    2 |     match 1 {
+    3 |         1 { println('1') }
+    4 |         else { println('else') }
+      |         ~~~~
+    5 |         4 { println('4') }
+    6 |     }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_else_last_expr.vv b/v_windows/v/old/vlib/v/checker/tests/match_else_last_expr.vv
new file mode 100644
index 0000000..3aa5cc5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_else_last_expr.vv
@@ -0,0 +1,7 @@
+fn main() {
+	match 1 {
+		1 { println('1') }
+		else { println('else') }
+		4 { println('4') }
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_expr_and_expected_type_error.out b/v_windows/v/old/vlib/v/checker/tests/match_expr_and_expected_type_error.out
new file mode 100644
index 0000000..e42355f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_expr_and_expected_type_error.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/match_expr_and_expected_type_error.vv:3:3: error: cannot match `rune` with `string`
+    1 | ch := `a`
+    2 | match ch {
+    3 |   'a' {}
+      |   ~~~
+    4 |   else {}
+    5 | }
+vlib/v/checker/tests/match_expr_and_expected_type_error.vv:9:3: error: cannot match `int` with `string`
+    7 | i := 123
+    8 | match i {
+    9 |   'a' {}
+      |   ~~~
+   10 |   else {}
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_expr_and_expected_type_error.vv b/v_windows/v/old/vlib/v/checker/tests/match_expr_and_expected_type_error.vv
new file mode 100644
index 0000000..ef1e62c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_expr_and_expected_type_error.vv
@@ -0,0 +1,11 @@
+ch := `a`
+match ch {
+  'a' {}
+  else {}
+}
+
+i := 123
+match i {
+  'a' {}
+  else {}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_expr_else.out b/v_windows/v/old/vlib/v/checker/tests/match_expr_else.out
new file mode 100644
index 0000000..cf70833
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_expr_else.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/match_expr_else.vv:5:6: error: match must be exhaustive (add match branches for: `f64` or `else {}` at the end)
+    3 | fn main() {
+    4 |     x := AA('test')
+    5 |     _ = match x {
+      |         ~~~~~~~~~
+    6 |         int {
+    7 |             'int'
+vlib/v/checker/tests/match_expr_else.vv:23:3: error: match expression is exhaustive, `else` is unnecessary
+   21 |             'f64'
+   22 |         }
+   23 |         else {
+      |         ~~~~
+   24 |             'else'
+   25 |         }
+vlib/v/checker/tests/match_expr_else.vv:34:3: error: `else` must be the last branch of `match`
+   32 |             'string'
+   33 |         }
+   34 |         else {
+      |         ~~~~
+   35 |             'else'
+   36 |         }
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_expr_else.vv b/v_windows/v/old/vlib/v/checker/tests/match_expr_else.vv
new file mode 100644
index 0000000..7c5551e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_expr_else.vv
@@ -0,0 +1,41 @@
+type AA = int | string | f64
+
+fn main() {
+	x := AA('test')
+	_ = match x {
+		int {
+			'int'
+		}
+		string {
+			'string'
+		}
+	}
+	_ = match x {
+		int {
+			'int'
+		}
+		string {
+			'string'
+		}
+		f64 {
+			'f64'
+		}
+		else {
+			'else'
+		}
+	}
+	_ = match x {
+		int {
+			'int'
+		}
+		string {
+			'string'
+		}
+		else {
+			'else'
+		}
+		f64 {
+			'f64'
+		}
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_expr_empty_branch.out b/v_windows/v/old/vlib/v/checker/tests/match_expr_empty_branch.out
new file mode 100644
index 0000000..927da5a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_expr_empty_branch.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/match_expr_empty_branch.vv:3:2: error: `match` expression requires an expression as the last statement of every branch
+    1 | _ := match true {
+    2 |     true { 0 }
+    3 |     false {}
+      |     ~~~~~~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_expr_empty_branch.vv b/v_windows/v/old/vlib/v/checker/tests/match_expr_empty_branch.vv
new file mode 100644
index 0000000..2a8650d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_expr_empty_branch.vv
@@ -0,0 +1,4 @@
+_ := match true {
+	true { 0 }
+	false {}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_expr_non_void_stmt_last.out b/v_windows/v/old/vlib/v/checker/tests/match_expr_non_void_stmt_last.out
new file mode 100644
index 0000000..6b5e161
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_expr_non_void_stmt_last.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/match_expr_non_void_stmt_last.vv:9:4: error: `match` expression requires an expression as the last statement of every branch
+    7 |         }
+    8 |         []int {
+    9 |             return arr.str()
+      |             ~~~~~~~~~~~~~~~~
+   10 |         }
+   11 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_expr_non_void_stmt_last.vv b/v_windows/v/old/vlib/v/checker/tests/match_expr_non_void_stmt_last.vv
new file mode 100644
index 0000000..0737152
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_expr_non_void_stmt_last.vv
@@ -0,0 +1,17 @@
+type Arr = []int | []string
+
+fn (arr Arr) str() string {
+	return match arr {
+		[]string {
+			arr.join(' ')
+		}
+		[]int {
+			return arr.str()
+		}
+	}
+}
+
+fn main() {
+	println(Arr([0, 0]))
+	println(Arr(['0', '0']))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_invalid_type.out b/v_windows/v/old/vlib/v/checker/tests/match_invalid_type.out
new file mode 100644
index 0000000..4c6b98b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_invalid_type.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/match_invalid_type.vv:5:3: error: `IoS` has no variant `byte`
+    3 | fn sum() {
+    4 |     match IoS(1) {
+    5 |         byte {
+      |         ~~~~
+    6 |             println('not cool')
+    7 |         }
+vlib/v/checker/tests/match_invalid_type.vv:4:2: error: match must be exhaustive (add match branches for: `int`, `string` or `else {}` at the end)
+    2 | 
+    3 | fn sum() {
+    4 |     match IoS(1) {
+      |     ~~~~~~~~~~~~~~
+    5 |         byte {
+    6 |             println('not cool')
+vlib/v/checker/tests/match_invalid_type.vv:24:3: error: `Cat` doesn't implement method `speak` of interface `Animal`
+   22 |     a := Animal(Dog{})
+   23 |     match a {
+   24 |         Cat {
+      |         ~~~
+   25 |             println('not cool either')
+   26 |         }
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_invalid_type.vv b/v_windows/v/old/vlib/v/checker/tests/match_invalid_type.vv
new file mode 100644
index 0000000..3a5dca6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_invalid_type.vv
@@ -0,0 +1,29 @@
+type IoS = int | string
+
+fn sum() {
+	match IoS(1) {
+		byte {
+			println('not cool')
+		}
+	}
+}
+
+interface Animal {
+	speak()
+}
+
+struct Dog {}
+
+fn (d Dog) speak() {}
+
+struct Cat {}
+
+fn iface() {
+	a := Animal(Dog{})
+	match a {
+		Cat {
+			println('not cool either')
+		}
+		else {}
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_return_mismatch_type_err.out b/v_windows/v/old/vlib/v/checker/tests/match_return_mismatch_type_err.out
new file mode 100644
index 0000000..3a8e8fe
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_return_mismatch_type_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/match_return_mismatch_type_err.vv:4:10: error: return type mismatch, it should be `string`
+    2 |     a := match 1 {
+    3 |         1 { 'aa' }
+    4 |         else { 22 }
+      |                ~~
+    5 |     }
+    6 |     println(a)
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_return_mismatch_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/match_return_mismatch_type_err.vv
new file mode 100644
index 0000000..c422126
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_return_mismatch_type_err.vv
@@ -0,0 +1,7 @@
+fn main() {
+	a := match 1 {
+		1 { 'aa' }
+		else { 22 }
+	}
+	println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_sumtype_multiple_types.out b/v_windows/v/old/vlib/v/checker/tests/match_sumtype_multiple_types.out
new file mode 100644
index 0000000..9f2201f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_sumtype_multiple_types.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/match_sumtype_multiple_types.vv:26:13: error: type `Charlie` has no field or method `char`
+   24 |     match l {
+   25 |         Alfa, Charlie {
+   26 |             assert l.char == `a`
+      |                      ~~~~
+   27 |             assert l.letter() == 'a'
+   28 |         }
+vlib/v/checker/tests/match_sumtype_multiple_types.vv:27:13: error: unknown method: `Charlie.letter`
+   25 |         Alfa, Charlie {
+   26 |             assert l.char == `a`
+   27 |             assert l.letter() == 'a'
+      |                      ~~~~~~~~
+   28 |         }
+   29 |         Bravo {
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_sumtype_multiple_types.vv b/v_windows/v/old/vlib/v/checker/tests/match_sumtype_multiple_types.vv
new file mode 100644
index 0000000..eca5954
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_sumtype_multiple_types.vv
@@ -0,0 +1,33 @@
+struct Alfa {
+	char rune
+}
+
+fn (a Alfa) letter() rune {
+	return a.char
+}
+
+struct Bravo {
+	char rune
+}
+
+fn (b Bravo) letter() rune {
+	return b.char
+}
+
+struct Charlie {}
+
+type NATOAlphabet = Alfa | Bravo | Charlie
+
+fn method_not_exists() {
+	a := Alfa{}
+	l := NATOAlphabet(a)
+	match l {
+		Alfa, Charlie {
+			assert l.char == `a`
+			assert l.letter() == 'a'
+		}
+		Bravo {
+			assert false
+		}
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_undefined_cond.out b/v_windows/v/old/vlib/v/checker/tests/match_undefined_cond.out
new file mode 100644
index 0000000..ddfed08
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_undefined_cond.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/match_undefined_cond.vv:4:15: error: undefined ident: `Asd`
+    2 | 
+    3 | fn main() {
+    4 |     res := match Asd {
+      |                  ~~~
+    5 |         1 { 'foo' }
+    6 |         2 { 'test' }
+vlib/v/checker/tests/match_undefined_cond.vv:5:3: error: cannot match `void` with `int literal`
+    3 | fn main() {
+    4 |     res := match Asd {
+    5 |         1 { 'foo' }
+      |         ^
+    6 |         2 { 'test' }
+    7 |         else { '' }
+vlib/v/checker/tests/match_undefined_cond.vv:6:3: error: cannot match `void` with `int literal`
+    4 |     res := match Asd {
+    5 |         1 { 'foo' }
+    6 |         2 { 'test' }
+      |         ^
+    7 |         else { '' }
+    8 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/match_undefined_cond.vv b/v_windows/v/old/vlib/v/checker/tests/match_undefined_cond.vv
new file mode 100644
index 0000000..952e4b7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/match_undefined_cond.vv
@@ -0,0 +1,10 @@
+type Asd = int
+
+fn main() {
+	res := match Asd {
+		1 { 'foo' }
+		2 { 'test' }
+		else { '' }
+	}
+	_ = res
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_array_slice.out b/v_windows/v/old/vlib/v/checker/tests/method_array_slice.out
new file mode 100644
index 0000000..dde9055
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_array_slice.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/method_array_slice.vv:5:12: error: .slice() is a private method, use `x[start..end]` instead
+    3 | fn main() {
+    4 |     a := os.args.clone()
+    5 |     println(a.slice(1))
+      |               ~~~~~~~~
+    6 |     println(a[1..])
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_array_slice.vv b/v_windows/v/old/vlib/v/checker/tests/method_array_slice.vv
new file mode 100644
index 0000000..cfb77f3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_array_slice.vv
@@ -0,0 +1,7 @@
+import os
+
+fn main() {
+	a := os.args.clone()
+	println(a.slice(1))
+	println(a[1..])
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_generic_infer_err.out b/v_windows/v/old/vlib/v/checker/tests/method_generic_infer_err.out
new file mode 100644
index 0000000..2017a6f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_generic_infer_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/method_generic_infer_err.vv:9:7: error: could not infer generic type `T` in call to `func`
+    7 | fn main() {
+    8 |     data := Data{}
+    9 |     data.func()
+      |          ~~~~~~
+   10 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_generic_infer_err.vv b/v_windows/v/old/vlib/v/checker/tests/method_generic_infer_err.vv
new file mode 100644
index 0000000..226c4c2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_generic_infer_err.vv
@@ -0,0 +1,10 @@
+struct Data {}
+
+fn (_ Data) func<T>() T {
+	return T{}
+}
+
+fn main() {
+	data := Data{}
+	data.func()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_op_alias_err.out b/v_windows/v/old/vlib/v/checker/tests/method_op_alias_err.out
new file mode 100644
index 0000000..195ab56
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_op_alias_err.out
@@ -0,0 +1,42 @@
+vlib/v/checker/tests/method_op_alias_err.vv:4:18: error: expected `Foo` not `Foo2` - both operands must be the same type for operator overloading
+    2 | type Foo2 = string
+    3 |
+    4 | fn (f Foo) + (f1 Foo2) Foo2 {
+      |                  ~~~~
+    5 |     return Foo2(f + f1)
+    6 | }
+vlib/v/checker/tests/method_op_alias_err.vv:5:17: error: infix expr: cannot use `string` (right expression) as `string`
+    3 |
+    4 | fn (f Foo) + (f1 Foo2) Foo2 {
+    5 |     return Foo2(f + f1)
+      |                 ~~~~~~
+    6 | }
+    7 |
+vlib/v/checker/tests/method_op_alias_err.vv:8:1: error: cannot define operator methods on type alias for `string`
+    6 | }
+    7 |
+    8 | fn (f Foo) * (f1 Foo) Foo {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~
+    9 |     return Foo(f + f1)
+   10 | }
+vlib/v/checker/tests/method_op_alias_err.vv:14:6: error: mismatched types `Foo` and `string`
+   12 | fn main() {
+   13 |    mut f := Foo('fg')
+   14 |    f += 'fg'
+      |      ~~
+   15 |    f *= Foo2('2')
+   16 |    f -= Foo('fo')
+vlib/v/checker/tests/method_op_alias_err.vv:15:9: error: cannot assign to `f`: expected `Foo`, not `Foo2`
+   13 |    mut f := Foo('fg')
+   14 |    f += 'fg'
+   15 |    f *= Foo2('2')
+      |         ~~~~~~~~~
+   16 |    f -= Foo('fo')
+   17 |     println(f)
+vlib/v/checker/tests/method_op_alias_err.vv:16:6: error: cannot use operator methods on type alias for `string`
+   14 |    f += 'fg'
+   15 |    f *= Foo2('2')
+   16 |    f -= Foo('fo')
+      |      ~~
+   17 |     println(f)
+   18 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_op_alias_err.vv b/v_windows/v/old/vlib/v/checker/tests/method_op_alias_err.vv
new file mode 100644
index 0000000..d5b4ecd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_op_alias_err.vv
@@ -0,0 +1,18 @@
+type Foo = string 
+type Foo2 = string
+
+fn (f Foo) + (f1 Foo2) Foo2 {
+    return Foo2(f + f1)
+}
+
+fn (f Foo) * (f1 Foo) Foo {
+    return Foo(f + f1)
+}
+
+fn main() {
+   mut f := Foo('fg')
+   f += 'fg'
+   f *= Foo2('2')
+   f -= Foo('fo') 
+    println(f)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_op_err.out b/v_windows/v/old/vlib/v/checker/tests/method_op_err.out
new file mode 100644
index 0000000..547ceea
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_op_err.out
@@ -0,0 +1,69 @@
+vlib/v/checker/tests/method_op_err.vv:11:1: error: operator methods should have exactly 1 argument
+    9 | }
+   10 | 
+   11 | fn (u User) + () {
+      | ~~~~~~~~~~~~~~~~
+   12 | }
+   13 |
+vlib/v/checker/tests/method_op_err.vv:14:18: error: expected `User` not `Foo` - both operands must be the same type for operator overloading
+   12 | }
+   13 | 
+   14 | fn (u User) - (f Foo) User {
+      |                  ~~~
+   15 |     return User{u.a - f.a, u.b-f.a}
+   16 | }
+vlib/v/checker/tests/method_op_err.vv:18:9: error: receiver cannot be `mut` for operator overloading
+   16 | }
+   17 | 
+   18 | fn (mut u User) * (u1 User) User {
+      |         ~~~~~~
+   19 |     return User{}
+   20 | }
+vlib/v/checker/tests/method_op_err.vv:22:1: error: argument cannot be `mut` for operator overloading
+   20 | }
+   21 | 
+   22 | fn (u User) / (mut u1 User) User {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   23 |     return User{}
+   24 | }
+vlib/v/checker/tests/method_op_err.vv:32:13: error: infix expr: cannot use `Foo` (right expression) as `User`
+   30 | fn main() {
+   31 |     println(User{3, 4})
+   32 |     println(User{3, 4} - Foo{3, 3})
+      |             ~~~~~~~~~~~~~~~~~~~~~~
+   33 |     println(User{3, 2} < User{2, 4})
+   34 |     println(User{3, 4} < Foo{3, 4})
+vlib/v/checker/tests/method_op_err.vv:33:13: error: undefined operation `User` < `User`
+   31 |     println(User{3, 4})
+   32 |     println(User{3, 4} - Foo{3, 3})
+   33 |     println(User{3, 2} < User{2, 4})
+      |             ~~~~~~~~~~~~~~~~~~~~~~~
+   34 |     println(User{3, 4} < Foo{3, 4})
+   35 |     mut u := User{3, 4}
+vlib/v/checker/tests/method_op_err.vv:34:13: error: mismatched types `User` and `Foo`
+   32 |     println(User{3, 4} - Foo{3, 3})
+   33 |     println(User{3, 2} < User{2, 4})
+   34 |     println(User{3, 4} < Foo{3, 4})
+      |             ~~~~~~~~~~~~~~~~~~~~~~
+   35 |     mut u := User{3, 4}
+   36 |    _ = u
+vlib/v/checker/tests/method_op_err.vv:37:10: error: cannot assign to `u`: expected `User`, not `int literal`
+   35 |     mut u := User{3, 4}
+   36 |    _ = u
+   37 |     u += 12
+      |          ~~
+   38 |     u %= User{1, 3}
+   39 |     u += User{2, 3}
+vlib/v/checker/tests/method_op_err.vv:38:5: error: operator %= not defined on left operand type `User`
+   36 |    _ = u
+   37 |     u += 12
+   38 |     u %= User{1, 3}
+      |     ^
+   39 |     u += User{2, 3}
+   40 | }
+vlib/v/checker/tests/method_op_err.vv:39:7: error: operator `+` must return `User` to be used as an assignment operator
+   37 |     u += 12
+   38 |     u %= User{1, 3}
+   39 |     u += User{2, 3}
+      |       ~~
+   40 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_op_err.vv b/v_windows/v/old/vlib/v/checker/tests/method_op_err.vv
new file mode 100644
index 0000000..24a82dd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_op_err.vv
@@ -0,0 +1,40 @@
+struct User {
+    a int
+    b int
+}
+
+struct Foo {
+    a int
+    b int
+}
+
+fn (u User) + () {
+}
+
+fn (u User) - (f Foo) User {
+    return User{u.a - f.a, u.b-f.a}
+}
+
+fn (mut u User) * (u1 User) User {
+    return User{}
+}
+
+fn (u User) / (mut u1 User) User {
+    return User{}
+}
+
+fn (u User) + (u1 User) Foo {
+    return Foo{a: u.a + u1.a, b: u.b + u1.b}
+}
+
+fn main() {
+    println(User{3, 4})
+    println(User{3, 4} - Foo{3, 3})
+    println(User{3, 2} < User{2, 4})
+    println(User{3, 4} < Foo{3, 4})
+    mut u := User{3, 4}
+   _ = u
+    u += 12
+    u %= User{1, 3}
+    u += User{2, 3}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_wrong_arg_type.out b/v_windows/v/old/vlib/v/checker/tests/method_wrong_arg_type.out
new file mode 100644
index 0000000..c5175b3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_wrong_arg_type.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/method_wrong_arg_type.vv:10:9: error: cannot use `MyEnum` as `string` in argument 1 to `Sss.info`
+    8 |     e := MyEnum.x
+    9 |     s := Sss{}
+   10 |     s.info(e)
+      |            ^
+   11 | }
+   12 |
+vlib/v/checker/tests/method_wrong_arg_type.vv:18:8: error: cannot use `int` as `&Sss` in argument 1 to `Sss.ptr`
+   16 |     s := Sss{}
+   17 |     v := 4
+   18 |     s.ptr(v)
+      |           ^
+   19 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/method_wrong_arg_type.vv b/v_windows/v/old/vlib/v/checker/tests/method_wrong_arg_type.vv
new file mode 100644
index 0000000..d44a4cd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/method_wrong_arg_type.vv
@@ -0,0 +1,19 @@
+enum MyEnum { x y z }
+pub fn (e MyEnum) str() string { return int(e).str() }
+
+struct Sss { }
+fn (s Sss) info(msg string) { println(msg) }
+
+fn enum_str() {
+	e := MyEnum.x
+	s := Sss{}
+	s.info(e)
+}
+
+fn (s Sss) ptr(p &Sss) {}
+
+fn ptr_arg() {
+	s := Sss{}
+	v := 4
+	s.ptr(v)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/minus_op_wrong_type_err.out b/v_windows/v/old/vlib/v/checker/tests/minus_op_wrong_type_err.out
new file mode 100644
index 0000000..b6895aa
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/minus_op_wrong_type_err.out
@@ -0,0 +1,62 @@
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:10:10: error: mismatched types `Aaa` and `int literal`
+    8 |
+    9 | fn main() {
+   10 |     println(Aaa{} - 10)
+      |             ~~~~~~~~~~
+   11 |     println(10 - Aaa{})
+   12 |     println([1, 2, 3] - 10)
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:11:10: error: mismatched types `int literal` and `Aaa`
+    9 | fn main() {
+   10 |     println(Aaa{} - 10)
+   11 |     println(10 - Aaa{})
+      |             ~~~~~~~~~~
+   12 |     println([1, 2, 3] - 10)
+   13 |     println(10 - [1, 2, 3])
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:12:10: error: mismatched types `[]int` and `int literal`
+   10 |     println(Aaa{} - 10)
+   11 |     println(10 - Aaa{})
+   12 |     println([1, 2, 3] - 10)
+      |             ~~~~~~~~~~~~~~
+   13 |     println(10 - [1, 2, 3])
+   14 |     a := map[string]int{}
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:13:10: error: mismatched types `int literal` and `[]int`
+   11 |     println(10 - Aaa{})
+   12 |     println([1, 2, 3] - 10)
+   13 |     println(10 - [1, 2, 3])
+      |             ~~~~~~~~~~~~~~
+   14 |     a := map[string]int{}
+   15 |     println(a - 10)
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:15:10: error: mismatched types `map[string]int` and `int literal`
+   13 |     println(10 - [1, 2, 3])
+   14 |     a := map[string]int{}
+   15 |     println(a - 10)
+      |             ~~~~~~
+   16 |     println(10 - a)
+   17 |     println(-Aaa{})
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:16:10: error: mismatched types `int literal` and `map[string]int`
+   14 |     a := map[string]int{}
+   15 |     println(a - 10)
+   16 |     println(10 - a)
+      |             ~~~~~~
+   17 |     println(-Aaa{})
+   18 |     println(-a)
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:17:10: error: - operator can only be used with numeric types
+   15 |     println(a - 10)
+   16 |     println(10 - a)
+   17 |     println(-Aaa{})
+      |             ^
+   18 |     println(-a)
+   19 |     println(-Color.red)
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:18:10: error: - operator can only be used with numeric types
+   16 |     println(10 - a)
+   17 |     println(-Aaa{})
+   18 |     println(-a)
+      |             ^
+   19 |     println(-Color.red)
+   20 | }
+vlib/v/checker/tests/minus_op_wrong_type_err.vv:19:10: error: - operator can only be used with numeric types
+   17 |     println(-Aaa{})
+   18 |     println(-a)
+   19 |     println(-Color.red)
+      |             ^
+   20 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/minus_op_wrong_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/minus_op_wrong_type_err.vv
new file mode 100644
index 0000000..e015064
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/minus_op_wrong_type_err.vv
@@ -0,0 +1,20 @@
+struct Aaa {}
+
+enum Color {
+	red
+	green
+	blue
+}
+
+fn main() {
+	println(Aaa{} - 10)
+	println(10 - Aaa{})
+	println([1, 2, 3] - 10)
+	println(10 - [1, 2, 3])
+	a := map[string]int{}
+	println(a - 10)
+	println(10 - a)
+	println(-Aaa{})
+	println(-a)
+	println(-Color.red)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/mismatched_ptr_op_ptr.out b/v_windows/v/old/vlib/v/checker/tests/mismatched_ptr_op_ptr.out
new file mode 100644
index 0000000..a1a1d8a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mismatched_ptr_op_ptr.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/mismatched_ptr_op_ptr.vv:5:17: error: mismatched types `&string` and `string`
+    3 |     unsafe {
+    4 |         b := &a
+    5 |         println(b+*b)
+      |                 ~~~
+    6 |         println(b+b)
+    7 |     }
+vlib/v/checker/tests/mismatched_ptr_op_ptr.vv:6:17: error: invalid operator `+` to `&string` and `&string`
+    4 |         b := &a
+    5 |         println(b+*b)
+    6 |         println(b+b)
+      |                 ~~~
+    7 |     }
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/mismatched_ptr_op_ptr.vv b/v_windows/v/old/vlib/v/checker/tests/mismatched_ptr_op_ptr.vv
new file mode 100644
index 0000000..21a859d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mismatched_ptr_op_ptr.vv
@@ -0,0 +1,8 @@
+fn main() {
+    a := '1'
+    unsafe {
+        b := &a
+        println(b+*b)
+        println(b+b)
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_1.out b/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_1.out
new file mode 100644
index 0000000..c6dc4b2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_1.out
@@ -0,0 +1 @@
+builder error: Header file <missing/folder/header1.h>, needed for module `main` was not found. Please install the corresponding development headers.
diff --git a/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_1.vv b/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_1.vv
new file mode 100644
index 0000000..d8bdb47
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_1.vv
@@ -0,0 +1,6 @@
+module main
+
+// The following header file is intentionally missing.
+// The #include does not have the optional explanation part
+// after a `#` sign:
+#include <missing/folder/header1.h>
diff --git a/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.out b/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.out
new file mode 100644
index 0000000..176ee7b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.out
@@ -0,0 +1 @@
+builder error: Header file <missing/folder/header.h>, needed for module `main` was not found. Please install missing C library.
diff --git a/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.vv b/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.vv
new file mode 100644
index 0000000..a76cc0b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.vv
@@ -0,0 +1,6 @@
+module main
+
+// The following header file is intentionally missing.
+// The part after `#` is an explanation message, that V will
+// show, when it is not found:
+#include <missing/folder/header.h> # Please install missing C library
diff --git a/v_windows/v/old/vlib/v/checker/tests/mod_op_wrong_type_err.out b/v_windows/v/old/vlib/v/checker/tests/mod_op_wrong_type_err.out
new file mode 100644
index 0000000..6ae53be
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mod_op_wrong_type_err.out
@@ -0,0 +1,56 @@
+vlib/v/checker/tests/mod_op_wrong_type_err.vv:3:10: error: float modulo not allowed, use math.fmod() instead
+    1 | struct Aaa{}
+    2 | fn main() {
+    3 |     println(0.5 % 1)
+      |             ~~~
+    4 |     println(1 % 0.5)
+    5 |     println([1,2,3] % 1)
+vlib/v/checker/tests/mod_op_wrong_type_err.vv:4:14: error: float modulo not allowed, use math.fmod() instead
+    2 | fn main() {
+    3 |     println(0.5 % 1)
+    4 |     println(1 % 0.5)
+      |                 ~~~
+    5 |     println([1,2,3] % 1)
+    6 |     println(1 % [1,2,3])
+vlib/v/checker/tests/mod_op_wrong_type_err.vv:5:10: error: mismatched types `[]int` and `int literal`
+    3 |     println(0.5 % 1)
+    4 |     println(1 % 0.5)
+    5 |     println([1,2,3] % 1)
+      |             ~~~~~~~~~~~
+    6 |     println(1 % [1,2,3])
+    7 |     a := Aaa{}
+vlib/v/checker/tests/mod_op_wrong_type_err.vv:6:10: error: mismatched types `int literal` and `[]int`
+    4 |     println(1 % 0.5)
+    5 |     println([1,2,3] % 1)
+    6 |     println(1 % [1,2,3])
+      |             ~~~~~~~~~~~
+    7 |     a := Aaa{}
+    8 |     println(a % 1)
+vlib/v/checker/tests/mod_op_wrong_type_err.vv:8:10: error: mismatched types `Aaa` and `int literal`
+    6 |     println(1 % [1,2,3])
+    7 |     a := Aaa{}
+    8 |     println(a % 1)
+      |             ~~~~~
+    9 |     println(1 % a)
+   10 |     b := map[string]int
+vlib/v/checker/tests/mod_op_wrong_type_err.vv:9:10: error: mismatched types `int literal` and `Aaa`
+    7 |     a := Aaa{}
+    8 |     println(a % 1)
+    9 |     println(1 % a)
+      |             ~~~~~
+   10 |     b := map[string]int
+   11 |     println(b % 1)
+vlib/v/checker/tests/mod_op_wrong_type_err.vv:11:10: error: mismatched types `map[string]int` and `int literal`
+    9 |     println(1 % a)
+   10 |     b := map[string]int
+   11 |     println(b % 1)
+      |             ~~~~~
+   12 |     println(1 % b)
+   13 | }
+vlib/v/checker/tests/mod_op_wrong_type_err.vv:12:10: error: mismatched types `int literal` and `map[string]int`
+   10 |     b := map[string]int
+   11 |     println(b % 1)
+   12 |     println(1 % b)
+      |             ~~~~~
+   13 | }
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/mod_op_wrong_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/mod_op_wrong_type_err.vv
new file mode 100644
index 0000000..b699714
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mod_op_wrong_type_err.vv
@@ -0,0 +1,13 @@
+struct Aaa{}
+fn main() {
+	println(0.5 % 1)
+	println(1 % 0.5)
+	println([1,2,3] % 1)
+	println(1 % [1,2,3])
+	a := Aaa{}
+	println(a % 1)
+	println(1 % a)
+	b := map[string]int
+	println(b % 1)
+	println(1 % b)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/modify_const_with_ref.out b/v_windows/v/old/vlib/v/checker/tests/modify_const_with_ref.out
new file mode 100644
index 0000000..c54a42d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/modify_const_with_ref.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/modify_const_with_ref.vv:11:11: error: `constant` is immutable, cannot have a mutable reference to it
+    9 |     mut unused_var := Foo{}
+   10 |     unused_var = Foo{}
+   11 |     mut c := &constant
+      |              ^
+   12 |     c.value = 200
+   13 | }
+vlib/v/checker/tests/modify_const_with_ref.vv:9:6: error: unused variable: `unused_var`
+    7 | 
+    8 | fn main() {
+    9 |     mut unused_var := Foo{}
+      |         ~~~~~~~~~~
+   10 |     unused_var = Foo{}
+   11 |     mut c := &constant
diff --git a/v_windows/v/old/vlib/v/checker/tests/modify_const_with_ref.vv b/v_windows/v/old/vlib/v/checker/tests/modify_const_with_ref.vv
new file mode 100644
index 0000000..872460e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/modify_const_with_ref.vv
@@ -0,0 +1,13 @@
+struct Foo {
+mut:
+	value int
+}
+
+const constant = Foo{ 100 }
+
+fn main() {
+	mut unused_var := Foo{}
+	unused_var = Foo{}
+	mut c := &constant
+	c.value = 200
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/module_not_at_same_line_err.out b/v_windows/v/old/vlib/v/checker/tests/module_not_at_same_line_err.out
new file mode 100644
index 0000000..6efd5f2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/module_not_at_same_line_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/module_not_at_same_line_err.vv:2:1: error: `module` and `main` must be at same line
+    1 | module
+    2 | main
+      | ~~~~
+    3 | fn main() {
+    4 |     println('hello, world')
diff --git a/v_windows/v/old/vlib/v/checker/tests/module_not_at_same_line_err.vv b/v_windows/v/old/vlib/v/checker/tests/module_not_at_same_line_err.vv
new file mode 100644
index 0000000..a0e52f9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/module_not_at_same_line_err.vv
@@ -0,0 +1,5 @@
+module
+main
+fn main() {
+	println('hello, world')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore.out b/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore.out
new file mode 100644
index 0000000..a0cc315
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/modules/module_alias_started_with_underscore/main.v:3:1: error: module alias `_` cannot start with `_`
+    1 | module main
+    2 | 
+    3 | import underscore as _
+      | ~~~~~~~~~~~~~~~~~~~~~~
+    4 | 
+    5 | fn main() {
diff --git a/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore/main.v b/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore/main.v
new file mode 100644
index 0000000..39f80a1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore/main.v
@@ -0,0 +1,7 @@
+module main
+
+import underscore as _
+
+fn main() {
+	_.foo()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore/underscore.v b/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore/underscore.v
new file mode 100644
index 0000000..ec83c1c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/modules/module_alias_started_with_underscore/underscore.v
@@ -0,0 +1,5 @@
+module underscore
+
+pub fn foo() {
+	println('bar')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type.out b/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type.out
new file mode 100644
index 0000000..dbdf6a5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/modules/overload_return_type/main.v:14:8: error: cannot assign to `two`: expected `point.Point`, not `int`
+   12 |         y: 1
+   13 |     }
+   14 |     two = one + two
+      |           ~~~~~~~~~
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type/main.v b/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type/main.v
new file mode 100644
index 0000000..b682c49
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type/main.v
@@ -0,0 +1,15 @@
+module main
+
+import point { Point }
+
+fn main() {
+	one := Point{
+		x: 1
+		y: 2
+	}
+	mut two := Point{
+		x: 5
+		y: 1
+	}
+	two = one + two
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type/point.v b/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type/point.v
new file mode 100644
index 0000000..a26932b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/modules/overload_return_type/point.v
@@ -0,0 +1,11 @@
+module point
+
+pub struct Point {
+mut:
+	x int
+	y int
+}
+
+pub fn (a Point) + (b Point) int {
+	return a.x + b.x
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/mul_op_wrong_type_err.out b/v_windows/v/old/vlib/v/checker/tests/mul_op_wrong_type_err.out
new file mode 100644
index 0000000..6bd5ff9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mul_op_wrong_type_err.out
@@ -0,0 +1,57 @@
+vlib/v/checker/tests/mul_op_wrong_type_err.vv:5:13: error: mismatched types `Aaa` and `int literal`
+    3 | struct Aaa{}
+    4 | fn main() {
+    5 |     println(Aaa{} * 10)
+      |             ~~~~~~~~~~
+    6 |     println(10 * Aaa{})
+    7 |     println([1,2,3] * 10)
+vlib/v/checker/tests/mul_op_wrong_type_err.vv:6:13: error: mismatched types `int literal` and `Aaa`
+    4 | fn main() {
+    5 |     println(Aaa{} * 10)
+    6 |     println(10 * Aaa{})
+      |             ~~~~~~~~~~
+    7 |     println([1,2,3] * 10)
+    8 |     println(10 * [1,2,3])
+vlib/v/checker/tests/mul_op_wrong_type_err.vv:7:13: error: mismatched types `[]int` and `int literal`
+    5 |     println(Aaa{} * 10)
+    6 |     println(10 * Aaa{})
+    7 |     println([1,2,3] * 10)
+      |             ~~~~~~~~~~~~
+    8 |     println(10 * [1,2,3])
+    9 |     a := map[string]int
+vlib/v/checker/tests/mul_op_wrong_type_err.vv:8:13: error: mismatched types `int literal` and `[]int`
+    6 |     println(10 * Aaa{})
+    7 |     println([1,2,3] * 10)
+    8 |     println(10 * [1,2,3])
+      |             ~~~~~~~~~~~~
+    9 |     a := map[string]int
+   10 |     println(a * 10)
+vlib/v/checker/tests/mul_op_wrong_type_err.vv:10:13: error: mismatched types `map[string]int` and `int literal`
+    8 |     println(10 * [1,2,3])
+    9 |     a := map[string]int
+   10 |     println(a * 10)
+      |             ~~~~~~
+   11 |     println(10 * a)
+   12 |     c1 := cmplx.complex(1,-2)
+vlib/v/checker/tests/mul_op_wrong_type_err.vv:11:13: error: mismatched types `int literal` and `map[string]int`
+    9 |     a := map[string]int
+   10 |     println(a * 10)
+   11 |     println(10 * a)
+      |             ~~~~~~
+   12 |     c1 := cmplx.complex(1,-2)
+   13 |     c2 := c1 * 2.0
+vlib/v/checker/tests/mul_op_wrong_type_err.vv:13:8: error: infix expr: cannot use `float literal` (right expression) as `math.complex.Complex`
+   11 |     println(10 * a)
+   12 |     c1 := cmplx.complex(1,-2)
+   13 |     c2 := c1 * 2.0
+      |           ~~~~~~~~
+   14 |     println(c2)
+   15 |     c3 := 2.0 * c1
+vlib/v/checker/tests/mul_op_wrong_type_err.vv:15:8: error: infix expr: cannot use `math.complex.Complex` (right expression) as `float literal`
+   13 |     c2 := c1 * 2.0
+   14 |     println(c2)
+   15 |     c3 := 2.0 * c1
+      |           ~~~~~~~~
+   16 |     println(c3)
+   17 | }
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/mul_op_wrong_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/mul_op_wrong_type_err.vv
new file mode 100644
index 0000000..a1e3394
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mul_op_wrong_type_err.vv
@@ -0,0 +1,17 @@
+import math
+import math.complex as cmplx
+struct Aaa{}
+fn main() {
+    println(Aaa{} * 10)
+    println(10 * Aaa{})
+    println([1,2,3] * 10)
+    println(10 * [1,2,3])
+	a := map[string]int
+    println(a * 10)
+    println(10 * a)
+	c1 := cmplx.complex(1,-2)
+	c2 := c1 * 2.0
+	println(c2)
+	c3 := 2.0 * c1
+	println(c3)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/multi_const_field_name_duplicate_err.out b/v_windows/v/old/vlib/v/checker/tests/multi_const_field_name_duplicate_err.out
new file mode 100644
index 0000000..731b9f7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/multi_const_field_name_duplicate_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/multi_const_field_name_duplicate_err.vv:2:8: error: duplicate const `aaa`
+    1 | const (aaa = 1)
+    2 | const (aaa = 2)
+      |        ~~~
+    3 | fn main() {
+    4 |     println(aaa)
diff --git a/v_windows/v/old/vlib/v/checker/tests/multi_const_field_name_duplicate_err.vv b/v_windows/v/old/vlib/v/checker/tests/multi_const_field_name_duplicate_err.vv
new file mode 100644
index 0000000..883abac
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/multi_const_field_name_duplicate_err.vv
@@ -0,0 +1,5 @@
+const (aaa = 1)
+const (aaa = 2)
+fn main() {
+	println(aaa)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/multi_names_err.out b/v_windows/v/old/vlib/v/checker/tests/multi_names_err.out
new file mode 100644
index 0000000..a022208
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/multi_names_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/multi_names_err.vv:2:4: error: unexpected name `a`
+    1 | fn main() {
+    2 |     a a a a := 1
+      |       ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/multi_names_err.vv b/v_windows/v/old/vlib/v/checker/tests/multi_names_err.vv
new file mode 100644
index 0000000..cff1441
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/multi_names_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	a a a a := 1
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/multi_value_method_err.out b/v_windows/v/old/vlib/v/checker/tests/multi_value_method_err.out
new file mode 100644
index 0000000..f5be76a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/multi_value_method_err.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/multi_value_method_err.vv:1:7: error: cannot define method on multi-value
+    1 | fn (v (int, int)) f() {}
+      |       ~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/multi_value_method_err.vv b/v_windows/v/old/vlib/v/checker/tests/multi_value_method_err.vv
new file mode 100644
index 0000000..a84f0b6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/multi_value_method_err.vv
@@ -0,0 +1 @@
+fn (v (int, int)) f() {}
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_arg.out b/v_windows/v/old/vlib/v/checker/tests/mut_arg.out
new file mode 100644
index 0000000..f18c285
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_arg.out
@@ -0,0 +1,25 @@
+vlib/v/checker/tests/mut_arg.vv:6:3: error: `f` parameter `par` is `mut`, you need to provide `mut` e.g. `mut arg1`
+    4 | }
+    5 |
+    6 | f([3,4])
+      |   ~~~~~
+    7 | mut a := [1,2]
+    8 | f(a)
+vlib/v/checker/tests/mut_arg.vv:8:3: error: `f` parameter `par` is `mut`, you need to provide `mut` e.g. `mut arg1`
+    6 | f([3,4])
+    7 | mut a := [1,2]
+    8 | f(a)
+      |   ^
+    9 |
+   10 | g(mut [3,4])
+vlib/v/checker/tests/mut_arg.vv:10:7: error: array literal can not be modified
+    8 | f(a)
+    9 |
+   10 | g(mut [3,4])
+      |       ~~~~~
+   11 | g(mut a)
+vlib/v/checker/tests/mut_arg.vv:11:7: error: `g` parameter `par` is not `mut`, `mut` is not needed`
+    9 |
+   10 | g(mut [3,4])
+   11 | g(mut a)
+      |       ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_arg.vv b/v_windows/v/old/vlib/v/checker/tests/mut_arg.vv
new file mode 100644
index 0000000..0a2afdd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_arg.vv
@@ -0,0 +1,11 @@
+fn f(mut par []int) {
+}
+fn g(par []int) {
+}
+
+f([3,4])
+mut a := [1,2]
+f(a)
+
+g(mut [3,4])
+g(mut a)
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_args_warning.out b/v_windows/v/old/vlib/v/checker/tests/mut_args_warning.out
new file mode 100644
index 0000000..726f4b8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_args_warning.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/mut_args_warning.vv:1:8: warning: use `mut f Foo` instead of `f mut Foo`
+    1 | fn f(x mut []int) { x[0] = 1 }
+      |        ~~~
+    2 | fn main() {
+    3 |     mut x := [0]
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_args_warning.vv b/v_windows/v/old/vlib/v/checker/tests/mut_args_warning.vv
new file mode 100644
index 0000000..c29b27d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_args_warning.vv
@@ -0,0 +1,5 @@
+fn f(x mut []int) { x[0] = 1 }
+fn main() {
+	mut x := [0]
+	f(mut x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_array_get_element_address_err.out b/v_windows/v/old/vlib/v/checker/tests/mut_array_get_element_address_err.out
new file mode 100644
index 0000000..a98d17b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_array_get_element_address_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/mut_array_get_element_address_err.vv:3:20: error: cannot take the address of mutable array elements outside unsafe blocks
+    1 | fn main() {
+    2 |     mut arr_int := [int(23), 45, 7, 8]
+    3 |     ele := &arr_int[1]
+      |                    ~~~
+    4 |     println(ele)
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_array_get_element_address_err.vv b/v_windows/v/old/vlib/v/checker/tests/mut_array_get_element_address_err.vv
new file mode 100644
index 0000000..1afbcb3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_array_get_element_address_err.vv
@@ -0,0 +1,5 @@
+fn main() {
+    mut arr_int := [int(23), 45, 7, 8]
+    ele := &arr_int[1]
+    println(ele)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_int.out b/v_windows/v/old/vlib/v/checker/tests/mut_int.out
new file mode 100644
index 0000000..20a092c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_int.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/mut_int.vv:1:14: error: mutable arguments are only allowed for arrays, interfaces, maps, pointers, structs or their aliases
+return values instead: `fn foo(mut n int) {` => `fn foo(n int) int {`
+    1 | fn foo(mut x int) {
+      |              ~~~
+    2 | }
+    3 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_int.vv b/v_windows/v/old/vlib/v/checker/tests/mut_int.vv
new file mode 100644
index 0000000..a268c5a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_int.vv
@@ -0,0 +1,5 @@
+fn foo(mut x int) {
+}
+
+fn main() {
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_map_get_value_address_err.out b/v_windows/v/old/vlib/v/checker/tests/mut_map_get_value_address_err.out
new file mode 100644
index 0000000..297c228
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_map_get_value_address_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/mut_map_get_value_address_err.vv:3:12: error: cannot take the address of map values
+    1 | fn main() {
+    2 |     mut m := map{'key' : 3}
+    3 |     a := &m['key']
+      |            ~~~~~~~
+    4 |     println(a)
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_map_get_value_address_err.vv b/v_windows/v/old/vlib/v/checker/tests/mut_map_get_value_address_err.vv
new file mode 100644
index 0000000..46e5b77
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_map_get_value_address_err.vv
@@ -0,0 +1,5 @@
+fn main() {
+    mut m := map{'key' : 3}
+    a := &m['key']
+    println(a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_receiver.out b/v_windows/v/old/vlib/v/checker/tests/mut_receiver.out
new file mode 100644
index 0000000..fb160a4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_receiver.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/mut_receiver.vv:5:4: warning: use `(mut f Foo)` instead of `(f mut Foo)`
+    3 |     name string
+    4 | }
+    5 | fn (f mut Foo) info() {
+      |    ~~~~~~~~~~~
+    6 |     f.name = 'foo'
+    7 | }
+vlib/v/checker/tests/mut_receiver.vv:8:4: error: use `(mut f Foo)` or `(f &Foo)` instead of `(mut f &Foo)`
+    6 |     f.name = 'foo'
+    7 | }
+    8 | fn (mut f &Foo) info2() {
+      |    ~~~~~~~~~~~~
+    9 |     f.name = 'foo'
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_receiver.vv b/v_windows/v/old/vlib/v/checker/tests/mut_receiver.vv
new file mode 100644
index 0000000..fae05df
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_receiver.vv
@@ -0,0 +1,13 @@
+struct Foo{
+mut:
+	name string
+}
+fn (f mut Foo) info() {
+	f.name = 'foo'
+}
+fn (mut f &Foo) info2() {
+	f.name = 'foo'
+}
+fn main() {
+	println('hello, world')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_receiver_lit.out b/v_windows/v/old/vlib/v/checker/tests/mut_receiver_lit.out
new file mode 100644
index 0000000..e0cd490
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_receiver_lit.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/mut_receiver_lit.vv:10:1: error: cannot pass expression as `mut`
+    8 | }
+    9 | 
+   10 | Box{}.set(0)
+      | ~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/mut_receiver_lit.vv b/v_windows/v/old/vlib/v/checker/tests/mut_receiver_lit.vv
new file mode 100644
index 0000000..e015e71
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/mut_receiver_lit.vv
@@ -0,0 +1,10 @@
+struct Box {
+mut:
+	value int
+}
+
+fn (mut box Box) set(value int) {
+	box.value = value
+}
+
+Box{}.set(0)
diff --git a/v_windows/v/old/vlib/v/checker/tests/negative_assign_to_unsigned.out b/v_windows/v/old/vlib/v/checker/tests/negative_assign_to_unsigned.out
new file mode 100644
index 0000000..1927447
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/negative_assign_to_unsigned.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/negative_assign_to_unsigned.vv:3:9: error: Cannot assign negative value to unsigned integer type
+    1 | fn main() {
+    2 |     mut u := u32(10)
+    3 |     u = -10
+      |         ~~~
+    4 |     eprintln(u)
+    5 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/negative_assign_to_unsigned.vv b/v_windows/v/old/vlib/v/checker/tests/negative_assign_to_unsigned.vv
new file mode 100644
index 0000000..da7646d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/negative_assign_to_unsigned.vv
@@ -0,0 +1,5 @@
+fn main() {
+    mut u := u32(10)
+    u = -10
+    eprintln(u)
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/nested_aliases.out b/v_windows/v/old/vlib/v/checker/tests/nested_aliases.out
new file mode 100644
index 0000000..da93210
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/nested_aliases.out
@@ -0,0 +1,4 @@
+vlib/v/checker/tests/nested_aliases.vv:2:16: error: type `MyInt` is an alias, use the original alias type `int` instead
+    1 | type MyInt = int
+    2 | type MyMyInt = MyInt
+      |                ~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/nested_aliases.vv b/v_windows/v/old/vlib/v/checker/tests/nested_aliases.vv
new file mode 100644
index 0000000..a21d0d3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/nested_aliases.vv
@@ -0,0 +1,2 @@
+type MyInt = int
+type MyMyInt = MyInt
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_heap_struct.out b/v_windows/v/old/vlib/v/checker/tests/no_heap_struct.out
new file mode 100644
index 0000000..8a996a1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_heap_struct.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/no_heap_struct.vv:13:6: error: `x` cannot be assigned outside `unsafe` blocks as it might refer to an object stored on stack. Consider declaring `Abc` as `[heap]`.
+   11 | fn f(x &Abc) St {
+   12 |     s := St{
+   13 |         a: x
+      |            ^
+   14 |     }
+   15 |     return s
+vlib/v/checker/tests/no_heap_struct.vv:19:9: error: `x` cannot be returned outside `unsafe` blocks as it might refer to an object stored on stack. Consider declaring `Abc` as `[heap]`.
+   17 | 
+   18 | fn g(mut x Abc) &Abc {
+   19 |     return x
+      |            ^
+   20 | }
+   21 |
+vlib/v/checker/tests/no_heap_struct.vv:23:7: error: `x` cannot be assigned outside `unsafe` blocks as it might refer to an object stored on stack. Consider declaring `Abc` as `[heap]`.
+   21 | 
+   22 | fn h(x &Abc) &Abc {
+   23 |     y := x
+      |          ^
+   24 |     return y
+   25 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_heap_struct.vv b/v_windows/v/old/vlib/v/checker/tests/no_heap_struct.vv
new file mode 100644
index 0000000..ce1d474
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_heap_struct.vv
@@ -0,0 +1,25 @@
+struct Abc {
+mut:
+	n int
+}
+
+struct St {
+mut:
+	a &Abc
+}
+
+fn f(x &Abc) St {
+	s := St{
+		a: x
+	}
+	return s
+}
+
+fn g(mut x Abc) &Abc {
+	return x
+}
+
+fn h(x &Abc) &Abc {
+	y := x
+	return y
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_a.out b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_a.out
new file mode 100644
index 0000000..e01c3a7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_a.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/no_interface_instantiation_a.vv:4:9: error: cannot instantiate interface `Speaker`
+    2 |
+    3 | fn main() {
+    4 |     _ = Speaker{}
+      |         ~~~~~~~~~
+    5 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_a.vv b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_a.vv
new file mode 100644
index 0000000..1d98644
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_a.vv
@@ -0,0 +1,5 @@
+interface Speaker {}
+
+fn main() {
+    _ = Speaker{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_b.out b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_b.out
new file mode 100644
index 0000000..0a8f1b9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_b.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/no_interface_instantiation_b.vv:6:5: error: expected 1 arguments, but got 0
+    4 |
+    5 | fn main() {
+    6 |     my_fn()
+      |     ~~~~~~~
+    7 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_b.vv b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_b.vv
new file mode 100644
index 0000000..4c73538
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_b.vv
@@ -0,0 +1,7 @@
+interface Speaker {}
+
+fn my_fn(s Speaker) {}
+
+fn main() {
+    my_fn()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_c.out b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_c.out
new file mode 100644
index 0000000..11f0568
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_c.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/no_interface_instantiation_c.vv:9:9: error: cannot instantiate interface `Speaker`
+    7 | fn main() {
+    8 |     my_fn(
+    9 |         speak: 1
+      |         ~~~~~~~~
+   10 |     )
+   11 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_c.vv b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_c.vv
new file mode 100644
index 0000000..0eb6eec
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_interface_instantiation_c.vv
@@ -0,0 +1,11 @@
+interface Speaker {
+    speak()
+}
+
+fn my_fn(s Speaker) {}
+
+fn main() {
+    my_fn(
+        speak: 1
+    )
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_interface_str.out b/v_windows/v/old/vlib/v/checker/tests/no_interface_str.out
new file mode 100644
index 0000000..37b33f2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_interface_str.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/no_interface_str.vv:18:12: error: interface `Animal` does not have a .str() method. Use typeof() instead
+   16 | fn moin() {
+   17 |     a := get_animal()
+   18 |     println(a.str())
+      |               ~~~~~
+   19 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_interface_str.vv b/v_windows/v/old/vlib/v/checker/tests/no_interface_str.vv
new file mode 100644
index 0000000..b0da84a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_interface_str.vv
@@ -0,0 +1,19 @@
+interface Animal {
+	speak()
+}
+
+struct Cow {
+}
+
+fn (c Cow)speak() {
+	println('moo')
+}
+
+fn get_animal() Animal {
+	return Cow{}
+}
+
+fn moin() {
+	a := get_animal()
+	println(a.str())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_main_mod.out b/v_windows/v/old/vlib/v/checker/tests/no_main_mod.out
new file mode 100644
index 0000000..549575d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_main_mod.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/no_main_mod.vv:1:1: error: project must include a `main` module or be a shared library (compile with `v -shared`)
+    1 | module a
+      | ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_main_mod.vv b/v_windows/v/old/vlib/v/checker/tests/no_main_mod.vv
new file mode 100644
index 0000000..a32281d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_main_mod.vv
@@ -0,0 +1 @@
+module a
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_main_println_err.out b/v_windows/v/old/vlib/v/checker/tests/no_main_println_err.out
new file mode 100644
index 0000000..5b0d71e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_main_println_err.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/no_main_println_err.vv:1:5: error: expected 1 arguments, but got 0
+    1 |     println()
+      |     ~~~~~~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_main_println_err.vv b/v_windows/v/old/vlib/v/checker/tests/no_main_println_err.vv
new file mode 100644
index 0000000..2ac13fb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_main_println_err.vv
@@ -0,0 +1 @@
+    println()
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_method_on_interface_propagation.out b/v_windows/v/old/vlib/v/checker/tests/no_method_on_interface_propagation.out
new file mode 100644
index 0000000..b55e1d4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_method_on_interface_propagation.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/no_method_on_interface_propagation.vv:18:5: error: unknown method or field: `Cat.foo`
+   16 |     a := new_animal('persian')
+   17 |     if a is Cat {
+   18 |         a.foo()
+      |           ~~~~~
+   19 |     }
+   20 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_method_on_interface_propagation.vv b/v_windows/v/old/vlib/v/checker/tests/no_method_on_interface_propagation.vv
new file mode 100644
index 0000000..a9673df
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_method_on_interface_propagation.vv
@@ -0,0 +1,20 @@
+struct Cat {
+	breed string
+}
+
+interface Animal {
+	breed string
+}
+
+fn (a Animal) foo() {}
+
+fn new_animal(breed string) Animal {
+	return &Cat{breed}
+}
+
+fn test_methods_on_interfaces_dont_exist_on_implementers() {
+	a := new_animal('persian')
+	if a is Cat {
+		a.foo()
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_pub_in_main.out b/v_windows/v/old/vlib/v/checker/tests/no_pub_in_main.out
new file mode 100644
index 0000000..e1da080
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_pub_in_main.out
@@ -0,0 +1,49 @@
+vlib/v/checker/tests/no_pub_in_main.vv:3:1: error: type alias `Integer` in module main cannot be declared public
+    1 | module main
+    2 |
+    3 | pub type Integer = int
+      | ~~~~~~~~~~~~~~~~
+    4 |
+    5 | pub type Float = f32 | f64
+vlib/v/checker/tests/no_pub_in_main.vv:5:1: error: sum type `Float` in module main cannot be declared public
+    3 | pub type Integer = int
+    4 |
+    5 | pub type Float = f32 | f64
+      | ~~~~~~~~~~~~~~
+    6 |
+    7 | // Buggy ATM
+vlib/v/checker/tests/no_pub_in_main.vv:10:1: error: enum `Color` in module main cannot be declared public
+    8 | // pub type Fn = fn () int
+    9 |
+   10 | pub enum Color {
+      | ~~~~~~~~~~~~~~
+   11 |     red
+   12 |     green
+vlib/v/checker/tests/no_pub_in_main.vv:16:1: error: const in module main cannot be declared public
+   14 | }
+   15 |
+   16 | pub const (
+      | ~~~~~~~~~
+   17 |     w = 'world'
+   18 | )
+vlib/v/checker/tests/no_pub_in_main.vv:20:1: error: function `my_fn` in module main cannot be declared public
+   18 | )
+   19 |
+   20 | pub fn my_fn() int {
+      | ~~~~~~~~~~~~~~~~~~
+   21 |     return 1
+   22 | }
+vlib/v/checker/tests/no_pub_in_main.vv:24:1: error: function `main` cannot be declared public
+   22 | }
+   23 |
+   24 | pub fn main() {
+      | ~~~~~~~~~~~~~
+   25 |     println('main')
+   26 | }
+vlib/v/checker/tests/no_pub_in_main.vv:28:1: error: struct `MyStruct` in module main cannot be declared public
+   26 | }
+   27 |
+   28 | pub struct MyStruct {
+      | ~~~~~~~~~~~~~~~~~~~
+   29 |     field int
+   30 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_warning_for_in_mut_var_unused.out b/v_windows/v/old/vlib/v/checker/tests/no_warning_for_in_mut_var_unused.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_warning_for_in_mut_var_unused.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/no_warning_for_in_mut_var_unused.vv b/v_windows/v/old/vlib/v/checker/tests/no_warning_for_in_mut_var_unused.vv
new file mode 100644
index 0000000..3b66ce2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/no_warning_for_in_mut_var_unused.vv
@@ -0,0 +1,7 @@
+fn main() {
+	mut arr := [1, 2, 3]
+	for mut v in arr {
+		v = 2
+	}
+	println(arr)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/non_lvalue_as_voidptr.out b/v_windows/v/old/vlib/v/checker/tests/non_lvalue_as_voidptr.out
new file mode 100644
index 0000000..a885eb7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/non_lvalue_as_voidptr.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/non_lvalue_as_voidptr.vv:5:13: error: expression cannot be passed as `voidptr`
+    3 | }
+    4 | 
+    5 | println(add(5, 10))
+      |             ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/non_lvalue_as_voidptr.vv b/v_windows/v/old/vlib/v/checker/tests/non_lvalue_as_voidptr.vv
new file mode 100644
index 0000000..55de9f3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/non_lvalue_as_voidptr.vv
@@ -0,0 +1,5 @@
+fn add(a voidptr, b voidptr) int {
+	return int(a) + int(b)
+}
+
+println(add(5, 10))
diff --git a/v_windows/v/old/vlib/v/checker/tests/non_matching_functional_args.out b/v_windows/v/old/vlib/v/checker/tests/non_matching_functional_args.out
new file mode 100644
index 0000000..7d155d0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/non_matching_functional_args.out
@@ -0,0 +1,16 @@
+vlib/v/checker/tests/non_matching_functional_args.vv:27:6: error: cannot use `fn (mut Table)` as `fn (Table)` in argument 1 to `sum`
+   25 |
+   26 | fn main() {
+   27 |     sum(fn (mut t Table) {
+      |         ~~~~~~~~~~~~~~~~~~
+   28 |         t.rename()
+   29 |         println(t.name)
+Details: `main.MyFn`'s expected fn argument: `zzzz` is NOT a pointer, but the passed fn argument: `t` is a pointer
+vlib/v/checker/tests/non_matching_functional_args.vv:31:6: error: cannot use `fn (mut Table)` as `fn (Table)` in argument 1 to `sum`
+   29 |         println(t.name)
+   30 |     })
+   31 |     sum(xxx)
+      |         ~~~
+   32 |     sum(yyy)
+   33 | }
+Details: `main.MyFn`'s expected fn argument: `zzzz` is NOT a pointer, but the passed fn argument: `mytable` is a pointer
diff --git a/v_windows/v/old/vlib/v/checker/tests/non_matching_functional_args.vv b/v_windows/v/old/vlib/v/checker/tests/non_matching_functional_args.vv
new file mode 100644
index 0000000..a0e90ff
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/non_matching_functional_args.vv
@@ -0,0 +1,33 @@
+struct Table {
+pub mut:
+	name string
+}
+
+type MyFn = fn (zzzz Table)
+
+fn (mut t Table) rename() {
+	t.name = 'abc'
+}
+
+fn yyy(t Table) {
+	println(t.name)
+}
+
+fn xxx(mut mytable Table) {
+	mytable.rename()
+	println(mytable.name)
+}
+
+fn sum(myfn MyFn) {
+	mut t := Table{}
+	myfn(t)
+}
+
+fn main() {
+	sum(fn (mut t Table) {
+		t.rename()
+		println(t.name)
+	})
+	sum(xxx)
+	sum(yyy)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/none_type_cast_err.out b/v_windows/v/old/vlib/v/checker/tests/none_type_cast_err.out
new file mode 100644
index 0000000..0d0ba86
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/none_type_cast_err.out
@@ -0,0 +1,75 @@
+vlib/v/checker/tests/none_type_cast_err.vv:2:7: error: cannot cast `none` to `string`
+    1 | fn main() {
+    2 |     _ := string(none)
+      |          ~~~~~~~~~~~~
+    3 |     _ := int(none)
+    4 |     _ := i8(none)
+vlib/v/checker/tests/none_type_cast_err.vv:3:7: error: cannot cast `none` to `int`
+    1 | fn main() {
+    2 |     _ := string(none)
+    3 |     _ := int(none)
+      |          ~~~~~~~~~
+    4 |     _ := i8(none)
+    5 |     _ := i16(none)
+vlib/v/checker/tests/none_type_cast_err.vv:4:7: error: cannot cast `none` to `i8`
+    2 |     _ := string(none)
+    3 |     _ := int(none)
+    4 |     _ := i8(none)
+      |          ~~~~~~~~
+    5 |     _ := i16(none)
+    6 |     _ := i64(none)
+vlib/v/checker/tests/none_type_cast_err.vv:5:7: error: cannot cast `none` to `i16`
+    3 |     _ := int(none)
+    4 |     _ := i8(none)
+    5 |     _ := i16(none)
+      |          ~~~~~~~~~
+    6 |     _ := i64(none)
+    7 |     _ := u16(none)
+vlib/v/checker/tests/none_type_cast_err.vv:6:7: error: cannot cast `none` to `i64`
+    4 |     _ := i8(none)
+    5 |     _ := i16(none)
+    6 |     _ := i64(none)
+      |          ~~~~~~~~~
+    7 |     _ := u16(none)
+    8 |     _ := u32(none)
+vlib/v/checker/tests/none_type_cast_err.vv:7:7: error: cannot cast `none` to `u16`
+    5 |     _ := i16(none)
+    6 |     _ := i64(none)
+    7 |     _ := u16(none)
+      |          ~~~~~~~~~
+    8 |     _ := u32(none)
+    9 |     _ := u64(none)
+vlib/v/checker/tests/none_type_cast_err.vv:8:7: error: cannot cast `none` to `u32`
+    6 |     _ := i64(none)
+    7 |     _ := u16(none)
+    8 |     _ := u32(none)
+      |          ~~~~~~~~~
+    9 |     _ := u64(none)
+   10 |     _ := rune(none)
+vlib/v/checker/tests/none_type_cast_err.vv:9:7: error: cannot cast `none` to `u64`
+    7 |     _ := u16(none)
+    8 |     _ := u32(none)
+    9 |     _ := u64(none)
+      |          ~~~~~~~~~
+   10 |     _ := rune(none)
+   11 |     _ := f32(none)
+vlib/v/checker/tests/none_type_cast_err.vv:10:7: error: cannot cast `none` to `rune`
+    8 |     _ := u32(none)
+    9 |     _ := u64(none)
+   10 |     _ := rune(none)
+      |          ~~~~~~~~~~
+   11 |     _ := f32(none)
+   12 |     _ := f64(none)
+vlib/v/checker/tests/none_type_cast_err.vv:11:7: error: cannot cast `none` to `f32`
+    9 |     _ := u64(none)
+   10 |     _ := rune(none)
+   11 |     _ := f32(none)
+      |          ~~~~~~~~~
+   12 |     _ := f64(none)
+   13 | }
+vlib/v/checker/tests/none_type_cast_err.vv:12:7: error: cannot cast `none` to `f64`
+   10 |     _ := rune(none)
+   11 |     _ := f32(none)
+   12 |     _ := f64(none)
+      |          ~~~~~~~~~
+   13 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/none_type_cast_err.vv b/v_windows/v/old/vlib/v/checker/tests/none_type_cast_err.vv
new file mode 100644
index 0000000..953b369
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/none_type_cast_err.vv
@@ -0,0 +1,13 @@
+fn main() {
+	_ := string(none)
+	_ := int(none)
+	_ := i8(none)
+	_ := i16(none)
+	_ := i64(none)
+	_ := u16(none)
+	_ := u32(none)
+	_ := u64(none)
+	_ := rune(none)
+	_ := f32(none)
+	_ := f64(none)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/noreturn_with_non_empty_loop_at_end.out b/v_windows/v/old/vlib/v/checker/tests/noreturn_with_non_empty_loop_at_end.out
new file mode 100644
index 0000000..02fbccc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/noreturn_with_non_empty_loop_at_end.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/noreturn_with_non_empty_loop_at_end.vv:4:6: error: [noreturn] functions should end with a call to another [noreturn] function, or with an infinite `for {}` loop
+    2 | fn another() {
+    3 |     eprintln(@FN)
+    4 |     for {
+      |         ^
+    5 |         break
+    6 |     }
+vlib/v/checker/tests/noreturn_with_non_empty_loop_at_end.vv:18:2: error: unreachable code after a [noreturn] call
+   16 |     eprintln('start')
+   17 |     abc()
+   18 |     eprintln('done')
+      |     ~~~~~~~~~~~~~~~~
+   19 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/noreturn_with_non_empty_loop_at_end.vv b/v_windows/v/old/vlib/v/checker/tests/noreturn_with_non_empty_loop_at_end.vv
new file mode 100644
index 0000000..84f413c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/noreturn_with_non_empty_loop_at_end.vv
@@ -0,0 +1,19 @@
+[noreturn]
+fn another() {
+	eprintln(@FN)
+	for {
+		break
+	}
+}
+
+[noreturn]
+fn abc() {
+	eprintln(@FN)
+	another()
+}
+
+fn main() {
+	eprintln('start')
+	abc()
+	eprintln('done')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/noreturn_with_return.out b/v_windows/v/old/vlib/v/checker/tests/noreturn_with_return.out
new file mode 100644
index 0000000..d8c3279
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/noreturn_with_return.out
@@ -0,0 +1,19 @@
+vlib/v/checker/tests/noreturn_with_return.vv:2:1: error: [noreturn] functions cannot use return statements
+    1 | [noreturn]
+    2 | fn another() {
+      | ~~~~~~~~~~~~
+    3 |     eprintln(@FN)
+    4 |     // for{}
+vlib/v/checker/tests/noreturn_with_return.vv:6:2: error: [noreturn] functions should end with a call to another [noreturn] function, or with an infinite `for {}` loop
+    4 |     // for{}
+    5 |     // exit(0)
+    6 |     return
+      |     ~~~~~~
+    7 | }
+    8 |
+vlib/v/checker/tests/noreturn_with_return.vv:18:2: error: unreachable code after a [noreturn] call
+   16 |     eprintln('start')
+   17 |     abc()
+   18 |     eprintln('done')
+      |     ~~~~~~~~~~~~~~~~
+   19 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/noreturn_with_return.vv b/v_windows/v/old/vlib/v/checker/tests/noreturn_with_return.vv
new file mode 100644
index 0000000..c5fdaa7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/noreturn_with_return.vv
@@ -0,0 +1,19 @@
+[noreturn]
+fn another() {
+	eprintln(@FN)
+	// for{}
+	// exit(0)
+	return
+}
+
+[noreturn]
+fn abc() {
+	eprintln(@FN)
+	another()
+}
+
+fn main() {
+	eprintln('start')
+	abc()
+	eprintln('done')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/noreturn_without_loop_or_another_noreturn_at_end.out b/v_windows/v/old/vlib/v/checker/tests/noreturn_without_loop_or_another_noreturn_at_end.out
new file mode 100644
index 0000000..6215215
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/noreturn_without_loop_or_another_noreturn_at_end.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/noreturn_without_loop_or_another_noreturn_at_end.vv:3:2: error: [noreturn] functions should end with a call to another [noreturn] function, or with an infinite `for {}` loop
+    1 | [noreturn]
+    2 | fn another() {
+    3 |     eprintln(@FN)
+      |     ~~~~~~~~~~~~~
+    4 | }
+    5 |
+vlib/v/checker/tests/noreturn_without_loop_or_another_noreturn_at_end.vv:15:2: error: unreachable code after a [noreturn] call
+   13 |     eprintln('start')
+   14 |     abc()
+   15 |     eprintln('done')
+      |     ~~~~~~~~~~~~~~~~
+   16 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/noreturn_without_loop_or_another_noreturn_at_end.vv b/v_windows/v/old/vlib/v/checker/tests/noreturn_without_loop_or_another_noreturn_at_end.vv
new file mode 100644
index 0000000..d764d7d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/noreturn_without_loop_or_another_noreturn_at_end.vv
@@ -0,0 +1,16 @@
+[noreturn]
+fn another() {
+	eprintln(@FN)
+}
+
+[noreturn]
+fn abc() {
+	eprintln(@FN)
+	another()
+}
+
+fn main() {
+	eprintln('start')
+	abc()
+	eprintln('done')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/oct_lit_without_digit_err.out b/v_windows/v/old/vlib/v/checker/tests/oct_lit_without_digit_err.out
new file mode 100644
index 0000000..29eac2d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/oct_lit_without_digit_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/oct_lit_without_digit_err.vv:2:14: error: number part of this octal is not provided
+    1 | fn main() {
+    2 |     println(0o)
+      |              ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/oct_lit_without_digit_err.vv b/v_windows/v/old/vlib/v/checker/tests/oct_lit_without_digit_err.vv
new file mode 100644
index 0000000..195a010
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/oct_lit_without_digit_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(0o)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/oct_lit_wrong_digit_err.out b/v_windows/v/old/vlib/v/checker/tests/oct_lit_wrong_digit_err.out
new file mode 100644
index 0000000..0dbccf9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/oct_lit_wrong_digit_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/oct_lit_wrong_digit_err.vv:2:18: error: this octal number has unsuitable digit `8`
+    1 | fn main() {
+    2 |     println(0o1118)
+      |                  ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/oct_lit_wrong_digit_err.vv b/v_windows/v/old/vlib/v/checker/tests/oct_lit_wrong_digit_err.vv
new file mode 100644
index 0000000..235e1a9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/oct_lit_wrong_digit_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(0o1118)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_fn_err.out b/v_windows/v/old/vlib/v/checker/tests/optional_fn_err.out
new file mode 100644
index 0000000..3e47b49
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_fn_err.out
@@ -0,0 +1,168 @@
+vlib/v/checker/tests/optional_fn_err.vv:13:16: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   11 | 
+   12 | const (
+   13 |     const_value = bar(0)
+      |                   ~~~~~~
+   14 | )
+   15 |
+vlib/v/checker/tests/optional_fn_err.vv:19:14: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   17 |     f fn (int)
+   18 | mut:
+   19 |     value int = bar(0)
+      |                 ~~~~~~
+   20 |     opt   ?int = bar(0)
+   21 | }
+vlib/v/checker/tests/optional_fn_err.vv:33:2: error: foo() returns an option, so it should have either an `or {}` block, or `?` at the end
+   31 | fn main() {
+   32 |     // call fn
+   33 |     foo()
+      |     ~~~~~
+   34 |     _ := bar(0)
+   35 |     println(twice(bar(0)))
+vlib/v/checker/tests/optional_fn_err.vv:34:7: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   32 |     // call fn
+   33 |     foo()
+   34 |     _ := bar(0)
+      |          ~~~~~~
+   35 |     println(twice(bar(0)))
+   36 |
+vlib/v/checker/tests/optional_fn_err.vv:35:16: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   33 |     foo()
+   34 |     _ := bar(0)
+   35 |     println(twice(bar(0)))
+      |                   ~~~~~~
+   36 | 
+   37 |     // anon fn
+vlib/v/checker/tests/optional_fn_err.vv:38:16: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   36 | 
+   37 |     // anon fn
+   38 |     fn (_ int) {}(bar(0))
+      |                   ~~~~~~
+   39 | 
+   40 |     // assert
+vlib/v/checker/tests/optional_fn_err.vv:41:9: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   39 | 
+   40 |     // assert
+   41 |     assert bar(true)
+      |            ~~~~~~~~~
+   42 | 
+   43 |     // struct
+vlib/v/checker/tests/optional_fn_err.vv:46:10: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   44 |     mut v := Data{
+   45 |         f: fn (_ int) {},
+   46 |         value: bar(0),
+      |                ~~~~~~
+   47 |         opt: bar(0),
+   48 |     }
+vlib/v/checker/tests/optional_fn_err.vv:49:8: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   47 |         opt: bar(0),
+   48 |     }
+   49 |     v.add(bar(0)) // call method
+      |           ~~~~~~
+   50 |     v.f(bar(0)) // call fn field
+   51 |
+vlib/v/checker/tests/optional_fn_err.vv:50:6: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   48 |     }
+   49 |     v.add(bar(0)) // call method
+   50 |     v.f(bar(0)) // call fn field
+      |         ~~~~~~
+   51 | 
+   52 |     // array
+vlib/v/checker/tests/optional_fn_err.vv:54:9: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   52 |     // array
+   53 |     mut arr := [1, 2]
+   54 |     arr << bar(0)
+      |            ~~~~~~
+   55 |     // init
+   56 |     _ := [bar(0)]
+vlib/v/checker/tests/optional_fn_err.vv:56:8: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   54 |     arr << bar(0)
+   55 |     // init
+   56 |     _ := [bar(0)]
+      |           ~~~~~~
+   57 |     _ := []int{init: bar(0)}
+   58 |     _ := [bar(0)]!
+vlib/v/checker/tests/optional_fn_err.vv:57:19: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   55 |     // init
+   56 |     _ := [bar(0)]
+   57 |     _ := []int{init: bar(0)}
+      |                      ~~~~~~
+   58 |     _ := [bar(0)]!
+   59 |     _ := [1]int{init: bar(0)}
+vlib/v/checker/tests/optional_fn_err.vv:58:8: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   56 |     _ := [bar(0)]
+   57 |     _ := []int{init: bar(0)}
+   58 |     _ := [bar(0)]!
+      |           ~~~~~~
+   59 |     _ := [1]int{init: bar(0)}
+   60 |     // index
+vlib/v/checker/tests/optional_fn_err.vv:61:13: error: cannot use optional as index (array type `[]int`)
+   59 |     _ := [1]int{init: bar(0)}
+   60 |     // index
+   61 |     println(arr[bar(0)])
+      |                ~~~~~~~~
+   62 |     // array builtin methods
+   63 |     arr.insert(0, bar(0))
+vlib/v/checker/tests/optional_fn_err.vv:63:16: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   61 |     println(arr[bar(0)])
+   62 |     // array builtin methods
+   63 |     arr.insert(0, bar(0))
+      |                   ~~~~~~
+   64 |     arr.prepend(bar(0))
+   65 |     arr.contains(bar(0))
+vlib/v/checker/tests/optional_fn_err.vv:64:14: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   62 |     // array builtin methods
+   63 |     arr.insert(0, bar(0))
+   64 |     arr.prepend(bar(0))
+      |                 ~~~~~~
+   65 |     arr.contains(bar(0))
+   66 |     arr.index(bar(0))
+vlib/v/checker/tests/optional_fn_err.vv:65:15: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   63 |     arr.insert(0, bar(0))
+   64 |     arr.prepend(bar(0))
+   65 |     arr.contains(bar(0))
+      |                  ~~~~~~
+   66 |     arr.index(bar(0))
+   67 |     println(arr.map(bar(0)))
+vlib/v/checker/tests/optional_fn_err.vv:66:12: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   64 |     arr.prepend(bar(0))
+   65 |     arr.contains(bar(0))
+   66 |     arr.index(bar(0))
+      |               ~~~~~~
+   67 |     println(arr.map(bar(0)))
+   68 |     println(arr.filter(bar(true)))
+vlib/v/checker/tests/optional_fn_err.vv:67:18: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   65 |     arr.contains(bar(0))
+   66 |     arr.index(bar(0))
+   67 |     println(arr.map(bar(0)))
+      |                     ~~~~~~
+   68 |     println(arr.filter(bar(true)))
+   69 |     println(arr.any(bar(true)))
+vlib/v/checker/tests/optional_fn_err.vv:68:21: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   66 |     arr.index(bar(0))
+   67 |     println(arr.map(bar(0)))
+   68 |     println(arr.filter(bar(true)))
+      |                        ~~~~~~~~~
+   69 |     println(arr.any(bar(true)))
+   70 |     println(arr.all(bar(true)))
+vlib/v/checker/tests/optional_fn_err.vv:69:18: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   67 |     println(arr.map(bar(0)))
+   68 |     println(arr.filter(bar(true)))
+   69 |     println(arr.any(bar(true)))
+      |                     ~~~~~~~~~
+   70 |     println(arr.all(bar(true)))
+   71 |
+vlib/v/checker/tests/optional_fn_err.vv:70:18: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   68 |     println(arr.filter(bar(true)))
+   69 |     println(arr.any(bar(true)))
+   70 |     println(arr.all(bar(true)))
+      |                     ~~~~~~~~~
+   71 | 
+   72 |     match bar(0) {
+vlib/v/checker/tests/optional_fn_err.vv:72:8: error: bar() returns an option, so it should have either an `or {}` block, or `?` at the end
+   70 |     println(arr.all(bar(true)))
+   71 | 
+   72 |     match bar(0) {
+      |           ~~~~~~
+   73 |         0 { }
+   74 |         else { }
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_fn_err.vv b/v_windows/v/old/vlib/v/checker/tests/optional_fn_err.vv
new file mode 100644
index 0000000..b3d82d1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_fn_err.vv
@@ -0,0 +1,76 @@
+
+// use optional without ? or an or block in places where it is not allowed
+
+fn foo() ? {
+	println('foo is called')
+}
+
+fn bar<T>(v T) ?T {
+	return none
+}
+
+const (
+	const_value = bar(0)
+)
+
+struct Data {
+	f fn (int)
+mut:
+	value int = bar(0)
+	opt   ?int = bar(0)
+}
+
+fn (mut v Data) add(n int) {
+	v.value += n
+}
+
+fn twice(n int) int {
+	return n * 2
+}
+
+fn main() {
+	// call fn
+	foo()
+	_ := bar(0)
+	println(twice(bar(0)))
+
+	// anon fn
+	fn (_ int) {}(bar(0))
+
+	// assert
+	assert bar(true)
+
+	// struct
+	mut v := Data{
+		f: fn (_ int) {},
+		value: bar(0),
+		opt: bar(0),
+	}
+	v.add(bar(0)) // call method
+	v.f(bar(0)) // call fn field
+
+	// array
+	mut arr := [1, 2]
+	arr << bar(0)
+	// init
+	_ := [bar(0)]
+	_ := []int{init: bar(0)}
+	_ := [bar(0)]!
+	_ := [1]int{init: bar(0)}
+	// index
+	println(arr[bar(0)])
+	// array builtin methods
+	arr.insert(0, bar(0))
+	arr.prepend(bar(0))
+	arr.contains(bar(0))
+	arr.index(bar(0))
+	println(arr.map(bar(0)))
+	println(arr.filter(bar(true)))
+	println(arr.any(bar(true)))
+	println(arr.all(bar(true)))
+
+	match bar(0) {
+		0 { }
+		else { }
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_in_println_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/optional_in_println_mismatch.out
new file mode 100644
index 0000000..8f13586
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_in_println_mismatch.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/optional_in_println_mismatch.vv:6:23: error: wrong return type `string` in the `or {}` block, expected `int`
+    4 |
+    5 | fn main() {
+    6 |     println(funcy() or { '' })
+      |                          ~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_in_println_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/optional_in_println_mismatch.vv
new file mode 100644
index 0000000..fd3d067
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_in_println_mismatch.vv
@@ -0,0 +1,7 @@
+fn funcy() ?int {
+	return none
+}
+
+fn main() {
+	println(funcy() or { '' })
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_interface_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/optional_interface_mismatch.out
new file mode 100644
index 0000000..64fe585
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_interface_mismatch.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/optional_interface_mismatch.vv:11:9: error: mismatched types `?MObject` and `string`
+    9 |
+   10 | fn give_string(line string) ?MObject {
+   11 |     return if true { 'string' } else { 'string' }
+      |            ~~
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_interface_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/optional_interface_mismatch.vv
new file mode 100644
index 0000000..1138fa3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_interface_mismatch.vv
@@ -0,0 +1,12 @@
+fn main() {
+	le_string := give_string('string') or { return }
+	le_string.unimplemented()
+}
+
+interface MObject {
+	unimplemented() string
+}
+
+fn give_string(line string) ?MObject {
+	return if true { 'string' } else { 'string' }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_or_block_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_mismatch.out
new file mode 100644
index 0000000..d48fd8f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_mismatch.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/optional_or_block_mismatch.vv:10:18: error: wrong return type `Bar` in the `or {}` block, expected `&Bar`
+    8 | 
+    9 | fn main() {
+   10 |     x := foo() or { Bar{} }
+      |                     ~~~~~
+   11 |     println(x)
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_or_block_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_mismatch.vv
new file mode 100644
index 0000000..849a7aa
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_mismatch.vv
@@ -0,0 +1,12 @@
+module main
+
+struct Bar {}
+
+fn foo() ?&Bar {
+	return none
+}
+
+fn main() {
+	x := foo() or { Bar{} }
+	println(x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_or_block_none_err.out b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_none_err.out
new file mode 100644
index 0000000..ed608c3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_none_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/optional_or_block_none_err.vv:18:3: error: wrong return type `none` in the `or {}` block, expected `Animal`
+   16 | fn main() {
+   17 |     mut dog := new_animal(9) or {
+   18 |         none
+      |         ~~~~
+   19 |     }
+   20 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_or_block_none_err.vv b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_none_err.vv
new file mode 100644
index 0000000..c1970a3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_none_err.vv
@@ -0,0 +1,22 @@
+module main
+
+struct Animal {
+	mut:
+		height byte
+}
+
+fn new_animal(height byte) ?Animal {
+	if height < 10 {
+		return error('Too small to be an animal!')
+	}
+
+	return Animal{ height: height }
+}
+
+fn main() {
+	mut dog := new_animal(9) or {
+		none
+	}
+
+	println(dog)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_or_block_returns_value_of_incompatible_type.out b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_returns_value_of_incompatible_type.out
new file mode 100644
index 0000000..0cd1b38
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_returns_value_of_incompatible_type.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/optional_or_block_returns_value_of_incompatible_type.vv:13:3: error: the default expression type in the `or` block should be `string`, instead you gave a value of type `int literal`
+   11 |         // must be of the same type of the return
+   12 |         // type of the `test_optional` function
+   13 |         123
+      |         ~~~
+   14 |         // 'I break things'
+   15 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_or_block_returns_value_of_incompatible_type.vv b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_returns_value_of_incompatible_type.vv
new file mode 100644
index 0000000..9935bb7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_or_block_returns_value_of_incompatible_type.vv
@@ -0,0 +1,16 @@
+fn test_optional(fail bool) ?string {
+	if fail {
+		return error('false')
+	}
+	return 'fff'
+}
+
+fn main() {
+	// a := test_optional(false) or { println(err) }
+	test_optional(true) or {
+		// must be of the same type of the return
+		// type of the `test_optional` function
+		123
+		// 'I break things'
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_propagate_nested.out b/v_windows/v/old/vlib/v/checker/tests/optional_propagate_nested.out
new file mode 100644
index 0000000..f113a89
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_propagate_nested.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/optional_propagate_nested.vv:10:19: error: to propagate the optional call, `xx_prop` must return an optional
+    8 | 
+    9 | fn xx_prop() string {
+   10 |     s := ret(raise() ?)
+      |                      ^
+   11 |     return s
+   12 | }
+vlib/v/checker/tests/optional_propagate_nested.vv:28:22: error: to propagate the optional call, `aa_propagate` must return an optional
+   26 | 
+   27 | fn (mut s St) aa_propagate() {
+   28 |     f := retf(s.raise() ?)
+      |                         ^
+   29 |     s.z = 7.5
+   30 |     println(f)
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_propagate_nested.vv b/v_windows/v/old/vlib/v/checker/tests/optional_propagate_nested.vv
new file mode 100644
index 0000000..d00ef53
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_propagate_nested.vv
@@ -0,0 +1,31 @@
+fn ret(s string) string {
+	return s
+}
+
+fn raise() ?string {
+	return none
+}
+
+fn xx_prop() string {
+	s := ret(raise() ?)
+	return s
+}
+
+struct St {
+mut:
+	z f64
+}
+
+fn (mut s St) raise() ?f64 {
+	return error('some error')
+}
+
+fn retf(f f64) f64 {
+	return f
+}
+
+fn (mut s St) aa_propagate() {
+	f := retf(s.raise() ?)
+	s.z = 7.5
+	println(f)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_type_call_err.out b/v_windows/v/old/vlib/v/checker/tests/optional_type_call_err.out
new file mode 100644
index 0000000..6550765
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_type_call_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/optional_type_call_err.vv:4:5: error: optional type cannot be called directly
+    2 |
+    3 | fn main() {
+    4 |     os.ls('.').filter(it.ends_with('.v')) or { return }
+      |        ~~~~~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/optional_type_call_err.vv b/v_windows/v/old/vlib/v/checker/tests/optional_type_call_err.vv
new file mode 100644
index 0000000..1b0cfa0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/optional_type_call_err.vv
@@ -0,0 +1,5 @@
+import os
+
+fn main() {
+	os.ls('.').filter(it.ends_with('.v')) or { return }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/or_err.out b/v_windows/v/old/vlib/v/checker/tests/or_err.out
new file mode 100644
index 0000000..5aaf5f2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/or_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/or_err.vv:4:10: error: last statement in the `or {}` block should be an expression of type `&int` or exit parent scope
+    2 |     return none
+    3 | }
+    4 | a := f() or {
+      |          ~~~~
+    5 |     {}
+    6 | }
+vlib/v/checker/tests/or_err.vv:11:2: error: wrong return type `rune` in the `or {}` block, expected `&int`
+    9 | }
+   10 | _ = f() or {
+   11 |     `.`
+      |     ~~~
+   12 | }
+   13 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/or_err.vv b/v_windows/v/old/vlib/v/checker/tests/or_err.vv
new file mode 100644
index 0000000..035b87e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/or_err.vv
@@ -0,0 +1,13 @@
+fn f() ?&int {
+	return none
+}
+a := f() or {
+	{}
+}
+_ = f() or {
+	a
+}
+_ = f() or {
+	`.`
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/or_expr_types_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/or_expr_types_mismatch.out
new file mode 100644
index 0000000..c84faa5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/or_expr_types_mismatch.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/or_expr_types_mismatch.vv:3:19: error: wrong return type `none` in the `or {}` block, expected `string`
+    1 | fn get_map() ?string {
+    2 |     m := map{1: 'a', 2: 'b'}
+    3 |     return m[1] or { none }
+      |                      ~~~~
+    4 | }
+    5 |
+vlib/v/checker/tests/or_expr_types_mismatch.vv:8:19: error: wrong return type `none` in the `or {}` block, expected `int`
+    6 | fn get_array() ?int {
+    7 |     a := [1, 2, 3]
+    8 |     return a[4] or { none }
+      |                      ~~~~
+    9 | }
+   10 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/or_expr_types_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/or_expr_types_mismatch.vv
new file mode 100644
index 0000000..1b557c3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/or_expr_types_mismatch.vv
@@ -0,0 +1,17 @@
+fn get_map() ?string {
+	m := map{1: 'a', 2: 'b'}
+	return m[1] or { none }
+}
+
+fn get_array() ?int {
+	a := [1, 2, 3]
+	return a[4] or { none }
+}
+
+fn main() {
+	map_result := get_map() or { return }
+	println(map_result)
+
+	array_result := get_array() or { return }
+	println(array_result)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/orm_empty_struct.out b/v_windows/v/old/vlib/v/checker/tests/orm_empty_struct.out
new file mode 100644
index 0000000..26e5131
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/orm_empty_struct.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/orm_empty_struct.vv:9:15: error: V orm: select: empty fields in `Person`
+    7 |     db := sqlite.connect(':memory:')?
+    8 |     _ := sql db {
+    9 |         select from Person
+      |                     ~~~~~~
+   10 |     }
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/orm_empty_struct.vv b/v_windows/v/old/vlib/v/checker/tests/orm_empty_struct.vv
new file mode 100644
index 0000000..ba7b4e7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/orm_empty_struct.vv
@@ -0,0 +1,11 @@
+import sqlite
+
+struct Person {
+}
+
+fn main() {
+	db := sqlite.connect(':memory:')?
+	_ := sql db {
+		select from Person
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/os_prefix.out b/v_windows/v/old/vlib/v/checker/tests/os_prefix.out
new file mode 100644
index 0000000..4b87a6f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/os_prefix.out
@@ -0,0 +1,18 @@
+vlib/v/checker/tests/os_prefix.vv:1:8: warning: module 'os' is imported but never used
+    1 | import os
+      |        ~~
+    2 |
+    3 | fn main() {
+vlib/v/checker/tests/os_prefix.vv:5:12: error: unknown function: execute
+    3 | fn main() {
+    4 |     cmd := "ls"
+    5 |     result := execute(cmd)
+      |               ~~~~~~~~~~~~
+    6 |     println(result)
+    7 | }
+vlib/v/checker/tests/os_prefix.vv:6:2: error: `println` can not print void expressions
+    4 |     cmd := "ls"
+    5 |     result := execute(cmd)
+    6 |     println(result)
+      |     ~~~~~~~~~~~~~~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/os_prefix.vv b/v_windows/v/old/vlib/v/checker/tests/os_prefix.vv
new file mode 100644
index 0000000..b9342d3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/os_prefix.vv
@@ -0,0 +1,7 @@
+import os
+
+fn main() {
+	cmd := "ls"
+	result := execute(cmd)
+	println(result)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/overflow_int_err.out b/v_windows/v/old/vlib/v/checker/tests/overflow_int_err.out
new file mode 100644
index 0000000..b26b097
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/overflow_int_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/overflow_int_err.vv:4:7: error: overflow in implicit type `int`, use explicit type casting instead
+    2 |     a := -2147483648
+    3 |     b := 2147483647
+    4 |     c := -2147483649
+      |          ~~~~~~~~~~~
+    5 |     d := 2147483648
+    6 |     println(a)
+vlib/v/checker/tests/overflow_int_err.vv:5:7: error: overflow in implicit type `int`, use explicit type casting instead
+    3 |     b := 2147483647
+    4 |     c := -2147483649
+    5 |     d := 2147483648
+      |          ~~~~~~~~~~
+    6 |     println(a)
+    7 |     println(b)
diff --git a/v_windows/v/old/vlib/v/checker/tests/overflow_int_err.vv b/v_windows/v/old/vlib/v/checker/tests/overflow_int_err.vv
new file mode 100644
index 0000000..0537ae3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/overflow_int_err.vv
@@ -0,0 +1,10 @@
+fn main() {
+	a := -2147483648
+	b := 2147483647
+	c := -2147483649
+	d := 2147483648
+	println(a)
+	println(b)
+	println(c)
+	println(d)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/overload_return_type.out b/v_windows/v/old/vlib/v/checker/tests/overload_return_type.out
new file mode 100644
index 0000000..547519c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/overload_return_type.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/overload_return_type.vv:14:11: error: cannot assign to `two`: expected `Point`, not `int`
+   12 |     mut one := Point {x:1, y:2}
+   13 |     mut two := Point {x:5, y:1}
+   14 |     two = one + two
+      |           ~~~~~~~~~
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/overload_return_type.vv b/v_windows/v/old/vlib/v/checker/tests/overload_return_type.vv
new file mode 100644
index 0000000..f9ae2f1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/overload_return_type.vv
@@ -0,0 +1,15 @@
+struct Point {
+    mut:
+        x int
+        y int
+}
+
+fn (a Point) +(b Point) int {
+    return a.x + b.x
+}
+
+fn main() {
+    mut one := Point {x:1, y:2}
+    mut two := Point {x:5, y:1}
+    two = one + two
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/oversized_int_lit.out b/v_windows/v/old/vlib/v/checker/tests/oversized_int_lit.out
new file mode 100644
index 0000000..30a9622
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/oversized_int_lit.out
@@ -0,0 +1,8 @@
+vlib/v/checker/tests/oversized_int_lit.vv:1:8: error: integer literal 18446744073709551616 overflows int
+    1 | assert 18446744073709551616 > 0
+      |        ~~~~~~~~~~~~~~~~~~~~
+    2 | assert -9223372036854775809 < 0
+vlib/v/checker/tests/oversized_int_lit.vv:2:8: error: integer literal -9223372036854775809 overflows int
+    1 | assert 18446744073709551616 > 0
+    2 | assert -9223372036854775809 < 0
+      |        ~~~~~~~~~~~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/oversized_int_lit.vv b/v_windows/v/old/vlib/v/checker/tests/oversized_int_lit.vv
new file mode 100644
index 0000000..d6e3a27
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/oversized_int_lit.vv
@@ -0,0 +1,2 @@
+assert 18446744073709551616 > 0
+assert -9223372036854775809 < 0
diff --git a/v_windows/v/old/vlib/v/checker/tests/pass_mut_lit.out b/v_windows/v/old/vlib/v/checker/tests/pass_mut_lit.out
new file mode 100644
index 0000000..09a0343
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/pass_mut_lit.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/pass_mut_lit.vv:10:12: error: cannot pass expression as `mut`
+    8 | }
+    9 | 
+   10 | modify(mut Box{}, 10)
+      |            ~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/pass_mut_lit.vv b/v_windows/v/old/vlib/v/checker/tests/pass_mut_lit.vv
new file mode 100644
index 0000000..7d358f9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/pass_mut_lit.vv
@@ -0,0 +1,10 @@
+struct Box {
+mut:
+	value int
+}
+
+fn modify(mut box Box, value int) {
+	box.value = value
+}
+
+modify(mut Box{}, 10)
diff --git a/v_windows/v/old/vlib/v/checker/tests/passing_expr_to_fn_expecting_voidptr.out b/v_windows/v/old/vlib/v/checker/tests/passing_expr_to_fn_expecting_voidptr.out
new file mode 100644
index 0000000..1acbdb5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/passing_expr_to_fn_expecting_voidptr.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/passing_expr_to_fn_expecting_voidptr.vv:3:31: error: expression cannot be passed as `voidptr`
+    1 | import strconv
+    2 | 
+    3 | strconv.v_printf('%02.02f\n', 1.1)
+      |                               ~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/passing_expr_to_fn_expecting_voidptr.vv b/v_windows/v/old/vlib/v/checker/tests/passing_expr_to_fn_expecting_voidptr.vv
new file mode 100644
index 0000000..1b3bc39
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/passing_expr_to_fn_expecting_voidptr.vv
@@ -0,0 +1,3 @@
+import strconv
+
+strconv.v_printf('%02.02f\n', 1.1)
diff --git a/v_windows/v/old/vlib/v/checker/tests/pointer_ops.out b/v_windows/v/old/vlib/v/checker/tests/pointer_ops.out
new file mode 100644
index 0000000..0221116
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/pointer_ops.out
@@ -0,0 +1,49 @@
+vlib/v/checker/tests/pointer_ops.vv:5:7: error: `+` cannot be used with `voidptr`
+    3 |     unsafe {
+    4 |         mut p := voidptr(0)
+    5 |         _ = p + 1
+      |             ^
+    6 |         p++
+    7 |         p += 3
+vlib/v/checker/tests/pointer_ops.vv:6:4: error: invalid operation: ++ (non-numeric type `voidptr`)
+    4 |         mut p := voidptr(0)
+    5 |         _ = p + 1
+    6 |         p++
+      |          ~~
+    7 |         p += 3
+    8 |         _ = p - 1
+vlib/v/checker/tests/pointer_ops.vv:7:3: error: operator `+=` not defined on left operand type `voidptr`
+    5 |         _ = p + 1
+    6 |         p++
+    7 |         p += 3
+      |         ^
+    8 |         _ = p - 1
+    9 |         p--
+vlib/v/checker/tests/pointer_ops.vv:8:7: error: `-` cannot be used with `voidptr`
+    6 |         p++
+    7 |         p += 3
+    8 |         _ = p - 1
+      |             ^
+    9 |         p--
+   10 |         p -= 3
+vlib/v/checker/tests/pointer_ops.vv:9:4: error: invalid operation: -- (non-numeric type `voidptr`)
+    7 |         p += 3
+    8 |         _ = p - 1
+    9 |         p--
+      |          ~~
+   10 |         p -= 3
+   11 |         _ = p[3]
+vlib/v/checker/tests/pointer_ops.vv:10:3: error: operator `-=` not defined on left operand type `voidptr`
+    8 |         _ = p - 1
+    9 |         p--
+   10 |         p -= 3
+      |         ^
+   11 |         _ = p[3]
+   12 |     }
+vlib/v/checker/tests/pointer_ops.vv:11:8: error: type `voidptr` does not support indexing
+    9 |         p--
+   10 |         p -= 3
+   11 |         _ = p[3]
+      |              ~~~
+   12 |     }
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/pointer_ops.vv b/v_windows/v/old/vlib/v/checker/tests/pointer_ops.vv
new file mode 100644
index 0000000..e93161b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/pointer_ops.vv
@@ -0,0 +1,13 @@
+// void* arithmetic is not allowed in MSVC, so ban it
+fn test_voidptr() {
+	unsafe {
+		mut p := voidptr(0)
+		_ = p + 1
+		p++
+		p += 3
+		_ = p - 1
+		p--
+		p -= 3
+		_ = p[3]
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/prefix_err.out b/v_windows/v/old/vlib/v/checker/tests/prefix_err.out
new file mode 100644
index 0000000..528ddd0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/prefix_err.out
@@ -0,0 +1,95 @@
+vlib/v/checker/tests/prefix_err.vv:5:6: error: cannot take the address of true
+    3 | }
+    4 | 
+    5 | b := &true
+      |      ^
+    6 | _ := &get()
+    7 | _ := &(get())
+vlib/v/checker/tests/prefix_err.vv:6:6: error: cannot take the address of get()
+    4 | 
+    5 | b := &true
+    6 | _ := &get()
+      |      ^
+    7 | _ := &(get())
+    8 | _ := &(get() + 1)
+vlib/v/checker/tests/prefix_err.vv:7:6: error: cannot take the address of get()
+    5 | b := &true
+    6 | _ := &get()
+    7 | _ := &(get())
+      |      ^
+    8 | _ := &(get() + 1)
+    9 | _ := &10
+vlib/v/checker/tests/prefix_err.vv:8:6: error: cannot take the address of get() + 1
+    6 | _ := &get()
+    7 | _ := &(get())
+    8 | _ := &(get() + 1)
+      |      ^
+    9 | _ := &10
+   10 | _ := &"Hi"
+vlib/v/checker/tests/prefix_err.vv:9:6: error: cannot take the address of 10
+    7 | _ := &(get())
+    8 | _ := &(get() + 1)
+    9 | _ := &10
+      |      ^
+   10 | _ := &"Hi"
+   11 | _ := &"${b}"
+vlib/v/checker/tests/prefix_err.vv:10:6: error: cannot take the address of 'Hi'
+    8 | _ := &(get() + 1)
+    9 | _ := &10
+   10 | _ := &"Hi"
+      |      ^
+   11 | _ := &"${b}"
+   12 | _ := &`c`
+vlib/v/checker/tests/prefix_err.vv:11:6: error: cannot take the address of '$b'
+    9 | _ := &10
+   10 | _ := &"Hi"
+   11 | _ := &"${b}"
+      |      ^
+   12 | _ := &`c`
+   13 | _ := &1.2
+vlib/v/checker/tests/prefix_err.vv:12:6: error: cannot take the address of `c`
+   10 | _ := &"Hi"
+   11 | _ := &"${b}"
+   12 | _ := &`c`
+      |      ^
+   13 | _ := &1.2
+   14 | _ := &(1 + 2)
+vlib/v/checker/tests/prefix_err.vv:13:6: error: cannot take the address of 1.2
+   11 | _ := &"${b}"
+   12 | _ := &`c`
+   13 | _ := &1.2
+      |      ^
+   14 | _ := &(1 + 2)
+   15 | _ := 12.3
+vlib/v/checker/tests/prefix_err.vv:14:6: error: cannot take the address of 1 + 2
+   12 | _ := &`c`
+   13 | _ := &1.2
+   14 | _ := &(1 + 2)
+      |      ^
+   15 | _ := 12.3
+   16 |
+vlib/v/checker/tests/prefix_err.vv:18:5: error: invalid indirect of `int`
+   16 | 
+   17 | a := 1
+   18 | _ = *a
+      |     ^
+   19 | a <- 4
+   20 |
+vlib/v/checker/tests/prefix_err.vv:19:1: error: cannot push on non-channel `int`
+   17 | a := 1
+   18 | _ = *a
+   19 | a <- 4
+      | ^
+   20 | 
+   21 | _ = ~true
+vlib/v/checker/tests/prefix_err.vv:21:5: error: operator ~ only defined on int types
+   19 | a <- 4
+   20 | 
+   21 | _ = ~true
+      |     ^
+   22 | _ = !4
+vlib/v/checker/tests/prefix_err.vv:22:5: error: ! operator can only be used with bool types
+   20 | 
+   21 | _ = ~true
+   22 | _ = !4
+      |     ^
diff --git a/v_windows/v/old/vlib/v/checker/tests/prefix_err.vv b/v_windows/v/old/vlib/v/checker/tests/prefix_err.vv
new file mode 100644
index 0000000..6472a0b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/prefix_err.vv
@@ -0,0 +1,22 @@
+fn get() int {
+    return 1
+}
+
+b := &true
+_ := &get()
+_ := &(get())
+_ := &(get() + 1)
+_ := &10
+_ := &"Hi"
+_ := &"${b}"
+_ := &`c`
+_ := &1.2
+_ := &(1 + 2)
+_ := 12.3
+
+a := 1
+_ = *a
+a <- 4
+
+_ = ~true
+_ = !4
diff --git a/v_windows/v/old/vlib/v/checker/tests/prefix_expr_decl_assign_err.out b/v_windows/v/old/vlib/v/checker/tests/prefix_expr_decl_assign_err.out
new file mode 100644
index 0000000..575fc0f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/prefix_expr_decl_assign_err.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/prefix_expr_decl_assign_err.vv:2:5: error: non-name on the left side of `:=`
+    1 | fn main() {
+    2 |     &a := 12
+      |     ^
+    3 |     (*d) := 14
+    4 | }
+vlib/v/checker/tests/prefix_expr_decl_assign_err.vv:3:5: error: non-name `(*d)` on left side of `:=`
+    1 | fn main() {
+    2 |     &a := 12
+    3 |     (*d) := 14
+      |     ~~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/prefix_expr_decl_assign_err.vv b/v_windows/v/old/vlib/v/checker/tests/prefix_expr_decl_assign_err.vv
new file mode 100644
index 0000000..3cfff48
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/prefix_expr_decl_assign_err.vv
@@ -0,0 +1,4 @@
+fn main() {
+    &a := 12
+    (*d) := 14
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/print_char.out b/v_windows/v/old/vlib/v/checker/tests/print_char.out
new file mode 100644
index 0000000..055ec11
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/print_char.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/print_char.vv:1:1: error: `println` cannot print type `char` directly, print its address or cast it to an integer instead
+    1 | println(char(91))
+      | ~~~~~~~~~~~~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/print_char.vv b/v_windows/v/old/vlib/v/checker/tests/print_char.vv
new file mode 100644
index 0000000..9ddba8a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/print_char.vv
@@ -0,0 +1 @@
+println(char(91))
diff --git a/v_windows/v/old/vlib/v/checker/tests/println_can_not_print_void_expressions.out b/v_windows/v/old/vlib/v/checker/tests/println_can_not_print_void_expressions.out
new file mode 100644
index 0000000..674f2a5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/println_can_not_print_void_expressions.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/println_can_not_print_void_expressions.vv:3:2: error: `print` can not print void expressions
+    1 | fn blabla() {}
+    2 | fn main() {
+    3 |     print(blabla())
+      |     ~~~~~~~~~~~~~~~
+    4 |     println(blabla())
+    5 |     eprint(blabla())
+vlib/v/checker/tests/println_can_not_print_void_expressions.vv:4:2: error: `println` can not print void expressions
+    2 | fn main() {
+    3 |     print(blabla())
+    4 |     println(blabla())
+      |     ~~~~~~~~~~~~~~~~~
+    5 |     eprint(blabla())
+    6 |     eprintln(blabla())
+vlib/v/checker/tests/println_can_not_print_void_expressions.vv:5:2: error: `eprint` can not print void expressions
+    3 |     print(blabla())
+    4 |     println(blabla())
+    5 |     eprint(blabla())
+      |     ~~~~~~~~~~~~~~~~
+    6 |     eprintln(blabla())
+    7 | }
+vlib/v/checker/tests/println_can_not_print_void_expressions.vv:6:2: error: `eprintln` can not print void expressions
+    4 |     println(blabla())
+    5 |     eprint(blabla())
+    6 |     eprintln(blabla())
+      |     ~~~~~~~~~~~~~~~~~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/println_can_not_print_void_expressions.vv b/v_windows/v/old/vlib/v/checker/tests/println_can_not_print_void_expressions.vv
new file mode 100644
index 0000000..e412697
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/println_can_not_print_void_expressions.vv
@@ -0,0 +1,7 @@
+fn blabla() {}
+fn main() {
+	print(blabla())
+	println(blabla())
+	eprint(blabla())
+	eprintln(blabla())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/ptr_assign.out b/v_windows/v/old/vlib/v/checker/tests/ptr_assign.out
new file mode 100644
index 0000000..5afa1d2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ptr_assign.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/ptr_assign.vv:3:5: error: cannot assign to `p`: expected `&int`, not `int literal`
+    1 | mut v := 43
+    2 | mut p := &v
+    3 | p = 4
+      |     ^
+    4 | _ = p
diff --git a/v_windows/v/old/vlib/v/checker/tests/ptr_assign.vv b/v_windows/v/old/vlib/v/checker/tests/ptr_assign.vv
new file mode 100644
index 0000000..562f196
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/ptr_assign.vv
@@ -0,0 +1,4 @@
+mut v := 43
+mut p := &v
+p = 4
+_ = p
diff --git a/v_windows/v/old/vlib/v/checker/tests/receiver_unknown_type_single_letter.out b/v_windows/v/old/vlib/v/checker/tests/receiver_unknown_type_single_letter.out
new file mode 100644
index 0000000..667a0d2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/receiver_unknown_type_single_letter.out
@@ -0,0 +1,4 @@
+vlib/v/checker/tests/receiver_unknown_type_single_letter.vv:1:7: error: unknown type `Abc`
+    1 | fn (p Abc) foo() {}
+      |       ~~~
+    2 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/receiver_unknown_type_single_letter.vv b/v_windows/v/old/vlib/v/checker/tests/receiver_unknown_type_single_letter.vv
new file mode 100644
index 0000000..703cf29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/receiver_unknown_type_single_letter.vv
@@ -0,0 +1,2 @@
+fn (p Abc) foo() {}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/recursive_interface_err.out b/v_windows/v/old/vlib/v/checker/tests/recursive_interface_err.out
new file mode 100644
index 0000000..f3ec2a7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/recursive_interface_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/recursive_interface_err.vv:2:6: error: recursive interface fields are not allowed because they cannot be initialised
+    1 | interface Foo {
+    2 |     foo Foo
+      |         ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/recursive_interface_err.vv b/v_windows/v/old/vlib/v/checker/tests/recursive_interface_err.vv
new file mode 100644
index 0000000..74a3dd9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/recursive_interface_err.vv
@@ -0,0 +1,3 @@
+interface Foo {
+	foo Foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/reference_field_must_be_initialized.out b/v_windows/v/old/vlib/v/checker/tests/reference_field_must_be_initialized.out
new file mode 100644
index 0000000..846e5b7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/reference_field_must_be_initialized.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/reference_field_must_be_initialized.vv:8:7: error: reference field `Node.next` must be initialized
+    6 |
+    7 | fn main(){
+    8 |     n := Node{ data: 123 }
+      |          ~~~~~~~~~~~~~~~~~
+    9 |     eprintln('n.data: $n.data')
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/reference_field_must_be_initialized.vv b/v_windows/v/old/vlib/v/checker/tests/reference_field_must_be_initialized.vv
new file mode 100644
index 0000000..a308173
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/reference_field_must_be_initialized.vv
@@ -0,0 +1,10 @@
+module main
+struct Node {
+    data int
+	next &Node
+}
+
+fn main(){
+	n := Node{ data: 123 }
+    eprintln('n.data: $n.data')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/reference_return.out b/v_windows/v/old/vlib/v/checker/tests/reference_return.out
new file mode 100644
index 0000000..4c9b3c2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/reference_return.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/reference_return.vv:6:9: error: fn `f` expects you to return a reference type `&Aa`, but you are returning `Aa` instead
+    4 | 
+    5 | fn f() &Aa {
+    6 |     return Aa{
+      |            ~~~
+    7 |         a: 1
+    8 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/reference_return.vv b/v_windows/v/old/vlib/v/checker/tests/reference_return.vv
new file mode 100644
index 0000000..42c1e5a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/reference_return.vv
@@ -0,0 +1,14 @@
+struct Aa {
+	a int
+}
+
+fn f() &Aa {
+	return Aa{
+		a: 1
+	}
+}
+
+fn main() {
+	x := f()
+	println(x.a)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_count_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/return_count_mismatch.out
new file mode 100644
index 0000000..8182870
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_count_mismatch.out
@@ -0,0 +1,34 @@
+vlib/v/checker/tests/return_count_mismatch.vv:2:9: error: unexpected argument, current function does not return anything
+    1 | fn v() {
+    2 |     return 3
+      |            ^
+    3 | }
+    4 |
+vlib/v/checker/tests/return_count_mismatch.vv:7:2: error: expected `int` argument
+    5 | fn f() int
+    6 | {
+    7 |     return
+      |     ~~~~~~
+    8 | }
+    9 |
+vlib/v/checker/tests/return_count_mismatch.vv:12:2: error: expected `(int, string)` arguments
+   10 | fn g() (int, string)
+   11 | {
+   12 |     return
+      |     ~~~~~~
+   13 | }
+   14 |
+vlib/v/checker/tests/return_count_mismatch.vv:17:2: error: expected 1 argument, but got 2
+   15 | fn ff() int
+   16 | {
+   17 |     return 2, ''
+      |     ~~~~~~~~~~~~
+   18 | }
+   19 |
+vlib/v/checker/tests/return_count_mismatch.vv:22:2: error: expected 2 arguments, but got 1
+   20 | fn gg() (int, string)
+   21 | {
+   22 |     return 3
+      |     ~~~~~~~~
+   23 | }
+   24 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_count_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/return_count_mismatch.vv
new file mode 100644
index 0000000..15f4116
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_count_mismatch.vv
@@ -0,0 +1,24 @@
+fn v() {
+	return 3
+}
+
+fn f() int
+{
+	return
+}
+
+fn g() (int, string)
+{
+	return
+}
+
+fn ff() int
+{
+	return 2, ''
+}
+
+fn gg() (int, string)
+{
+	return 3
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_a.out b/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_a.out
new file mode 100644
index 0000000..ea41c8b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_a.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_duplicate_with_none_err_a.vv:3:2: error: unreachable code
+    1 | fn f() ?bool {
+    2 |     return true
+    3 |     return none
+      |     ~~~~~~~~~~~
+    4 | }
+    5 | fn main() {
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_a.vv
new file mode 100644
index 0000000..c356eb8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_a.vv
@@ -0,0 +1,9 @@
+fn f() ?bool {
+	return true
+	return none
+}
+fn main() {
+	f() or {
+		println('fail')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_b.out b/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_b.out
new file mode 100644
index 0000000..7bc37bb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_b.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_duplicate_with_none_err_b.vv:3:2: error: unreachable code
+    1 | fn f() ?bool {
+    2 |     return none
+    3 |     return true
+      |     ~~~~~~~~~~~
+    4 | }
+    5 | fn main() {
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_b.vv
new file mode 100644
index 0000000..aaf39a1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_duplicate_with_none_err_b.vv
@@ -0,0 +1,9 @@
+fn f() ?bool {
+	return none
+	return true
+}
+fn main() {
+	f() or {
+		println('fail')
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_fixed_array.out b/v_windows/v/old/vlib/v/checker/tests/return_fixed_array.out
new file mode 100644
index 0000000..3ac7df0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_fixed_array.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/return_fixed_array.vv:1:25: error: fixed array cannot be returned by function
+    1 | fn return_fixed_array() [3]int {
+      |                         ~~~~~~
+    2 |     return [1, 2, 3]!
+    3 | }
+vlib/v/checker/tests/return_fixed_array.vv:5:41: error: fixed array cannot be used in multi-return
+    3 | }
+    4 | 
+    5 | fn return_fixed_array_in_multi_return() ([3]int, [3]int) {
+      |                                         ~~~~~~~~~~~~~~~~
+    6 |     return [1, 2, 3]!, [4, 5, 6]!
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_fixed_array.vv b/v_windows/v/old/vlib/v/checker/tests/return_fixed_array.vv
new file mode 100644
index 0000000..dc24da1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_fixed_array.vv
@@ -0,0 +1,7 @@
+fn return_fixed_array() [3]int {
+	return [1, 2, 3]!
+}
+
+fn return_fixed_array_in_multi_return() ([3]int, [3]int) {
+	return [1, 2, 3]!, [4, 5, 6]!
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if.out b/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if.out
new file mode 100644
index 0000000..f8315ac
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_missing_comp_if.vv:3:1: error: missing return at end of function `foo`
+    1 | fn main() {}
+    2 |
+    3 | fn foo() string {
+      | ~~~~~~~~~~~~~~~
+    4 |     $if windows {
+    5 |
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if.vv b/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if.vv
new file mode 100644
index 0000000..e6e6d79
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if.vv
@@ -0,0 +1,9 @@
+fn main() {}
+
+fn foo() string {
+    $if windows {
+
+    } $else {
+        
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if_nested.out b/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if_nested.out
new file mode 100644
index 0000000..4c24e85
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if_nested.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_missing_comp_if_nested.vv:3:1: error: missing return at end of function `foo`
+    1 | fn main() {}
+    2 |
+    3 | fn foo() string {
+      | ~~~~~~~~~~~~~~~
+    4 |     $if windows {
+    5 |         if true {
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if_nested.vv b/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if_nested.vv
new file mode 100644
index 0000000..08fada9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_comp_if_nested.vv
@@ -0,0 +1,17 @@
+fn main() {}
+
+fn foo() string {
+    $if windows {
+        if true {
+
+        } else {
+            return ''
+        }
+    } $else {
+        if true {
+
+        } else {
+            return ''
+        }
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_if_else_simple.out b/v_windows/v/old/vlib/v/checker/tests/return_missing_if_else_simple.out
new file mode 100644
index 0000000..41eb21b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_if_else_simple.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/return_missing_if_else_simple.vv:1:1: error: missing return at end of function `if_no_returns`
+    1 | fn if_no_returns() int {
+      | ~~~~~~~~~~~~~~~~~~~~~~
+    2 |     if true {
+    3 |         println('no return in then')
+vlib/v/checker/tests/return_missing_if_else_simple.vv:10:1: error: missing return at end of function `if_no_return_in_else`
+    8 | }
+    9 | 
+   10 | fn if_no_return_in_else() int {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   11 |     if true {
+   12 |         return 123
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_if_else_simple.vv b/v_windows/v/old/vlib/v/checker/tests/return_missing_if_else_simple.vv
new file mode 100644
index 0000000..802a7d9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_if_else_simple.vv
@@ -0,0 +1,35 @@
+fn if_no_returns() int {
+	if true {
+		println('no return in then')
+	} else {
+		println('no return in else')
+	}
+	println('hello')
+}
+
+fn if_no_return_in_else() int {
+	if true {
+		return 123
+	} else {
+		println('no return in else')
+	}
+	println('hello')
+}
+
+fn if_returns_in_both_branches() int {
+	// The if here always returns, so the function
+	// returns too:
+	if true {
+		return 123
+	} else {
+		return 456
+	}
+	// TODO: should produce a warning/error about a statement after a return.
+	println('hello')
+}
+
+fn main() {
+	println(if_no_returns())
+	println(if_no_return_in_else())
+	println(if_returns_in_both_branches())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_if_match.out b/v_windows/v/old/vlib/v/checker/tests/return_missing_if_match.out
new file mode 100644
index 0000000..d4877d8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_if_match.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_missing_if_match.vv:3:1: error: missing return at end of function `foo`
+    1 | fn main() {}
+    2 |
+    3 | fn foo() string {
+      | ~~~~~~~~~~~~~~~
+    4 |     if true {
+    5 |         match 1 {
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_if_match.vv b/v_windows/v/old/vlib/v/checker/tests/return_missing_if_match.vv
new file mode 100644
index 0000000..88ab70c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_if_match.vv
@@ -0,0 +1,13 @@
+fn main() {}
+
+fn foo() string {
+    if true {
+        match 1 {
+            1 { return '' }
+            2 { }
+            else { return '' }
+        }
+    } else {
+        return ''
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_match_if.out b/v_windows/v/old/vlib/v/checker/tests/return_missing_match_if.out
new file mode 100644
index 0000000..196b321
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_match_if.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_missing_match_if.vv:3:1: error: missing return at end of function `foo`
+    1 | fn main() {}
+    2 |
+    3 | fn foo() string {
+      | ~~~~~~~~~~~~~~~
+    4 |     match 1 {
+    5 |         1 { return '' }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_match_if.vv b/v_windows/v/old/vlib/v/checker/tests/return_missing_match_if.vv
new file mode 100644
index 0000000..4ff9345
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_match_if.vv
@@ -0,0 +1,15 @@
+fn main() {}
+
+fn foo() string {
+    match 1 {
+        1 { return '' }
+        2 {
+            if true {
+                
+            } else {
+                return ''
+            }
+        }
+        else { return '' }
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_match_simple.out b/v_windows/v/old/vlib/v/checker/tests/return_missing_match_simple.out
new file mode 100644
index 0000000..6e8306b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_match_simple.out
@@ -0,0 +1,12 @@
+vlib/v/checker/tests/return_missing_match_simple.vv:4:3: warning: `match` must have at least one non `else` branch
+    2 |     a := 1
+    3 |     match a {
+    4 |         else { println('abc') }
+      |         ~~~~
+    5 |     }
+    6 |     println('hello')
+vlib/v/checker/tests/return_missing_match_simple.vv:1:1: error: missing return at end of function `h`
+    1 | fn h() int {
+      | ~~~~~~~~~~
+    2 |     a := 1
+    3 |     match a {
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_match_simple.vv b/v_windows/v/old/vlib/v/checker/tests/return_missing_match_simple.vv
new file mode 100644
index 0000000..463c2b2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_match_simple.vv
@@ -0,0 +1,12 @@
+fn h() int {
+	a := 1
+	match a {
+		else { println('abc') }
+	}
+	println('hello')
+}
+
+fn main() {
+	d := h()
+	println('h returned: $d')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_nested.out b/v_windows/v/old/vlib/v/checker/tests/return_missing_nested.out
new file mode 100644
index 0000000..fce3245
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_nested.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_missing_nested.vv:3:1: error: missing return at end of function `foo`
+    1 | fn main() {}
+    2 |
+    3 | fn foo() string {
+      | ~~~~~~~~~~~~~~~
+    4 |     if true {
+    5 |         return ''
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_nested.vv b/v_windows/v/old/vlib/v/checker/tests/return_missing_nested.vv
new file mode 100644
index 0000000..41b4c7f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_nested.vv
@@ -0,0 +1,11 @@
+fn main() {}
+
+fn foo() string {
+    if true {
+        return ''
+    } else {
+        if true {
+            return ''
+        }
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_simple.out b/v_windows/v/old/vlib/v/checker/tests/return_missing_simple.out
new file mode 100644
index 0000000..8016345
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_simple.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_missing_simple.vv:3:1: error: missing return at end of function `foo`
+    1 | fn main() {}
+    2 |
+    3 | fn foo() string {
+      | ~~~~~~~~~~~~~~~
+    4 |     if true {
+    5 |         return ''
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_missing_simple.vv b/v_windows/v/old/vlib/v/checker/tests/return_missing_simple.vv
new file mode 100644
index 0000000..ed200fe
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_missing_simple.vv
@@ -0,0 +1,7 @@
+fn main() {}
+
+fn foo() string {
+    if true {
+        return ''
+    } else {}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_ref_as_no_ref_bug.out b/v_windows/v/old/vlib/v/checker/tests/return_ref_as_no_ref_bug.out
new file mode 100644
index 0000000..01b9990
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_ref_as_no_ref_bug.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/return_ref_as_no_ref_bug.vv:11:9: error: fn `return_not_reference` expects you to return a non reference type `BugStruct`, but you are returning `&BugStruct` instead
+    9 | 
+   10 | fn return_not_reference() BugStruct{
+   11 |     return &BugStruct {
+      |            ^
+   12 |         id: 1
+   13 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_ref_as_no_ref_bug.vv b/v_windows/v/old/vlib/v/checker/tests/return_ref_as_no_ref_bug.vv
new file mode 100644
index 0000000..8d04dc9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_ref_as_no_ref_bug.vv
@@ -0,0 +1,14 @@
+struct BugStruct {
+	id	int
+}
+
+fn main() {
+	x := return_not_reference()
+	println(x.id)
+}
+
+fn return_not_reference() BugStruct{
+	return &BugStruct {
+		id: 1
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_type.out b/v_windows/v/old/vlib/v/checker/tests/return_type.out
new file mode 100644
index 0000000..971347c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_type.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/return_type.vv:2:9: error: cannot use `int literal` as type `bool` in return argument
+    1 | fn test() bool {
+    2 |     return 100
+      |            ~~~
+    3 | }
+    4 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_type.vv b/v_windows/v/old/vlib/v/checker/tests/return_type.vv
new file mode 100644
index 0000000..333ec9f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_type.vv
@@ -0,0 +1,5 @@
+fn test() bool {
+	return 100
+}
+
+fn main() {}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if.out b/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if.vv b/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if.vv
new file mode 100644
index 0000000..d6fffe5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if.vv
@@ -0,0 +1,9 @@
+fn main() {}
+
+fn foo() string {
+    $if windows {
+        return ''
+    } $else {
+        return ''
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if_nested.out b/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if_nested.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if_nested.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if_nested.vv b/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if_nested.vv
new file mode 100644
index 0000000..c76e981
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_comp_if_nested.vv
@@ -0,0 +1,17 @@
+fn main() {}
+
+fn foo() string {
+    $if windows {
+        if true {
+            return ''
+        } else {
+            return ''
+        }
+    } $else {
+        if true {
+            return ''
+        } else {
+            return ''
+        }
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_if_match.out b/v_windows/v/old/vlib/v/checker/tests/return_working_if_match.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_if_match.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_if_match.vv b/v_windows/v/old/vlib/v/checker/tests/return_working_if_match.vv
new file mode 100644
index 0000000..5e8d1bf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_if_match.vv
@@ -0,0 +1,13 @@
+fn main() {}
+
+fn foo() string {
+    if true {
+        match 1 {
+            1 { return '' }
+            2 { return '' }
+            else { return '' }
+        }
+    } else {
+        return ''
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_match_if.out b/v_windows/v/old/vlib/v/checker/tests/return_working_match_if.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_match_if.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_match_if.vv b/v_windows/v/old/vlib/v/checker/tests/return_working_match_if.vv
new file mode 100644
index 0000000..2fbbcdf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_match_if.vv
@@ -0,0 +1,15 @@
+fn main() {}
+
+fn foo() string {
+    match 1 {
+        1 { return '' }
+        2 {
+            if true {
+                return ''
+            } else {
+                return ''
+            }
+        }
+        else { return '' }
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_nested.out b/v_windows/v/old/vlib/v/checker/tests/return_working_nested.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_nested.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_nested.vv b/v_windows/v/old/vlib/v/checker/tests/return_working_nested.vv
new file mode 100644
index 0000000..1d72a02
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_nested.vv
@@ -0,0 +1,12 @@
+fn main() {}
+
+fn foo() string {
+    if true {
+        return ''
+    } else {
+        if true {
+            return ''
+        }
+        return ''
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_simple.out b/v_windows/v/old/vlib/v/checker/tests/return_working_simple.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_simple.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_simple.vv b/v_windows/v/old/vlib/v/checker/tests/return_working_simple.vv
new file mode 100644
index 0000000..271e3f6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_simple.vv
@@ -0,0 +1,9 @@
+fn main() {}
+
+fn foo() string {
+    if true {
+        return ''
+    } else {
+        return ''
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_two_if.out b/v_windows/v/old/vlib/v/checker/tests/return_working_two_if.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_two_if.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_two_if.vv b/v_windows/v/old/vlib/v/checker/tests/return_working_two_if.vv
new file mode 100644
index 0000000..a95825f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_two_if.vv
@@ -0,0 +1,17 @@
+fn main() {}
+
+fn foo() string {
+    if true {
+        if true {
+            return ''
+        }
+
+        if true {
+            return ''
+        } else {
+            return ''
+        }
+    } else {
+        return ''
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_unsafe.out b/v_windows/v/old/vlib/v/checker/tests/return_working_unsafe.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_unsafe.out
diff --git a/v_windows/v/old/vlib/v/checker/tests/return_working_unsafe.vv b/v_windows/v/old/vlib/v/checker/tests/return_working_unsafe.vv
new file mode 100644
index 0000000..777b297
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/return_working_unsafe.vv
@@ -0,0 +1,7 @@
+fn main() {}
+
+fn foo() string {
+    unsafe {
+        return ''
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/returns/return_missing_simple.vv b/v_windows/v/old/vlib/v/checker/tests/returns/return_missing_simple.vv
new file mode 100644
index 0000000..ad62212
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/returns/return_missing_simple.vv
@@ -0,0 +1,7 @@
+fn foo() string {
+	if true {
+		return ''
+	} else {
+		
+	}
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_left_type_err.out b/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_left_type_err.out
new file mode 100644
index 0000000..60866d5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_left_type_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/rshift_op_wrong_left_type_err.vv:2:10: error: invalid operation: shift on type `float literal`
+    1 | fn main() {
+    2 |     println(0.5 >> 1)
+      |             ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_left_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_left_type_err.vv
new file mode 100644
index 0000000..5ea5841
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_left_type_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	println(0.5 >> 1)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_right_type_err.out b/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_right_type_err.out
new file mode 100644
index 0000000..7a0c5d9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_right_type_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/rshift_op_wrong_right_type_err.vv:2:15: error: cannot shift non-integer type `float literal` into type `int literal`
+    1 | fn main() {
+    2 |     println(1 >> 0.5)
+      |                  ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_right_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_right_type_err.vv
new file mode 100644
index 0000000..cd55344
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/rshift_op_wrong_right_type_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	println(1 >> 0.5)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/run/noreturn_fn_can_be_used_instead_of_panic.run.out b/v_windows/v/old/vlib/v/checker/tests/run/noreturn_fn_can_be_used_instead_of_panic.run.out
new file mode 100644
index 0000000..f114c07
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/run/noreturn_fn_can_be_used_instead_of_panic.run.out
@@ -0,0 +1 @@
+log_and_die: error: oh no
diff --git a/v_windows/v/old/vlib/v/checker/tests/run/noreturn_fn_can_be_used_instead_of_panic.vv b/v_windows/v/old/vlib/v/checker/tests/run/noreturn_fn_can_be_used_instead_of_panic.vv
new file mode 100644
index 0000000..10cf22c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/run/noreturn_fn_can_be_used_instead_of_panic.vv
@@ -0,0 +1,14 @@
+fn abc() ?int {
+	return error('oh no')
+}
+
+[noreturn]
+fn log_and_die(e IError) {
+	eprintln('${@FN}: error: $e')
+	exit(77)
+}
+
+fn main() {
+	x := abc() or { log_and_die(err) }
+	println(x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/run/unused_variable_warning.run.out b/v_windows/v/old/vlib/v/checker/tests/run/unused_variable_warning.run.out
new file mode 100644
index 0000000..9fa8e3c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/run/unused_variable_warning.run.out
@@ -0,0 +1,15 @@
+vlib/v/checker/tests/run/unused_variable_warning.vv:3:2: warning: unused variable: `a`
+    1 | // NB: this test should compile and run, but it also should produce a compiler warning.
+    2 | fn main() {
+    3 |     a := 1
+      |     ^
+    4 |     b := 2
+    5 |     println('hello')
+vlib/v/checker/tests/run/unused_variable_warning.vv:4:2: warning: unused variable: `b`
+    2 | fn main() {
+    3 |     a := 1
+    4 |     b := 2
+      |     ^
+    5 |     println('hello')
+    6 | }
+hello
diff --git a/v_windows/v/old/vlib/v/checker/tests/run/unused_variable_warning.vv b/v_windows/v/old/vlib/v/checker/tests/run/unused_variable_warning.vv
new file mode 100644
index 0000000..1611e54
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/run/unused_variable_warning.vv
@@ -0,0 +1,6 @@
+// NB: this test should compile and run, but it also should produce a compiler warning.
+fn main() {
+	a := 1
+	b := 2
+	println('hello')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/selective_const_import.out b/v_windows/v/old/vlib/v/checker/tests/selective_const_import.out
new file mode 100644
index 0000000..690fc3c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/selective_const_import.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/selective_const_import.vv:1:15: error: cannot selectively import constant `second` from `time`, import `time` and use `time.second` instead
+    1 | import time { second }
+      |               ~~~~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/selective_const_import.vv b/v_windows/v/old/vlib/v/checker/tests/selective_const_import.vv
new file mode 100644
index 0000000..93e7b2f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/selective_const_import.vv
@@ -0,0 +1 @@
+import time { second }
diff --git a/v_windows/v/old/vlib/v/checker/tests/selector_expr_assign.out b/v_windows/v/old/vlib/v/checker/tests/selector_expr_assign.out
new file mode 100644
index 0000000..9e98006
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/selector_expr_assign.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/selector_expr_assign.vv:7:6: error: struct fields can only be declared during the initialization
+    5 | fn main() {
+    6 |     abc := Abc{}
+    7 |     abc.a := 2
+      |         ^
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/selector_expr_assign.vv b/v_windows/v/old/vlib/v/checker/tests/selector_expr_assign.vv
new file mode 100644
index 0000000..024c869
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/selector_expr_assign.vv
@@ -0,0 +1,8 @@
+struct Abc {
+	a int
+}
+
+fn main() {
+	abc := Abc{}
+	abc.a := 2
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/selector_expr_optional_err.out b/v_windows/v/old/vlib/v/checker/tests/selector_expr_optional_err.out
new file mode 100644
index 0000000..51065b7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/selector_expr_optional_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/selector_expr_optional_err.vv:4:46: error: cannot access fields of an optional, handle the error with `or {...}` or propagate it with `?`
+    2 | 
+    3 | fn main() {
+    4 |     println(http.get('https://httpbin.org/').status_code)
+      |                                              ~~~~~~~~~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/selector_expr_optional_err.vv b/v_windows/v/old/vlib/v/checker/tests/selector_expr_optional_err.vv
new file mode 100644
index 0000000..d277787
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/selector_expr_optional_err.vv
@@ -0,0 +1,5 @@
+import net.http
+
+fn main() {
+    println(http.get('https://httpbin.org/').status_code)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/shared_bad_args.out b/v_windows/v/old/vlib/v/checker/tests/shared_bad_args.out
new file mode 100644
index 0000000..e41873c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shared_bad_args.out
@@ -0,0 +1,83 @@
+vlib/v/checker/tests/shared_bad_args.vv:43:8: error: `r` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut receiver
+   41 |     shared r := Qr{ a: 7 }
+   42 |     lock s {
+   43 |         u := r.s_val(s)
+      |              ^
+   44 |         println(u)
+   45 |     }
+vlib/v/checker/tests/shared_bad_args.vv:47:16: error: `s` is `shared` and must be `rlock`ed or `lock`ed to be passed as non-mut argument
+   45 |     }
+   46 |     lock r {
+   47 |         v := r.s_val(s)
+      |                      ^
+   48 |         println(v)
+   49 |     }
+vlib/v/checker/tests/shared_bad_args.vv:50:13: error: `m` is `shared` and must be `rlock`ed or `lock`ed to be passed as non-mut argument
+   48 |         println(v)
+   49 |     }
+   50 |     w := m_val(m)
+      |                ^
+   51 |     x := a_val(a)
+   52 |     println('$w $x')
+vlib/v/checker/tests/shared_bad_args.vv:51:13: error: `a` is `shared` and must be `rlock`ed or `lock`ed to be passed as non-mut argument
+   49 |     }
+   50 |     w := m_val(m)
+   51 |     x := a_val(a)
+      |                ^
+   52 |     println('$w $x')
+   53 | }
+vlib/v/checker/tests/shared_bad_args.vv:61:3: error: r must be added to the `lock` list above
+   59 |     shared r := Qr{ a: 7 }
+   60 |     lock s {
+   61 |         r.s_mut(mut s)
+      |         ^
+   62 |     }
+   63 |     lock r {
+vlib/v/checker/tests/shared_bad_args.vv:64:15: error: s must be added to the `lock` list above
+   62 |     }
+   63 |     lock r {
+   64 |         r.s_mut(mut s)
+      |                     ^
+   65 |     }
+   66 |     m_mut(mut m)
+vlib/v/checker/tests/shared_bad_args.vv:66:12: error: m is `shared` and must be `lock`ed to be passed as `mut`
+   64 |         r.s_mut(mut s)
+   65 |     }
+   66 |     m_mut(mut m)
+      |               ^
+   67 |     a_mut(mut a)
+   68 | }
+vlib/v/checker/tests/shared_bad_args.vv:67:12: error: a is `shared` and must be `lock`ed to be passed as `mut`
+   65 |     }
+   66 |     m_mut(mut m)
+   67 |     a_mut(mut a)
+      |               ^
+   68 | }
+   69 |
+vlib/v/checker/tests/shared_bad_args.vv:76:10: error: `y` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut argument to print
+   74 | fn main() {
+   75 |     shared y := St{ a: 5 }
+   76 |     println(y)
+      |             ^
+   77 |     println('$y')
+   78 |     a := Ab{ s: St{ a: 3 } }
+vlib/v/checker/tests/shared_bad_args.vv:77:12: error: `y` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut interpolation object
+   75 |     shared y := St{ a: 5 }
+   76 |     println(y)
+   77 |     println('$y')
+      |               ^
+   78 |     a := Ab{ s: St{ a: 3 } }
+   79 |     println(a.s)
+vlib/v/checker/tests/shared_bad_args.vv:79:12: error: `a.s` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut argument to print
+   77 |     println('$y')
+   78 |     a := Ab{ s: St{ a: 3 } }
+   79 |     println(a.s)
+      |               ^
+   80 |     println('$a.s')
+   81 | }
+vlib/v/checker/tests/shared_bad_args.vv:80:14: error: `a.s` is `shared` and must be `rlock`ed or `lock`ed to be used as non-mut interpolation object
+   78 |     a := Ab{ s: St{ a: 3 } }
+   79 |     println(a.s)
+   80 |     println('$a.s')
+      |                 ^
+   81 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/shared_bad_args.vv b/v_windows/v/old/vlib/v/checker/tests/shared_bad_args.vv
new file mode 100644
index 0000000..f0d4913
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shared_bad_args.vv
@@ -0,0 +1,81 @@
+struct St {
+mut:
+	a int
+}
+
+struct Qr {
+mut:
+	a int
+}
+
+fn (mut r Qr) s_mut(mut s St) {
+	r.a = 5
+	s.a = 7
+}
+
+fn (r Qr) s_val(s St) int {
+	return r.a * s.a
+}
+
+fn m_mut(mut a map[string]f64) {
+	a['yxcv'] = -2.25
+}
+
+fn m_val(a map[string]f64) f64 {
+	x := a['yxcv']
+	return x
+}
+
+fn a_mut(mut a []int) {
+	a[2] = 42
+}
+
+fn a_val(a []int) int {
+	return a[1]
+}
+
+fn test_shared_as_value() {
+	shared s := St{ a: 5 }
+	shared a := [3, 4, 6, 13, -23]
+	shared m := map{'qw': 12.75, 'yxcv': -3.125, 'poiu': 88.0625}
+	shared r := Qr{ a: 7 }
+	lock s {
+		u := r.s_val(s)
+		println(u)
+	}
+	lock r {
+		v := r.s_val(s)
+		println(v)
+	}
+	w := m_val(m)
+	x := a_val(a)
+	println('$w $x')
+}
+
+fn test_shared_as_mut() {
+	shared s := St{ a: 5 }
+	shared a := [3, 4, 6, 13, -23]
+	shared m := map{'qw': 12.75, 'yxcv': -3.125, 'poiu': 88.0625}
+	shared r := Qr{ a: 7 }
+	lock s {
+		r.s_mut(mut s)
+	}
+	lock r {
+		r.s_mut(mut s)
+	}
+	m_mut(mut m)
+	a_mut(mut a)
+}
+
+struct Ab {
+	s shared St
+}
+
+fn main() {
+	shared y := St{ a: 5 }
+	println(y)
+	println('$y')
+	a := Ab{ s: St{ a: 3 } }
+	println(a.s)
+	println('$a.s')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/shared_element_lock.out b/v_windows/v/old/vlib/v/checker/tests/shared_element_lock.out
new file mode 100644
index 0000000..f392a1f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shared_element_lock.out
@@ -0,0 +1,27 @@
+vlib/v/checker/tests/shared_element_lock.vv:36:5: error: `pr.pe` is `shared` and needs explicit lock for `v.ast.SelectorExpr`
+   34 |         }
+   35 |     }
+   36 |     pr.pe.color = 3
+      |        ~~
+   37 |     shared y := pr.pe
+   38 |     rlock y {
+vlib/v/checker/tests/shared_element_lock.vv:42:2: error: `g` is `shared` and needs explicit lock for `v.ast.SelectorExpr`
+   40 |     }
+   41 |     shared g := Pro{}
+   42 |     g.pers.age = 42
+      |     ^
+   43 |     mut h := []shared Pro{len: 3}
+   44 |     h[2].pers.age = 42
+vlib/v/checker/tests/shared_element_lock.vv:44:2: error: you have to create a handle and `lock` it to modify `shared` array element
+   42 |     g.pers.age = 42
+   43 |     mut h := []shared Pro{len: 3}
+   44 |     h[2].pers.age = 42
+      |     ~~~~
+   45 |     println(h[2].pers.age)
+   46 | }
+vlib/v/checker/tests/shared_element_lock.vv:45:10: error: you have to create a handle and `rlock` it to use a `shared` element as non-mut argument to print
+   43 |     mut h := []shared Pro{len: 3}
+   44 |     h[2].pers.age = 42
+   45 |     println(h[2].pers.age)
+      |             ~~~~
+   46 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/shared_element_lock.vv b/v_windows/v/old/vlib/v/checker/tests/shared_element_lock.vv
new file mode 100644
index 0000000..de61ad9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shared_element_lock.vv
@@ -0,0 +1,46 @@
+struct Person {
+mut:
+    name string
+    age int
+}
+
+struct Pet {
+mut:
+    name string
+    color int
+}
+
+struct Programmer {
+mut:
+	pers Person
+	pe shared Pet
+}
+
+struct Pro {
+mut:
+	pers Person
+	pe Pet
+}
+
+fn main() {
+	mut pr := Programmer{
+		pers: Person{
+			name: 'Qwe'
+			age: 44
+		}
+		pe: Pet{
+			name: 'Ghj'
+			color: 7
+		}
+	}
+	pr.pe.color = 3
+	shared y := pr.pe
+	rlock y {
+		println(y.color)
+	}
+	shared g := Pro{}
+	g.pers.age = 42
+	mut h := []shared Pro{len: 3}
+	h[2].pers.age = 42
+	println(h[2].pers.age)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/shared_lock.out b/v_windows/v/old/vlib/v/checker/tests/shared_lock.out
new file mode 100644
index 0000000..62d7130
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shared_lock.out
@@ -0,0 +1,21 @@
+vlib/v/checker/tests/shared_lock.vv:19:5: error: method with `shared` receiver cannot be called inside `lock`/`rlock` block
+   17 |     }
+   18 |     lock x {
+   19 |         x.r(x)
+      |           ~~~~
+   20 |         x.m(x)
+   21 |         f(0, x)
+vlib/v/checker/tests/shared_lock.vv:20:7: error: method with `shared` arguments cannot be called inside `lock`/`rlock` block
+   18 |     lock x {
+   19 |         x.r(x)
+   20 |         x.m(x)
+      |             ^
+   21 |         f(0, x)
+   22 |     }
+vlib/v/checker/tests/shared_lock.vv:21:8: error: function with `shared` arguments cannot be called inside `lock`/`rlock` block
+   19 |         x.r(x)
+   20 |         x.m(x)
+   21 |         f(0, x)
+      |              ^
+   22 |     }
+   23 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/shared_lock.vv b/v_windows/v/old/vlib/v/checker/tests/shared_lock.vv
new file mode 100644
index 0000000..9af8111
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shared_lock.vv
@@ -0,0 +1,23 @@
+struct St {
+mut:
+	a int
+}
+fn (shared s St) r(x St) {
+}
+fn (s St) m(shared x St) {
+}
+
+
+fn f(w int, shared x St) {
+}
+
+fn g() {
+	shared x := St{
+		a: 5
+	}
+	lock x {
+		x.r(x)
+		x.m(x)
+		f(0, x)
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/shared_type_mismatch.out b/v_windows/v/old/vlib/v/checker/tests/shared_type_mismatch.out
new file mode 100644
index 0000000..32e16d9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shared_type_mismatch.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/shared_type_mismatch.vv:13:3: error: wrong return type `St` in the `or {}` block, expected `shared St`
+   11 | fn test_shared_opt_bad() {
+   12 |     shared yy := f() or {
+   13 |         St{ x: 37.5 }
+      |         ~~~~~~~~~~~~~
+   14 |     }
+   15 |     rlock yy {
diff --git a/v_windows/v/old/vlib/v/checker/tests/shared_type_mismatch.vv b/v_windows/v/old/vlib/v/checker/tests/shared_type_mismatch.vv
new file mode 100644
index 0000000..9d85636
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shared_type_mismatch.vv
@@ -0,0 +1,18 @@
+struct St {
+mut:
+	x f64
+}
+
+fn f() ?shared St {
+	shared x := St{ x: 12.75 }
+	return x
+}
+
+fn test_shared_opt_bad() {
+	shared yy := f() or {
+		St{ x: 37.5 }
+	}
+	rlock yy {
+	    println(yy.x)
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_left_type_err.out b/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_left_type_err.out
new file mode 100644
index 0000000..1bdeb5e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_left_type_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/shift_op_wrong_left_type_err.vv:2:10: error: invalid operation: shift on type `float literal`
+    1 | fn main() {
+    2 |     println(0.5 << 1)
+      |             ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_left_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_left_type_err.vv
new file mode 100644
index 0000000..87409eb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_left_type_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	println(0.5 << 1)
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_right_type_err.out b/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_right_type_err.out
new file mode 100644
index 0000000..87d0a44
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_right_type_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/shift_op_wrong_right_type_err.vv:2:15: error: cannot shift non-integer type `float literal` into type `int literal`
+    1 | fn main() {
+    2 |     println(1 << 0.5)
+      |                  ~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_right_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_right_type_err.vv
new file mode 100644
index 0000000..0eb1328
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/shift_op_wrong_right_type_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+	println(1 << 0.5)
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/short_struct_wrong_number.out b/v_windows/v/old/vlib/v/checker/tests/short_struct_wrong_number.out
new file mode 100644
index 0000000..fa6044b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/short_struct_wrong_number.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/short_struct_wrong_number.vv:7:6: error: too few fields in `Test` literal (expecting 2, got 1)
+    5 |
+    6 | fn main() {
+    7 |     _ = Test{true}
+      |         ~~~~~~~~~~
+    8 |     _ = Test{true, false, true}
+    9 | }
+vlib/v/checker/tests/short_struct_wrong_number.vv:8:6: error: too many fields in `Test` literal (expecting 2, got 3)
+    6 | fn main() {
+    7 |     _ = Test{true}
+    8 |     _ = Test{true, false, true}
+      |         ~~~~~~~~~~~~~~~~~~~~~~~
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/short_struct_wrong_number.vv b/v_windows/v/old/vlib/v/checker/tests/short_struct_wrong_number.vv
new file mode 100644
index 0000000..393ca5e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/short_struct_wrong_number.vv
@@ -0,0 +1,9 @@
+struct Test {
+	foo bool
+	bar bool
+}
+
+fn main() {
+	_ = Test{true}
+	_ = Test{true, false, true}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/slice_reassignment.out b/v_windows/v/old/vlib/v/checker/tests/slice_reassignment.out
new file mode 100644
index 0000000..7ab478f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/slice_reassignment.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/slice_reassignment.vv:3:5: error: cannot reassign using range expression on the left side of an assignment
+    1 | fn main() {
+    2 |     mut arr := [1, 2, 3, 4, 5]
+    3 |     arr[..2] = [0, 0]
+      |        ~~~~~
+    4 |     println(arr)
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/slice_reassignment.vv b/v_windows/v/old/vlib/v/checker/tests/slice_reassignment.vv
new file mode 100644
index 0000000..602bd64
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/slice_reassignment.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut arr := [1, 2, 3, 4, 5]
+	arr[..2] = [0, 0]
+	println(arr)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/sort_method_called_on_immutable_receiver.out b/v_windows/v/old/vlib/v/checker/tests/sort_method_called_on_immutable_receiver.out
new file mode 100644
index 0000000..d588267
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sort_method_called_on_immutable_receiver.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/sort_method_called_on_immutable_receiver.vv:2:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    1 | fn abc (a []int) {
+    2 |     a.sort()
+      |     ^
+    3 | }
+    4 |
+vlib/v/checker/tests/sort_method_called_on_immutable_receiver.vv:7:2: error: `a` is immutable, declare it with `mut` to make it mutable
+    5 | fn main() {
+    6 |     a := [2,30,10,20,1]
+    7 |     a.sort(a>b)
+      |     ^
+    8 |     eprintln(' a: $a')
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/sort_method_called_on_immutable_receiver.vv b/v_windows/v/old/vlib/v/checker/tests/sort_method_called_on_immutable_receiver.vv
new file mode 100644
index 0000000..b2dafa5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sort_method_called_on_immutable_receiver.vv
@@ -0,0 +1,9 @@
+fn abc (a []int) {
+	a.sort()
+}
+
+fn main() {
+	a := [2,30,10,20,1]
+	a.sort(a>b)
+	eprintln(' a: $a')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/static_vars_in_translated_mode.out b/v_windows/v/old/vlib/v/checker/tests/static_vars_in_translated_mode.out
new file mode 100644
index 0000000..18c297a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/static_vars_in_translated_mode.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/static_vars_in_translated_mode.vv:2:13: error: static variables are supported only in -translated mode or in [unsafe] fn
+    1 | fn counter() int {
+    2 |     mut static icounter := 0
+      |                ~~~~~~~~
+    3 |     icounter++
+    4 |     return icounter
diff --git a/v_windows/v/old/vlib/v/checker/tests/static_vars_in_translated_mode.vv b/v_windows/v/old/vlib/v/checker/tests/static_vars_in_translated_mode.vv
new file mode 100644
index 0000000..0f153c8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/static_vars_in_translated_mode.vv
@@ -0,0 +1,12 @@
+fn counter() int {
+	mut static icounter := 0
+	icounter++
+	return icounter
+}
+
+fn main() {
+	println(unsafe { counter() })
+	println(unsafe { counter() })
+	println(unsafe { counter() })
+	println(unsafe { counter() })
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/store_string_err.out b/v_windows/v/old/vlib/v/checker/tests/store_string_err.out
new file mode 100644
index 0000000..b0a44bf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/store_string_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/store_string_err.vv:5:26: error: wrong return type `IError` in the `or {}` block, expected `int`
+    3 | }
+    4 | 
+    5 | err := return_err() or { err }
+      |                          ~~~
+    6 | eprintln(err)
diff --git a/v_windows/v/old/vlib/v/checker/tests/store_string_err.vv b/v_windows/v/old/vlib/v/checker/tests/store_string_err.vv
new file mode 100644
index 0000000..7f8b3ff
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/store_string_err.vv
@@ -0,0 +1,6 @@
+fn return_err() ?int {
+	return error('')
+}
+
+err := return_err() or { err }
+eprintln(err)
diff --git a/v_windows/v/old/vlib/v/checker/tests/str_method_0_arguments.out b/v_windows/v/old/vlib/v/checker/tests/str_method_0_arguments.out
new file mode 100644
index 0000000..9b8f1df
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/str_method_0_arguments.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/str_method_0_arguments.vv:5:1: error: .str() methods should have 0 arguments 
+    3 | }
+    4 | 
+    5 | fn (z Zzz) str(x int) string {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    6 |     return 'z: $z.x'
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/str_method_0_arguments.vv b/v_windows/v/old/vlib/v/checker/tests/str_method_0_arguments.vv
new file mode 100644
index 0000000..28ef0ef
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/str_method_0_arguments.vv
@@ -0,0 +1,11 @@
+struct Zzz {
+	x int
+}
+
+fn (z Zzz) str(x int) string {
+    return 'z: $z.x'
+}
+
+fn main() {
+	println(Zzz{123})
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/str_method_return_string.out b/v_windows/v/old/vlib/v/checker/tests/str_method_return_string.out
new file mode 100644
index 0000000..43bb36a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/str_method_return_string.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/str_method_return_string.vv:5:1: error: .str() methods should return `string` 
+    3 | }
+    4 | 
+    5 | fn (z Zzz) str(x int) int {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~
+    6 |     return z.x
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/str_method_return_string.vv b/v_windows/v/old/vlib/v/checker/tests/str_method_return_string.vv
new file mode 100644
index 0000000..a3f6952
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/str_method_return_string.vv
@@ -0,0 +1,11 @@
+struct Zzz {
+	x int
+}
+
+fn (z Zzz) str(x int) int {
+	return z.x
+}
+
+fn main() {
+	println(Zzz{123})
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_char_null_err.out b/v_windows/v/old/vlib/v/checker/tests/string_char_null_err.out
new file mode 100644
index 0000000..60e1f7a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_char_null_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/string_char_null_err.vv:2:31: error: cannot use `\0` (NULL character) in the string literal
+    1 | fn main() {
+    2 |     println('Null character: \0')
+      |                               ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_char_null_err.vv b/v_windows/v/old/vlib/v/checker/tests/string_char_null_err.vv
new file mode 100644
index 0000000..d60854f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_char_null_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println('Null character: \0')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_a.out b/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_a.out
new file mode 100644
index 0000000..607c240
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_a.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/string_escape_u_err_a.vv:2:15: error: `\u` incomplete unicode character value
+    1 | fn main() {
+    2 |     println('\u')
+      |               ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_a.vv
new file mode 100644
index 0000000..ad7aee7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_a.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println('\u')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_b.out b/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_b.out
new file mode 100644
index 0000000..d81d688
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_b.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/string_escape_u_err_b.vv:2:15: error: `\u` incomplete unicode character value
+    1 | fn main() {
+    2 |     println('\u345')
+      |               ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_b.vv
new file mode 100644
index 0000000..650f8d6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_escape_u_err_b.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println('\u345')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_a.out b/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_a.out
new file mode 100644
index 0000000..f441565
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_a.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/string_escape_x_err_a.vv:2:15: error: `\x` used with no following hex digits
+    1 | fn main() {
+    2 |     println('\x')
+      |               ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_a.vv
new file mode 100644
index 0000000..fdbd44b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_a.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println('\x')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_b.out b/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_b.out
new file mode 100644
index 0000000..da90fd1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_b.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/string_escape_x_err_b.vv:2:15: error: `\x` used with no following hex digits
+    1 | fn main() {
+    2 |     println('\xhh')
+      |               ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_b.vv
new file mode 100644
index 0000000..deabe28
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_escape_x_err_b.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println('\xhh')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_index_assign_error.out b/v_windows/v/old/vlib/v/checker/tests/string_index_assign_error.out
new file mode 100644
index 0000000..be9369e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_index_assign_error.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/string_index_assign_error.vv:3:6: error: cannot assign to s[i] since V strings are immutable
+(note, that variables may be mutable but string values are always immutable, like in Go and Java)
+    1 | fn main() {
+    2 |     mut a := 'V is great!!'
+    3 |     a[0] = `R`
+      |      ~~~
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_index_assign_error.vv b/v_windows/v/old/vlib/v/checker/tests/string_index_assign_error.vv
new file mode 100644
index 0000000..161b215
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_index_assign_error.vv
@@ -0,0 +1,4 @@
+fn main() {
+    mut a := 'V is great!!'
+    a[0] = `R`
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_index_non_int_err.out b/v_windows/v/old/vlib/v/checker/tests/string_index_non_int_err.out
new file mode 100644
index 0000000..81e574a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_index_non_int_err.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/string_index_non_int_err.vv:3:14: error: non-integer string index `string`
+    1 | fn main() {
+    2 |     v := 'foo'
+    3 |     println(v['f'])
+      |              ~~~~~
+    4 |     println(v[true])
+    5 |     println(v[[23]])
+vlib/v/checker/tests/string_index_non_int_err.vv:4:14: error: non-integer string index `bool`
+    2 |     v := 'foo'
+    3 |     println(v['f'])
+    4 |     println(v[true])
+      |              ~~~~~~
+    5 |     println(v[[23]])
+    6 | }
+vlib/v/checker/tests/string_index_non_int_err.vv:5:14: error: non-integer string index `[]int`
+    3 |     println(v['f'])
+    4 |     println(v[true])
+    5 |     println(v[[23]])
+      |              ~~~~~~
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_index_non_int_err.vv b/v_windows/v/old/vlib/v/checker/tests/string_index_non_int_err.vv
new file mode 100644
index 0000000..6619e47
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_index_non_int_err.vv
@@ -0,0 +1,6 @@
+fn main() {
+    v := 'foo'
+    println(v['f'])
+    println(v[true])
+    println(v[[23]])
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_interpolation_invalid_fmt.out b/v_windows/v/old/vlib/v/checker/tests/string_interpolation_invalid_fmt.out
new file mode 100644
index 0000000..6ac3efe
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_interpolation_invalid_fmt.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/string_interpolation_invalid_fmt.vv:3:12: error: format specifier may only be one letter 
+    1 | fn interpolate_wrong() string {
+    2 |     a := 5
+    3 |     x := '${a:xy}'
+      |               ~~
+    4 |     return x
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_interpolation_invalid_fmt.vv b/v_windows/v/old/vlib/v/checker/tests/string_interpolation_invalid_fmt.vv
new file mode 100644
index 0000000..bfc8db4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_interpolation_invalid_fmt.vv
@@ -0,0 +1,5 @@
+fn interpolate_wrong() string {
+	a := 5
+	x := '${a:xy}'
+	return x
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_interpolation_wrong_fmt.out b/v_windows/v/old/vlib/v/checker/tests/string_interpolation_wrong_fmt.out
new file mode 100644
index 0000000..4c9d7ae
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_interpolation_wrong_fmt.out
@@ -0,0 +1,63 @@
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:3:16: error: precision specification only valid for float types 
+    1 | fn interpolate_str() string {
+    2 |     a := 'hallo'
+    3 |     x := '>${a:8.3s}<'
+      |                   ^
+    4 |     y := '${a:G}'
+    5 |     z := '${a:d}'
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:4:12: error: illegal format specifier `G` for type `string` 
+    2 |     a := 'hallo'
+    3 |     x := '>${a:8.3s}<'
+    4 |     y := '${a:G}'
+      |               ^
+    5 |     z := '${a:d}'
+    6 |     return x + y + z
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:5:12: error: illegal format specifier `d` for type `string` 
+    3 |     x := '>${a:8.3s}<'
+    4 |     y := '${a:G}'
+    5 |     z := '${a:d}'
+      |               ^
+    6 |     return x + y + z
+    7 | }
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:11:15: error: illegal format specifier `s` for type `f64` 
+    9 | fn interpolate_f64() string {
+   10 |     b := 1367.57
+   11 |     x := '>${b:20s}<'
+      |                  ^
+   12 |     y := '${b:d}'
+   13 |     return x + y
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:12:12: error: illegal format specifier `d` for type `f64` 
+   10 |     b := 1367.57
+   11 |     x := '>${b:20s}<'
+   12 |     y := '${b:d}'
+      |               ^
+   13 |     return x + y
+   14 | }
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:19:14: error: illegal format specifier `d` for type `u32` 
+   17 |     u := u32(15)
+   18 |     s := -12
+   19 |     x := '${u:13d}'
+      |                 ^
+   20 |     y := '${s:04u}'
+   21 |     z := '${s:f}'
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:20:14: error: illegal format specifier `u` for type `int` 
+   18 |     s := -12
+   19 |     x := '${u:13d}'
+   20 |     y := '${s:04u}'
+      |                 ^
+   21 |     z := '${s:f}'
+   22 |     q := '${u:v}'
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:21:12: error: illegal format specifier `f` for type `int` 
+   19 |     x := '${u:13d}'
+   20 |     y := '${s:04u}'
+   21 |     z := '${s:f}'
+      |               ^
+   22 |     q := '${u:v}'
+   23 |     return x + y + z + q
+vlib/v/checker/tests/string_interpolation_wrong_fmt.vv:22:12: error: unknown format specifier `v` 
+   20 |     y := '${s:04u}'
+   21 |     z := '${s:f}'
+   22 |     q := '${u:v}'
+      |               ^
+   23 |     return x + y + z + q
+   24 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/string_interpolation_wrong_fmt.vv b/v_windows/v/old/vlib/v/checker/tests/string_interpolation_wrong_fmt.vv
new file mode 100644
index 0000000..38aa5f3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/string_interpolation_wrong_fmt.vv
@@ -0,0 +1,24 @@
+fn interpolate_str() string {
+	a := 'hallo'
+	x := '>${a:8.3s}<'
+	y := '${a:G}'
+	z := '${a:d}'
+	return x + y + z
+}
+
+fn interpolate_f64() string {
+	b := 1367.57
+	x := '>${b:20s}<'
+	y := '${b:d}'
+	return x + y
+}
+
+fn interpolate_int() string {
+	u := u32(15)
+	s := -12
+	x := '${u:13d}'
+	y := '${s:04u}'
+	z := '${s:f}'
+	q := '${u:v}'
+	return x + y + z + q
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_assigned_to_pointer_to_struct.out b/v_windows/v/old/vlib/v/checker/tests/struct_assigned_to_pointer_to_struct.out
new file mode 100644
index 0000000..54b047e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_assigned_to_pointer_to_struct.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/struct_assigned_to_pointer_to_struct.vv:5:4: error: mismatched types `&Foo` and `Foo`
+    3 | fn main() {
+    4 |     mut f := &Foo{ 10 }
+    5 |     f = Foo{ x: 20 }
+      |       ^
+    6 |     _ = f
+    7 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_assigned_to_pointer_to_struct.vv b/v_windows/v/old/vlib/v/checker/tests/struct_assigned_to_pointer_to_struct.vv
new file mode 100644
index 0000000..5e96349
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_assigned_to_pointer_to_struct.vv
@@ -0,0 +1,7 @@
+struct Foo { x int }
+
+fn main() {
+	mut f := &Foo{ 10 }
+	f = Foo{ x: 20 }
+	_ = f
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_generic_err.out b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_generic_err.out
new file mode 100644
index 0000000..62cb81a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_generic_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/struct_cast_to_struct_generic_err.vv:11:7: error: casting to struct is deprecated, use e.g. `Struct{...expr}` instead
+    9 | fn main() {
+   10 |     abc := Abc<int>{}
+   11 |     _ := Xyz(abc)
+      |          ~~~~~~~~
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_generic_err.vv b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_generic_err.vv
new file mode 100644
index 0000000..ce81ba5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_generic_err.vv
@@ -0,0 +1,12 @@
+struct Abc<T> {
+	name T
+}
+
+struct Xyz {
+	name string
+}
+
+fn main() {
+	abc := Abc<int>{}
+	_ := Xyz(abc)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_a.out b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_a.out
new file mode 100644
index 0000000..baafe70
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_a.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/struct_cast_to_struct_mut_err_a.vv:12:7: error: casting to struct is deprecated, use e.g. `Struct{...expr}` instead
+   10 | fn main() {
+   11 |     abc := Abc{}
+   12 |     _ := Xyz(abc)
+      |          ~~~~~~~~
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_a.vv
new file mode 100644
index 0000000..7a5e4a3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_a.vv
@@ -0,0 +1,13 @@
+struct Abc {
+mut:
+	name string
+}
+
+struct Xyz {
+	name string
+}
+
+fn main() {
+	abc := Abc{}
+	_ := Xyz(abc)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_b.out b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_b.out
new file mode 100644
index 0000000..aa6f232
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_b.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/struct_cast_to_struct_mut_err_b.vv:12:7: error: casting to struct is deprecated, use e.g. `Struct{...expr}` instead
+   10 | fn main() {
+   11 |     abc := Abc{}
+   12 |     _ := Xyz(abc)
+      |          ~~~~~~~~
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_b.vv
new file mode 100644
index 0000000..ff34dca
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_mut_err_b.vv
@@ -0,0 +1,13 @@
+struct Abc {
+	name string
+}
+
+struct Xyz {
+mut:
+	name string
+}
+
+fn main() {
+	abc := Abc{}
+	_ := Xyz(abc)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_a.out b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_a.out
new file mode 100644
index 0000000..0a2778b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_a.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/struct_cast_to_struct_pub_err_a.vv:12:7: error: casting to struct is deprecated, use e.g. `Struct{...expr}` instead
+   10 | fn main() {
+   11 |     abc := Abc{}
+   12 |     _ := Xyz(abc)
+      |          ~~~~~~~~
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_a.vv
new file mode 100644
index 0000000..7c559e4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_a.vv
@@ -0,0 +1,13 @@
+struct Abc {
+pub:
+	name string
+}
+
+struct Xyz {
+	name string
+}
+
+fn main() {
+	abc := Abc{}
+	_ := Xyz(abc)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_b.out b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_b.out
new file mode 100644
index 0000000..bbc7e33
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_b.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/struct_cast_to_struct_pub_err_b.vv:12:7: error: casting to struct is deprecated, use e.g. `Struct{...expr}` instead
+   10 | fn main() {
+   11 |     abc := Abc{}
+   12 |     _ := Xyz(abc)
+      |          ~~~~~~~~
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_b.vv
new file mode 100644
index 0000000..aa92278
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_cast_to_struct_pub_err_b.vv
@@ -0,0 +1,13 @@
+struct Abc {
+	name string
+}
+
+struct Xyz {
+pub:
+	name string
+}
+
+fn main() {
+	abc := Abc{}
+	_ := Xyz(abc)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_embed_invalid_type.out b/v_windows/v/old/vlib/v/checker/tests/struct_embed_invalid_type.out
new file mode 100644
index 0000000..d85190f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_embed_invalid_type.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/struct_embed_invalid_type.vv:4:2: error: `Foo` is not a struct
+    2 |
+    3 | struct Bar {
+    4 |     Foo
+      |     ~~~
+    5 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_embed_invalid_type.vv b/v_windows/v/old/vlib/v/checker/tests/struct_embed_invalid_type.vv
new file mode 100644
index 0000000..13f3c52
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_embed_invalid_type.vv
@@ -0,0 +1,5 @@
+type Foo = int
+
+struct Bar {
+	Foo
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_field_name_duplicate_err.out b/v_windows/v/old/vlib/v/checker/tests/struct_field_name_duplicate_err.out
new file mode 100644
index 0000000..691268c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_field_name_duplicate_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/struct_field_name_duplicate_err.vv:3:2: error: field name `a` duplicate
+    1 | struct Aaa {
+    2 |     a int
+    3 |     a string
+      |     ~~~~~~~~
+    4 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_field_name_duplicate_err.vv b/v_windows/v/old/vlib/v/checker/tests/struct_field_name_duplicate_err.vv
new file mode 100644
index 0000000..487b0a7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_field_name_duplicate_err.vv
@@ -0,0 +1,4 @@
+struct Aaa {
+	a int
+	a string
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_field_type_err.out b/v_windows/v/old/vlib/v/checker/tests/struct_field_type_err.out
new file mode 100644
index 0000000..6c8e6df
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_field_type_err.out
@@ -0,0 +1,43 @@
+vlib/v/checker/tests/struct_field_type_err.vv:12:3: error: cannot assign to field `n`: expected `int`, not `bool`
+   10 | fn main() {
+   11 |     mut data := Data{
+   12 |         n: true
+      |         ~~~~~~~
+   13 |         b: 0
+   14 |         f1: fn (v ...voidptr) {}
+vlib/v/checker/tests/struct_field_type_err.vv:13:3: error: cannot assign to field `b`: expected `bool`, not `int literal`
+   11 |     mut data := Data{
+   12 |         n: true
+   13 |         b: 0
+      |         ~~~~
+   14 |         f1: fn (v ...voidptr) {}
+   15 |         f2: fn (v voidptr) {}
+vlib/v/checker/tests/struct_field_type_err.vv:14:3: error: cannot assign to field `f1`: expected `fn (voidptr)`, not `fn (...voidptr)`
+   12 |         n: true
+   13 |         b: 0
+   14 |         f1: fn (v ...voidptr) {}
+      |         ~~~~~~~~~~~~~~~~~~~~~~~~
+   15 |         f2: fn (v voidptr) {}
+   16 |         data: true
+Details: ``'s expected fn argument: `` is a pointer, but the passed fn argument: `v` is NOT a pointer
+vlib/v/checker/tests/struct_field_type_err.vv:15:3: error: cannot assign to field `f2`: expected `fn (...voidptr)`, not `fn (voidptr)`
+   13 |         b: 0
+   14 |         f1: fn (v ...voidptr) {}
+   15 |         f2: fn (v voidptr) {}
+      |         ~~~~~~~~~~~~~~~~~~~~~
+   16 |         data: true
+   17 |     }
+Details: ``'s expected fn argument: `` is NOT a pointer, but the passed fn argument: `v` is a pointer
+vlib/v/checker/tests/struct_field_type_err.vv:16:3: error: cannot assign to field `data`: expected `&Data`, not `bool`
+   14 |         f1: fn (v ...voidptr) {}
+   15 |         f2: fn (v voidptr) {}
+   16 |         data: true
+      |         ~~~~~~~~~~
+   17 |     }
+   18 |
+vlib/v/checker/tests/struct_field_type_err.vv:19:11: error: cannot assign to `data.n`: expected `int`, not `bool`
+   17 |     }
+   18 | 
+   19 |     data.n = true
+      |              ~~~~
+   20 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_field_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/struct_field_type_err.vv
new file mode 100644
index 0000000..44850c2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_field_type_err.vv
@@ -0,0 +1,20 @@
+struct Data {
+mut:
+	n    int
+	b    bool
+	f1   fn (voidptr)
+	f2   fn (...voidptr)
+	data &Data
+}
+
+fn main() {
+	mut data := Data{
+		n: true
+		b: 0
+		f1: fn (v ...voidptr) {}
+		f2: fn (v voidptr) {}
+		data: true
+	}
+
+	data.n = true
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_init_update_type_err.out b/v_windows/v/old/vlib/v/checker/tests/struct_init_update_type_err.out
new file mode 100644
index 0000000..c0eab9e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_init_update_type_err.out
@@ -0,0 +1,35 @@
+vlib/v/checker/tests/struct_init_update_type_err.vv:11:6: error: expected struct, found `int`
+    9 |     i := 2
+   10 |     _ := Foo{
+   11 |         ...i
+      |            ^
+   12 |         name: 'f2'
+   13 |     }
+vlib/v/checker/tests/struct_init_update_type_err.vv:16:6: error: expected struct, found `&int`
+   14 |     p := &i
+   15 |     _ = Foo{
+   16 |         ...p
+      |            ^
+   17 |     }
+   18 |     f2 := Foo2{}
+vlib/v/checker/tests/struct_init_update_type_err.vv:20:6: error: struct `Foo2` is not compatible with struct `Foo`
+   18 |     f2 := Foo2{}
+   19 |     _ = Foo{
+   20 |         ...f2
+      |            ~~
+   21 |     }
+   22 |     _ = Foo{
+vlib/v/checker/tests/struct_init_update_type_err.vv:23:6: error: expression is not an lvalue
+   21 |     }
+   22 |     _ = Foo{
+   23 |         ...Foo{}
+      |            ~~~~~
+   24 |     }
+   25 | }
+vlib/v/checker/tests/struct_init_update_type_err.vv:32:6: error: struct `Empty` is not compatible with struct `Foo`
+   30 |     e := Empty{}
+   31 |     _ = Foo{
+   32 |         ...e
+      |            ^
+   33 |     }
+   34 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_init_update_type_err.vv b/v_windows/v/old/vlib/v/checker/tests/struct_init_update_type_err.vv
new file mode 100644
index 0000000..6f8deeb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_init_update_type_err.vv
@@ -0,0 +1,35 @@
+struct Foo {
+	name string
+	age int
+}
+
+struct Foo2 {b bool}
+
+fn main() {
+	i := 2
+	_ := Foo{
+		...i
+		name: 'f2'
+	}
+	p := &i
+	_ = Foo{
+		...p
+	}
+	f2 := Foo2{}
+	_ = Foo{
+		...f2
+	}
+	_ = Foo{
+		...Foo{}
+	}
+}
+
+struct Empty {}
+
+fn empty() {
+	e := Empty{}
+	_ = Foo{
+		...e
+	}
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_pub_field.out b/v_windows/v/old/vlib/v/checker/tests/struct_pub_field.out
new file mode 100644
index 0000000..c0c34c7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_pub_field.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/struct_pub_field.vv:9:4: error: field `i` of struct `Foo` is immutable
+    7 |         i: 1
+    8 |     }
+    9 |     a.i = 2
+      |       ^
+   10 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_pub_field.vv b/v_windows/v/old/vlib/v/checker/tests/struct_pub_field.vv
new file mode 100644
index 0000000..1f104ca
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_pub_field.vv
@@ -0,0 +1,10 @@
+struct Foo {
+	i int
+}
+
+fn main() {
+	a := Foo{
+		i: 1
+	}
+	a.i = 2
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_required_field.out b/v_windows/v/old/vlib/v/checker/tests/struct_required_field.out
new file mode 100644
index 0000000..212ca63
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_required_field.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/struct_required_field.vv:12:6: error: field `Abc.f3` must be initialized
+   10 |         f3: 789
+   11 |     }
+   12 |     _ = Abc{
+      |         ~~~~
+   13 |         f1: 123
+   14 |         f2: 789
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_required_field.vv b/v_windows/v/old/vlib/v/checker/tests/struct_required_field.vv
new file mode 100644
index 0000000..85b2a4d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_required_field.vv
@@ -0,0 +1,16 @@
+struct Abc {
+	f1 int [required]
+	f2 int
+	f3 int [required]
+}
+
+fn main() {
+	_ = Abc{
+		f1: 123
+		f3: 789
+	}
+	_ = Abc{
+		f1: 123
+		f2: 789
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_required_fn_field.out b/v_windows/v/old/vlib/v/checker/tests/struct_required_fn_field.out
new file mode 100644
index 0000000..25d6ee8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_required_fn_field.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/struct_required_fn_field.vv:12:6: error: field `Abc.f3` must be initialized
+   10 |         f3: fn () {}
+   11 |     }
+   12 |     _ = Abc{
+      |         ~~~~
+   13 |         f1: 123
+   14 |         f2: 789
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_required_fn_field.vv b/v_windows/v/old/vlib/v/checker/tests/struct_required_fn_field.vv
new file mode 100644
index 0000000..e72cfe6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_required_fn_field.vv
@@ -0,0 +1,16 @@
+struct Abc {
+	f1 int [required]
+	f2 int
+	f3 fn () [attr1; required; attr2]
+}
+
+fn main() {
+	_ = Abc{
+		f1: 123
+		f3: fn () {}
+	}
+	_ = Abc{
+		f1: 123
+		f2: 789
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_short_init_warning.out b/v_windows/v/old/vlib/v/checker/tests/struct_short_init_warning.out
new file mode 100644
index 0000000..41daa52
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_short_init_warning.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/struct_short_init_warning.vv:6:9: warning: short struct initalization is deprecated, use explicit struct name
+    4 |
+    5 | fn f(foo Foo) Foo {
+    6 |     return {v: foo.v}
+      |            ~~~~~~~~~~
+    7 | }
+    8 |
+vlib/v/checker/tests/struct_short_init_warning.vv:10:4: warning: short struct initalization is deprecated, use explicit struct name
+    8 |
+    9 | fn main() {
+   10 |     f({v: 10})
+      |       ~~~~~~~
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_short_init_warning.vv b/v_windows/v/old/vlib/v/checker/tests/struct_short_init_warning.vv
new file mode 100644
index 0000000..74bd02f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_short_init_warning.vv
@@ -0,0 +1,11 @@
+struct Foo {
+	v int
+}
+
+fn f(foo Foo) Foo {
+	return {v: foo.v}
+}
+
+fn main() {
+	f({v: 10})
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_type_cast_err.out b/v_windows/v/old/vlib/v/checker/tests/struct_type_cast_err.out
new file mode 100644
index 0000000..4648a27
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_type_cast_err.out
@@ -0,0 +1,63 @@
+vlib/v/checker/tests/struct_type_cast_err.vv:5:10: error: cannot cast struct to `string`
+    3 | fn main() {
+    4 |     foo := Foo{}
+    5 |     _ := string(foo)
+      |          ~~~~~~~~~~~
+    6 |     _ := int(foo)
+    7 |     _ := u64(foo)
+vlib/v/checker/tests/struct_type_cast_err.vv:6:10: error: cannot cast struct to `int`
+    4 |     foo := Foo{}
+    5 |     _ := string(foo)
+    6 |     _ := int(foo)
+      |          ~~~~~~~~
+    7 |     _ := u64(foo)
+    8 |     _ := u32(foo)
+vlib/v/checker/tests/struct_type_cast_err.vv:7:10: error: cannot cast struct to `u64`
+    5 |     _ := string(foo)
+    6 |     _ := int(foo)
+    7 |     _ := u64(foo)
+      |          ~~~~~~~~
+    8 |     _ := u32(foo)
+    9 |     _ := rune(foo)
+vlib/v/checker/tests/struct_type_cast_err.vv:8:10: error: cannot cast struct to `u32`
+    6 |     _ := int(foo)
+    7 |     _ := u64(foo)
+    8 |     _ := u32(foo)
+      |          ~~~~~~~~
+    9 |     _ := rune(foo)
+   10 |     _ := byte(foo)
+vlib/v/checker/tests/struct_type_cast_err.vv:9:10: error: cannot cast struct to `rune`
+    7 |     _ := u64(foo)
+    8 |     _ := u32(foo)
+    9 |     _ := rune(foo)
+      |          ~~~~~~~~~
+   10 |     _ := byte(foo)
+   11 |     _ := i8(foo)
+vlib/v/checker/tests/struct_type_cast_err.vv:10:10: error: cannot cast type `Foo` to `byte`
+    8 |     _ := u32(foo)
+    9 |     _ := rune(foo)
+   10 |     _ := byte(foo)
+      |          ~~~~~~~~~
+   11 |     _ := i8(foo)
+   12 |     _ := i64(foo)
+vlib/v/checker/tests/struct_type_cast_err.vv:11:10: error: cannot cast struct to `i8`
+    9 |     _ := rune(foo)
+   10 |     _ := byte(foo)
+   11 |     _ := i8(foo)
+      |          ~~~~~~~
+   12 |     _ := i64(foo)
+   13 |     _ := int(foo)
+vlib/v/checker/tests/struct_type_cast_err.vv:12:10: error: cannot cast struct to `i64`
+   10 |     _ := byte(foo)
+   11 |     _ := i8(foo)
+   12 |     _ := i64(foo)
+      |          ~~~~~~~~
+   13 |     _ := int(foo)
+   14 |     _ = &I1(foo)
+vlib/v/checker/tests/struct_type_cast_err.vv:13:10: error: cannot cast struct to `int`
+   11 |     _ := i8(foo)
+   12 |     _ := i64(foo)
+   13 |     _ := int(foo)
+      |          ~~~~~~~~
+   14 |     _ = &I1(foo)
+   15 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_type_cast_err.vv b/v_windows/v/old/vlib/v/checker/tests/struct_type_cast_err.vv
new file mode 100644
index 0000000..a27eefd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_type_cast_err.vv
@@ -0,0 +1,17 @@
+struct Foo{}
+
+fn main() {
+    foo := Foo{}
+    _ := string(foo)
+    _ := int(foo)
+    _ := u64(foo)
+    _ := u32(foo)
+    _ := rune(foo)
+    _ := byte(foo)
+    _ := i8(foo)
+    _ := i64(foo)
+    _ := int(foo)
+    _ = &I1(foo)
+}
+
+interface I1{}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_unknown_field.out b/v_windows/v/old/vlib/v/checker/tests/struct_unknown_field.out
new file mode 100644
index 0000000..2c544b0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_unknown_field.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/struct_unknown_field.vv:8:3: error: unknown field `bar` in struct literal of type `Test`
+    6 |     t := Test{
+    7 |         foo: true
+    8 |         bar: false
+      |         ~~~~~~~~~~
+    9 |     }
+   10 |     _ = t
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_unknown_field.vv b/v_windows/v/old/vlib/v/checker/tests/struct_unknown_field.vv
new file mode 100644
index 0000000..018bcef
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_unknown_field.vv
@@ -0,0 +1,11 @@
+struct Test {
+	foo bool
+}
+
+fn main() {
+	t := Test{
+		foo: true
+		bar: false
+	}
+	_ = t
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_unneeded_default.out b/v_windows/v/old/vlib/v/checker/tests/struct_unneeded_default.out
new file mode 100644
index 0000000..029f9fe
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_unneeded_default.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/struct_unneeded_default.vv:2:10: error: unnecessary default value of `0`: struct fields are zeroed by default
+    1 | struct Test {
+    2 |     n int = 0
+      |             ^
+    3 |     s string = ''
+    4 |     b bool = false
+vlib/v/checker/tests/struct_unneeded_default.vv:3:13: error: unnecessary default value of '': struct fields are zeroed by default
+    1 | struct Test {
+    2 |     n int = 0
+    3 |     s string = ''
+      |                ~~
+    4 |     b bool = false
+    5 | }
+vlib/v/checker/tests/struct_unneeded_default.vv:4:11: error: unnecessary default value `false`: struct fields are zeroed by default
+    2 |     n int = 0
+    3 |     s string = ''
+    4 |     b bool = false
+      |              ~~~~~
+    5 | }
+    6 |
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/struct_unneeded_default.vv b/v_windows/v/old/vlib/v/checker/tests/struct_unneeded_default.vv
new file mode 100644
index 0000000..7ddc066
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/struct_unneeded_default.vv
@@ -0,0 +1,8 @@
+struct Test {
+	n int = 0
+	s string = ''
+	b bool = false
+}
+
+fn main() {
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum.out b/v_windows/v/old/vlib/v/checker/tests/sum.out
new file mode 100644
index 0000000..5c92692
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum.out
@@ -0,0 +1,28 @@
+vlib/v/checker/tests/sum.vv:5:8: error: cannot cast non-sum type `int` using `as`
+    3 | fn non_sum() {
+    4 |     v := 4
+    5 |     _ = v as rune
+      |           ~~
+    6 |     _ = v as Var
+    7 | }
+vlib/v/checker/tests/sum.vv:6:8: error: cannot cast non-sum type `int` using `as` - use e.g. `Var(some_expr)` instead.
+    4 |     v := 4
+    5 |     _ = v as rune
+    6 |     _ = v as Var
+      |           ~~
+    7 | }
+    8 |
+vlib/v/checker/tests/sum.vv:10:7: error: cannot cast `rune` to `Var`
+    8 | 
+    9 | fn sum() {
+   10 |     _ := Var(`J`)
+      |          ~~~~~~~~
+   11 |     mut s2 := Var('')
+   12 |     s2 = true
+vlib/v/checker/tests/sum.vv:12:7: error: cannot assign to `s2`: expected `Var`, not `bool`
+   10 |     _ := Var(`J`)
+   11 |     mut s2 := Var('')
+   12 |     s2 = true
+      |          ~~~~
+   13 |     _ = s2
+   14 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum.vv b/v_windows/v/old/vlib/v/checker/tests/sum.vv
new file mode 100644
index 0000000..6796a2e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum.vv
@@ -0,0 +1,14 @@
+type Var = int | string
+
+fn non_sum() {
+	v := 4
+	_ = v as rune
+	_ = v as Var
+}
+
+fn sum() {
+	_ := Var(`J`)
+	mut s2 := Var('')
+	s2 = true
+	_ = s2
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_assign_non_variant_err.out b/v_windows/v/old/vlib/v/checker/tests/sum_type_assign_non_variant_err.out
new file mode 100644
index 0000000..1a9ea99
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_assign_non_variant_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/sum_type_assign_non_variant_err.vv:11:6: error: cannot assign to `w`: expected `Stmt`, not `IfExpr`
+    9 | fn main() {
+   10 |     mut w := Stmt(AnotherThing{})
+   11 |     w = IfExpr{}
+      |         ~~~~~~~~
+   12 |     _ = w
+   13 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_assign_non_variant_err.vv b/v_windows/v/old/vlib/v/checker/tests/sum_type_assign_non_variant_err.vv
new file mode 100644
index 0000000..1ab9a2c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_assign_non_variant_err.vv
@@ -0,0 +1,13 @@
+type Expr = IfExpr | CallExpr | MatchExpr
+struct MatchExpr {}
+struct IfExpr {}
+struct CallExpr {}
+
+type Stmt = Expr | AnotherThing
+struct AnotherThing {}
+
+fn main() {
+    mut w := Stmt(AnotherThing{})
+	w = IfExpr{}
+	_ = w
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_alias_error.out b/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_alias_error.out
new file mode 100644
index 0000000..20c3b00
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_alias_error.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/sum_type_common_fields_alias_error.vv:35:14: error: field `name` does not exist or have the same type in all sumtype variants
+   33 |     }
+   34 |     println(m)
+   35 |     assert m[0].name == 'abc'
+      |                 ~~~~
+   36 |     assert m[1].name == 'def'
+   37 |     assert m[2].name == 'xyz'
+vlib/v/checker/tests/sum_type_common_fields_alias_error.vv:36:14: error: field `name` does not exist or have the same type in all sumtype variants
+   34 |     println(m)
+   35 |     assert m[0].name == 'abc'
+   36 |     assert m[1].name == 'def'
+      |                 ~~~~
+   37 |     assert m[2].name == 'xyz'
+   38 | }
+vlib/v/checker/tests/sum_type_common_fields_alias_error.vv:37:14: error: field `name` does not exist or have the same type in all sumtype variants
+   35 |     assert m[0].name == 'abc'
+   36 |     assert m[1].name == 'def'
+   37 |     assert m[2].name == 'xyz'
+      |                 ~~~~
+   38 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_alias_error.vv b/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_alias_error.vv
new file mode 100644
index 0000000..9a296b8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_alias_error.vv
@@ -0,0 +1,38 @@
+type Main = Sub1 | Sub2 | Sub3
+
+// NB: the subtypes will have a common `name` field, of the same `string`
+// type, except Sub3, which has `name` of type AliasedString.
+
+type AliasedString = string
+
+struct Sub1 {
+mut:
+	name string
+}
+
+struct Sub2 {
+mut:
+	name string
+}
+
+struct Sub3 {
+mut:
+	name AliasedString
+}
+
+fn main() {
+	mut m := []Main{}
+	m << Sub1{
+		name: 'abc'
+	}
+	m << Sub2{
+		name: 'def'
+	}
+	m << Sub3{
+		name: 'xyz'
+	}
+	println(m)
+	assert m[0].name == 'abc'
+	assert m[1].name == 'def'
+	assert m[2].name == 'xyz'
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_error.out b/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_error.out
new file mode 100644
index 0000000..9dce91a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_error.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/sum_type_common_fields_error.vv:53:14: error: field `val` does not exist or have the same type in all sumtype variants
+   51 |     assert m[2].name == '64bit integer'
+   52 |     assert m[3].name == 'string'
+   53 |     assert m[0].val == 123
+      |                 ~~~
+   54 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_error.vv b/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_error.vv
new file mode 100644
index 0000000..2da560a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_common_fields_error.vv
@@ -0,0 +1,54 @@
+type Main = Sub1 | Sub2 | Sub3 | Sub4
+
+// NB: all subtypes have a common name field, of the same `string` type
+// but they also have a field `val` that is of a different type in the
+// different subtypes => accessing `m[0].name` is fine, but *not* `m[0].val`
+struct Sub1 {
+mut:
+	val  int
+	name string
+}
+
+struct Sub2 {
+mut:
+	val  f32
+	name string
+}
+
+struct Sub3 {
+mut:
+	val  i64
+	name string
+}
+
+struct Sub4 {
+mut:
+	val  string
+	name string
+}
+
+fn main() {
+	mut m := []Main{}
+	m << Sub1{
+		val: 123
+		name: 'integer'
+	}
+	m << Sub2{
+		val: 3.14
+		name: 'float'
+	}
+	m << Sub3{
+		val: 9_876_543_210
+		name: '64bit integer'
+	}
+	m << Sub4{
+		val: 'abcd'
+		name: 'string'
+	}
+	println(m)
+	assert m[0].name == 'integer'
+	assert m[1].name == 'float'
+	assert m[2].name == '64bit integer'
+	assert m[3].name == 'string'
+	assert m[0].val == 123
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_exists.out b/v_windows/v/old/vlib/v/checker/tests/sum_type_exists.out
new file mode 100644
index 0000000..a580ba0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_exists.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/sum_type_exists.vv:1:22: error: unknown type `Inexistant`
+    1 | type Miscellaneous = Inexistant | Nope | int
+      |                      ~~~~~~~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_exists.vv b/v_windows/v/old/vlib/v/checker/tests/sum_type_exists.vv
new file mode 100644
index 0000000..28a4475
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_exists.vv
@@ -0,0 +1 @@
+type Miscellaneous = Inexistant | Nope | int
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_infix_err.out b/v_windows/v/old/vlib/v/checker/tests/sum_type_infix_err.out
new file mode 100644
index 0000000..6a06f1b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_infix_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/sum_type_infix_err.vv:5:9: error: cannot use operator `+` with `Abc`
+    3 | fn main() {
+    4 |     x := Abc(0)
+    5 |     _ := x + Abc(5)
+      |            ^
+    6 |     _ := 123 + x
+    7 |     _ = unsafe{&x + 5}
+vlib/v/checker/tests/sum_type_infix_err.vv:6:11: error: cannot use operator `+` with `Abc`
+    4 |     x := Abc(0)
+    5 |     _ := x + Abc(5)
+    6 |     _ := 123 + x
+      |              ^
+    7 |     _ = unsafe{&x + 5}
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_infix_err.vv b/v_windows/v/old/vlib/v/checker/tests/sum_type_infix_err.vv
new file mode 100644
index 0000000..938dd6f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_infix_err.vv
@@ -0,0 +1,8 @@
+type Abc = int | string
+
+fn main() {
+	x := Abc(0)
+	_ := x + Abc(5)
+	_ := 123 + x
+	_ = unsafe{&x + 5}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_multiple_type_define.out b/v_windows/v/old/vlib/v/checker/tests/sum_type_multiple_type_define.out
new file mode 100644
index 0000000..7052f3b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_multiple_type_define.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/sum_type_multiple_type_define.vv:3:22: error: sum type FooType cannot hold the type `Foo` more than once
+    1 | struct Foo {}
+    2 |
+    3 | type FooType = Foo | Foo
+      |                      ~~~
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_multiple_type_define.vv b/v_windows/v/old/vlib/v/checker/tests/sum_type_multiple_type_define.vv
new file mode 100644
index 0000000..7ec43d0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_multiple_type_define.vv
@@ -0,0 +1,3 @@
+struct Foo {}
+
+type FooType = Foo | Foo
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_mutable_cast_err.out b/v_windows/v/old/vlib/v/checker/tests/sum_type_mutable_cast_err.out
new file mode 100644
index 0000000..a880221
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_mutable_cast_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/sum_type_mutable_cast_err.vv:15:10: error: cannot use operator `+` with `Abc`
+   13 |     mut x := Abc(0)
+   14 |     if x is int {
+   15 |         _ := x + 5
+      |                ^
+   16 |     }
+   17 |     mut f := Foo{Bar{Abc(0)}}
+vlib/v/checker/tests/sum_type_mutable_cast_err.vv:19:14: error: cannot use operator `+` with `Abc`
+   17 |     mut f := Foo{Bar{Abc(0)}}
+   18 |     if f.b.a is int {
+   19 |         _ := f.b.a + 5
+      |                    ^
+   20 |     }
+   21 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_mutable_cast_err.vv b/v_windows/v/old/vlib/v/checker/tests/sum_type_mutable_cast_err.vv
new file mode 100644
index 0000000..d122a12
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_mutable_cast_err.vv
@@ -0,0 +1,21 @@
+type Abc = int | string
+
+struct Bar {
+mut:
+	a Abc
+}
+
+struct Foo {
+	b Bar
+}
+
+fn main() {
+	mut x := Abc(0)
+	if x is int {
+		_ := x + 5
+	}
+	mut f := Foo{Bar{Abc(0)}}
+	if f.b.a is int {
+		_ := f.b.a + 5
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_ref_variant_err.out b/v_windows/v/old/vlib/v/checker/tests/sum_type_ref_variant_err.out
new file mode 100644
index 0000000..d893a2b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_ref_variant_err.out
@@ -0,0 +1,18 @@
+vlib/v/checker/tests/sum_type_ref_variant_err.vv:7:33: error: sum type cannot hold a reference type
+    5 |     foo string
+    6 | }
+    7 | type Alphabet1 = Abc | string | &Xyz
+      |                                 ~~~~
+    8 | type Alphabet2 = Abc | &Xyz | string
+    9 | type Alphabet3 = &Xyz | Abc | string
+vlib/v/checker/tests/sum_type_ref_variant_err.vv:8:24: error: sum type cannot hold a reference type
+    6 | }
+    7 | type Alphabet1 = Abc | string | &Xyz
+    8 | type Alphabet2 = Abc | &Xyz | string
+      |                        ~~~~
+    9 | type Alphabet3 = &Xyz | Abc | string
+vlib/v/checker/tests/sum_type_ref_variant_err.vv:9:18: error: sum type cannot hold a reference type
+    7 | type Alphabet1 = Abc | string | &Xyz
+    8 | type Alphabet2 = Abc | &Xyz | string
+    9 | type Alphabet3 = &Xyz | Abc | string
+      |                  ~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/sum_type_ref_variant_err.vv b/v_windows/v/old/vlib/v/checker/tests/sum_type_ref_variant_err.vv
new file mode 100644
index 0000000..def2a54
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sum_type_ref_variant_err.vv
@@ -0,0 +1,9 @@
+struct Abc {
+    val string
+}
+struct Xyz {
+    foo string
+}
+type Alphabet1 = Abc | string | &Xyz
+type Alphabet2 = Abc | &Xyz | string
+type Alphabet3 = &Xyz | Abc | string
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/sumtype_in_sumtype_err.out b/v_windows/v/old/vlib/v/checker/tests/sumtype_in_sumtype_err.out
new file mode 100644
index 0000000..f491079
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sumtype_in_sumtype_err.out
@@ -0,0 +1,3 @@
+vlib/v/checker/tests/sumtype_in_sumtype_err.vv:1:11: error: sum type cannot hold itself
+    1 | type AA = AA | int
+      |           ~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/sumtype_in_sumtype_err.vv b/v_windows/v/old/vlib/v/checker/tests/sumtype_in_sumtype_err.vv
new file mode 100644
index 0000000..7e53df8
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sumtype_in_sumtype_err.vv
@@ -0,0 +1 @@
+type AA = AA | int
diff --git a/v_windows/v/old/vlib/v/checker/tests/sumtype_mismatched_type.out b/v_windows/v/old/vlib/v/checker/tests/sumtype_mismatched_type.out
new file mode 100644
index 0000000..813f472
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sumtype_mismatched_type.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/sumtype_mismatched_type.vv:4:8: error: infix expr: cannot use `int literal` (right expression) as `AA`
+    2 | 
+    3 | a := AA(3)
+    4 | assert a == 3
+      |        ~~~~~~
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/sumtype_mismatched_type.vv b/v_windows/v/old/vlib/v/checker/tests/sumtype_mismatched_type.vv
new file mode 100644
index 0000000..d6a998b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/sumtype_mismatched_type.vv
@@ -0,0 +1,4 @@
+type AA = int | string
+
+a := AA(3)
+assert a == 3
diff --git a/v_windows/v/old/vlib/v/checker/tests/templates/index.html b/v_windows/v/old/vlib/v/checker/tests/templates/index.html
new file mode 100644
index 0000000..7624de1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/templates/index.html
@@ -0,0 +1 @@
+@test
diff --git a/v_windows/v/old/vlib/v/checker/tests/test_functions_should_not_return_test.out b/v_windows/v/old/vlib/v/checker/tests/test_functions_should_not_return_test.out
new file mode 100644
index 0000000..0972921
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/test_functions_should_not_return_test.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/test_functions_should_not_return_test.vv:9:1: error: test functions should either return nothing at all, or be marked to return `?`
+    7 | 
+    8 | // should be disallowed:
+    9 | fn test_returning_int() int {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   10 | 
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/test_functions_should_not_return_test.vv b/v_windows/v/old/vlib/v/checker/tests/test_functions_should_not_return_test.vv
new file mode 100644
index 0000000..3bebcea
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/test_functions_should_not_return_test.vv
@@ -0,0 +1,17 @@
+// ordinary functions can return whatever they like,
+// since they are not called by V's testing system
+// in the generated main():
+fn abc() int {
+	return 1
+}
+
+// should be disallowed:
+fn test_returning_int() int {
+
+}
+
+// NB: this is allowed explicitly now, to allow for shorter tests
+// of functions returning optionals.
+fn test_returning_opt() ? {
+	assert true
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/trailing_comma_struct_attr.out b/v_windows/v/old/vlib/v/checker/tests/trailing_comma_struct_attr.out
new file mode 100644
index 0000000..eed55bd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/trailing_comma_struct_attr.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/trailing_comma_struct_attr.vv:3:31: error: unexpected token `]`, expecting name
+    1 | struct User {
+    2 |     name string
+    3 |     jobs []string [json:jobss;]
+      |                               ^
+    4 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/trailing_comma_struct_attr.vv b/v_windows/v/old/vlib/v/checker/tests/trailing_comma_struct_attr.vv
new file mode 100644
index 0000000..d20a3d4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/trailing_comma_struct_attr.vv
@@ -0,0 +1,4 @@
+struct User {
+    name string
+    jobs []string [json:jobss;]
+}
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/type_cast_optional_err.out b/v_windows/v/old/vlib/v/checker/tests/type_cast_optional_err.out
new file mode 100644
index 0000000..bb52bad
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/type_cast_optional_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/type_cast_optional_err.vv:2:13: error: cannot type cast an optional
+    1 | fn main() {
+    2 |     println(int('hi'.last_index('i')))
+      |             ~~~~~~~~~~~~~~~~~~~~~~~~~
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/type_cast_optional_err.vv b/v_windows/v/old/vlib/v/checker/tests/type_cast_optional_err.vv
new file mode 100644
index 0000000..982559c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/type_cast_optional_err.vv
@@ -0,0 +1,3 @@
+fn main() {
+    println(int('hi'.last_index('i')))
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/typedef_attr_v_struct_err.out b/v_windows/v/old/vlib/v/checker/tests/typedef_attr_v_struct_err.out
new file mode 100644
index 0000000..0253fba
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/typedef_attr_v_struct_err.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/typedef_attr_v_struct_err.vv:2:1: error: `typedef` attribute can only be used with C structs
+    1 | [typedef]
+    2 | struct Point{}
+      | ~~~~~~~~~~~~
+    3 | 
+    4 | fn main() {
diff --git a/v_windows/v/old/vlib/v/checker/tests/typedef_attr_v_struct_err.vv b/v_windows/v/old/vlib/v/checker/tests/typedef_attr_v_struct_err.vv
new file mode 100644
index 0000000..421b635
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/typedef_attr_v_struct_err.vv
@@ -0,0 +1,7 @@
+[typedef]
+struct Point{}
+
+fn main() {
+    p := Point{}
+    println(p)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/undefined_ident_of_struct.out b/v_windows/v/old/vlib/v/checker/tests/undefined_ident_of_struct.out
new file mode 100644
index 0000000..35e0a6c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/undefined_ident_of_struct.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/undefined_ident_of_struct.vv:4:2: error: undefined ident: `f`
+    2 |
+    3 | fn get()  {
+    4 |     f.a = 'test'
+      |     ^
+    5 | }
+    6 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/undefined_ident_of_struct.vv b/v_windows/v/old/vlib/v/checker/tests/undefined_ident_of_struct.vv
new file mode 100644
index 0000000..a426195
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/undefined_ident_of_struct.vv
@@ -0,0 +1,9 @@
+module main
+
+fn get()  {
+	f.a = 'test'
+}
+
+fn main() {
+	println('hello')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unexpected_or.out b/v_windows/v/old/vlib/v/checker/tests/unexpected_or.out
new file mode 100644
index 0000000..ab1e077
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unexpected_or.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unexpected_or.vv:6:17: error: unexpected `or` block, the function `ret_zero` does not return an optional
+    4 | 
+    5 | fn main() {
+    6 |     _ = ret_zero() or { 1 }
+      |                    ~~~~~~~~
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unexpected_or.vv b/v_windows/v/old/vlib/v/checker/tests/unexpected_or.vv
new file mode 100644
index 0000000..48a8696
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unexpected_or.vv
@@ -0,0 +1,7 @@
+fn ret_zero() int {
+	return 0
+}
+
+fn main() {
+	_ = ret_zero() or { 1 }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unexpected_or_propagate.out b/v_windows/v/old/vlib/v/checker/tests/unexpected_or_propagate.out
new file mode 100644
index 0000000..411748d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unexpected_or_propagate.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unexpected_or_propagate.vv:6:17: error: unexpected `?`, the function `ret_zero` does not return an optional
+    4 |
+    5 | fn opt_fn() ?int {
+    6 |     a := ret_zero()?
+      |                    ^
+    7 |     return a
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unexpected_or_propagate.vv b/v_windows/v/old/vlib/v/checker/tests/unexpected_or_propagate.vv
new file mode 100644
index 0000000..16ef7b0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unexpected_or_propagate.vv
@@ -0,0 +1,12 @@
+fn ret_zero() int {
+	return 0
+}
+
+fn opt_fn() ?int {
+	a := ret_zero()?
+	return a
+}
+
+fn main() {
+	opt_fn() or {}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unfinished_string.out b/v_windows/v/old/vlib/v/checker/tests/unfinished_string.out
new file mode 100644
index 0000000..c42f70a
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unfinished_string.out
@@ -0,0 +1,2 @@
+vlib/v/checker/tests/unfinished_string.vv:2:1: error: unfinished string literal
+    1 | a := '
diff --git a/v_windows/v/old/vlib/v/checker/tests/unfinished_string.vv b/v_windows/v/old/vlib/v/checker/tests/unfinished_string.vv
new file mode 100644
index 0000000..e6374fb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unfinished_string.vv
@@ -0,0 +1 @@
+a := '
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_a.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_a.out
new file mode 100644
index 0000000..225ccd0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_a.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unimplemented_interface_a.vv:10:6: error: `Cat` doesn't implement method `name` of interface `Animal`
+    8 | 
+    9 | fn main() {
+   10 |     foo(Cat{})
+      |         ~~~~~
+   11 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_a.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_a.vv
new file mode 100644
index 0000000..fad1194
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_a.vv
@@ -0,0 +1,11 @@
+interface Animal {
+	name() string
+}
+
+struct Cat {}
+
+fn foo(a Animal) {}
+
+fn main() {
+	foo(Cat{})
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_b.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_b.out
new file mode 100644
index 0000000..edb00d0
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_b.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unimplemented_interface_b.vv:13:6: error: `Cat` incorrectly implements method `name` of interface `Animal`: expected return type `string`
+   11 | fn main() {
+   12 |     c := Cat{}
+   13 |     foo(c)
+      |         ^
+   14 | }
+Details: main.Animal has `name() string`
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_b.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_b.vv
new file mode 100644
index 0000000..0b07a78
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_b.vv
@@ -0,0 +1,14 @@
+interface Animal {
+	name() string
+}
+
+struct Cat {}
+
+fn (c Cat) name() {}
+
+fn foo(a Animal) {}
+
+fn main() {
+	c := Cat{}
+	foo(c)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_c.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_c.out
new file mode 100644
index 0000000..43060d4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_c.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unimplemented_interface_c.vv:12:6: error: `Cat` incorrectly implements method `name` of interface `Animal`: expected 1 parameter(s), not 2
+   10 | 
+   11 | fn main() {
+   12 |     foo(Cat{})
+      |         ~~~~~
+   13 | }
+Details: main.Animal has `name()`
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_c.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_c.vv
new file mode 100644
index 0000000..46960da
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_c.vv
@@ -0,0 +1,13 @@
+interface Animal {
+	name()
+}
+
+struct Cat {}
+
+fn (c Cat) name(s string) {}
+
+fn foo(a Animal) {}
+
+fn main() {
+	foo(Cat{})
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_d.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_d.out
new file mode 100644
index 0000000..5e39c5e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_d.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unimplemented_interface_d.vv:12:6: error: `Cat` incorrectly implements method `speak` of interface `Animal`: expected 2 parameter(s), not 1
+   10 | 
+   11 | fn main() {
+   12 |     foo(Cat{})
+      |         ~~~~~
+   13 | }
+Details: main.Animal has `speak(s string)`
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_d.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_d.vv
new file mode 100644
index 0000000..51b3724
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_d.vv
@@ -0,0 +1,13 @@
+interface Animal {
+	speak(s string)
+}
+
+struct Cat {}
+
+fn (c Cat) speak() {}
+
+fn foo(a Animal) {}
+
+fn main() {
+	foo(Cat{})
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_e.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_e.out
new file mode 100644
index 0000000..f388cb2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_e.out
@@ -0,0 +1,15 @@
+vlib/v/checker/tests/unimplemented_interface_e.vv:12:6: error: `Cat` incorrectly implements method `speak` of interface `Animal`: expected `string`, not `&string` for parameter 1
+   10 | 
+   11 | fn main() {
+   12 |     foo(Cat{})
+      |         ~~~~~
+   13 |     _ = Animal(Cat{})
+   14 | }
+Details: main.Animal has `speak(s string)`
+vlib/v/checker/tests/unimplemented_interface_e.vv:13:6: error: `Cat` incorrectly implements method `speak` of interface `Animal`: expected `string`, not `&string` for parameter 1
+   11 | fn main() {
+   12 |     foo(Cat{})
+   13 |     _ = Animal(Cat{})
+      |         ~~~~~~~~~~~~~
+   14 | }
+Details: main.Animal has `speak(s string)`
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_e.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_e.vv
new file mode 100644
index 0000000..85cee42
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_e.vv
@@ -0,0 +1,14 @@
+interface Animal {
+	speak(s string)
+}
+
+struct Cat {}
+
+fn (c Cat) speak(s &string) {}
+
+fn foo(a Animal) {}
+
+fn main() {
+	foo(Cat{})
+	_ = Animal(Cat{})
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_f.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_f.out
new file mode 100644
index 0000000..3bdc2ac
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_f.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unimplemented_interface_f.vv:11:13: error: `Cat` incorrectly implements method `speak` of interface `Animal`: expected 2 parameter(s), not 1
+    9 | fn main() {
+   10 |     mut animals := []Animal{}
+   11 |     animals << Cat{}
+      |                ~~~~~
+   12 | }
+Details: main.Animal has `speak(s string)`
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_f.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_f.vv
new file mode 100644
index 0000000..3fd767d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_f.vv
@@ -0,0 +1,12 @@
+interface Animal {
+	speak(s string)
+}
+
+struct Cat {}
+
+fn (c Cat) speak() {}
+
+fn main() {
+	mut animals := []Animal{}
+	animals << Cat{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_g.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_g.out
new file mode 100644
index 0000000..61c2cd3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_g.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unimplemented_interface_g.vv:12:13: error: `Cat` incorrectly implements method `speak` of interface `Animal`, expected `speak(s string)`
+   10 |     mut animals := []Animal{}
+   11 |     mut cats := []Cat{}
+   12 |     animals << cats
+      |                ~~~~
+   13 | }
+   14 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_g.vv.disabled b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_g.vv.disabled
new file mode 100644
index 0000000..fca4beb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_g.vv.disabled
@@ -0,0 +1,14 @@
+interface Animal {
+	speak(s string)
+}
+
+struct Cat {}
+
+fn (c Cat) speak() {}
+
+fn main() {
+	mut animals := []Animal{}
+	mut cats := []Cat{}
+	animals << cats
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_h.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_h.out
new file mode 100644
index 0000000..0731050
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_h.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unimplemented_interface_h.vv:9:13: error: `Cat` doesn't implement field `name` of interface `Animal`
+    7 | fn main() {
+    8 |     mut animals := []Animal{}
+    9 |     animals << Cat{}
+      |                ~~~~~
+   10 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_h.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_h.vv
new file mode 100644
index 0000000..cd00881
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_h.vv
@@ -0,0 +1,10 @@
+interface Animal {
+	name string
+}
+
+struct Cat {}
+
+fn main() {
+	mut animals := []Animal{}
+	animals << Cat{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_i.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_i.out
new file mode 100644
index 0000000..073e248
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_i.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unimplemented_interface_i.vv:11:13: error: `Cat` incorrectly implements field `name` of interface `Animal`, expected `string`, got `int`
+    9 | fn main() {
+   10 |     mut animals := []Animal{}
+   11 |     animals << Cat{}
+      |                ~~~~~
+   12 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_i.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_i.vv
new file mode 100644
index 0000000..4c50f0e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_i.vv
@@ -0,0 +1,12 @@
+interface Animal {
+	name string
+}
+
+struct Cat {
+	name int
+}
+
+fn main() {
+	mut animals := []Animal{}
+	animals << Cat{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_j.out b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_j.out
new file mode 100644
index 0000000..4c85238
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_j.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unimplemented_interface_j.vv:12:13: error: `Cat` incorrectly implements interface `Animal`, field `name` must be mutable
+   10 | fn main() {
+   11 |     mut animals := []Animal{}
+   12 |     animals << Cat{}
+      |                ~~~~~
+   13 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_j.vv b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_j.vv
new file mode 100644
index 0000000..f54dab3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unimplemented_interface_j.vv
@@ -0,0 +1,13 @@
+interface Animal {
+mut:
+	name string
+}
+
+struct Cat {
+	name string
+}
+
+fn main() {
+	mut animals := []Animal{}
+	animals << Cat{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/union_unsafe_fields.out b/v_windows/v/old/vlib/v/checker/tests/union_unsafe_fields.out
new file mode 100644
index 0000000..be40d1b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/union_unsafe_fields.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/union_unsafe_fields.vv:10:9: error: reading a union field (or its address) requires `unsafe`
+    8 |     mut u := Uf32{u: 3}
+    9 |     u.f = 3.3 // ok
+   10 |     _ := u.u
+      |            ^
+   11 |     return &u.f
+   12 | }
+vlib/v/checker/tests/union_unsafe_fields.vv:11:12: error: reading a union field (or its address) requires `unsafe`
+    9 |     u.f = 3.3 // ok
+   10 |     _ := u.u
+   11 |     return &u.f
+      |               ^
+   12 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/union_unsafe_fields.vv b/v_windows/v/old/vlib/v/checker/tests/union_unsafe_fields.vv
new file mode 100644
index 0000000..6a1bc0f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/union_unsafe_fields.vv
@@ -0,0 +1,12 @@
+union Uf32 {
+mut:
+	f f32
+	u u32
+}
+
+fn f() f32 {
+	mut u := Uf32{u: 3}
+	u.f = 3.3 // ok
+	_ := u.u
+	return &u.f
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_array_element_type_b.out b/v_windows/v/old/vlib/v/checker/tests/unknown_array_element_type_b.out
new file mode 100644
index 0000000..2efc456
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_array_element_type_b.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unknown_array_element_type_b.vv:2:6: error: unknown type `abc`.
+Did you mean `Aaa`?
+    1 | struct Aaa {
+    2 |     a []abc
+      |         ~~~
+    3 | }
+    4 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_array_element_type_b.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_array_element_type_b.vv
new file mode 100644
index 0000000..0fc059f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_array_element_type_b.vv
@@ -0,0 +1,9 @@
+struct Aaa {
+	a []abc
+}
+
+fn main() {
+	s := Aaa{}
+	println(s)
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_as_type.out b/v_windows/v/old/vlib/v/checker/tests/unknown_as_type.out
new file mode 100644
index 0000000..e520655
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_as_type.out
@@ -0,0 +1,8 @@
+vlib/v/checker/tests/unknown_as_type.vv:7:9: error: unknown type `Stringg`.
+Did you mean `String`?
+    5 |
+    6 | fn foo(e Expr) {
+    7 |     x := e as Stringg
+      |            ~~
+    8 |     println(x)
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_as_type.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_as_type.vv
new file mode 100644
index 0000000..66c2a57
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_as_type.vv
@@ -0,0 +1,13 @@
+type Expr = Int | String
+
+struct Int {}
+struct String {}
+
+fn foo(e Expr) {
+	x := e as Stringg
+	println(x)
+}
+
+fn main() {
+
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_comptime_expr.out b/v_windows/v/old/vlib/v/checker/tests/unknown_comptime_expr.out
new file mode 100644
index 0000000..b97e13d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_comptime_expr.out
@@ -0,0 +1,42 @@
+vlib/v/checker/tests/unknown_comptime_expr.vv:5:6: error: `foo` is mut and may have changed since its definition
+    3 | fn main() {
+    4 |     mut foo := 0
+    5 |     $if foo == 0 {}
+      |         ~~~
+    6 | 
+    7 |     bar := unknown_at_ct()
+vlib/v/checker/tests/unknown_comptime_expr.vv:8:6: error: definition of `bar` is unknown at compile time
+    6 | 
+    7 |     bar := unknown_at_ct()
+    8 |     $if bar == 0 {}
+      |         ~~~
+    9 | }
+   10 |
+vlib/v/checker/tests/unknown_comptime_expr.vv:13:6: error: undefined ident: `huh`
+   11 | fn if_is() {
+   12 |     s := S1{}
+   13 |     $if huh.typ is T {}
+      |         ~~~
+   14 |     $if s is int {}
+   15 |     $if s.i is 5 {}
+vlib/v/checker/tests/unknown_comptime_expr.vv:14:6: error: invalid `$if` condition: expected a type or a selector expression or an interface check
+   12 |     s := S1{}
+   13 |     $if huh.typ is T {}
+   14 |     $if s is int {}
+      |         ^
+   15 |     $if s.i is 5 {}
+   16 |     $if s.i is T {}
+vlib/v/checker/tests/unknown_comptime_expr.vv:15:13: error: invalid `$if` condition: expected a type
+   13 |     $if huh.typ is T {}
+   14 |     $if s is int {}
+   15 |     $if s.i is 5 {}
+      |                ^
+   16 |     $if s.i is T {}
+   17 | }
+vlib/v/checker/tests/unknown_comptime_expr.vv:16:13: error: unknown type `T`
+   14 |     $if s is int {}
+   15 |     $if s.i is 5 {}
+   16 |     $if s.i is T {}
+      |                ^
+   17 | }
+   18 |
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_comptime_expr.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_comptime_expr.vv
new file mode 100644
index 0000000..c3734ae
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_comptime_expr.vv
@@ -0,0 +1,22 @@
+fn unknown_at_ct() int { return 0 }
+
+fn main() {
+	mut foo := 0
+	$if foo == 0 {}
+
+	bar := unknown_at_ct()
+	$if bar == 0 {}
+}
+
+fn if_is() {
+	s := S1{}
+	$if huh.typ is T {}
+	$if s is int {}
+	$if s.i is 5 {}
+	$if s.i is T {}
+}
+
+struct S1 {
+	i int
+}
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_field.out b/v_windows/v/old/vlib/v/checker/tests/unknown_field.out
new file mode 100644
index 0000000..395eedf
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_field.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unknown_field.vv:7:12: error: type `Test` has no field named `sdd`
+    5 | fn main() {
+    6 |     t := Test{}
+    7 |     println(t.sdd)
+      |               ~~~
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_field.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_field.vv
new file mode 100644
index 0000000..8cf14a9
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_field.vv
@@ -0,0 +1,8 @@
+module main
+
+struct Test {}
+
+fn main() {
+	t := Test{}
+	println(t.sdd)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_generic_type.out b/v_windows/v/old/vlib/v/checker/tests/unknown_generic_type.out
new file mode 100644
index 0000000..ea09b5e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_generic_type.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unknown_generic_type.vv:6:13: error: unknown type `Foo`
+    4 |
+    5 | fn main() {
+    6 |     x := decode<Foo>('{"name": "test"}')?
+      |                ~~~~~
+    7 |     println(x)
+    8 | }
\ No newline at end of file
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_generic_type.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_generic_type.vv
new file mode 100644
index 0000000..1b88eb2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_generic_type.vv
@@ -0,0 +1,8 @@
+fn decode<T>(raw_data string) ?T {
+	return none
+}
+
+fn main() {
+	x := decode<Foo>('{"name": "test"}')?
+	println(x)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_method.out b/v_windows/v/old/vlib/v/checker/tests/unknown_method.out
new file mode 100644
index 0000000..037d2f3
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_method.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unknown_method.vv:7:12: error: unknown method or field: `Test.sdd`
+    5 | fn main() {
+    6 |     t := Test{}
+    7 |     println(t.sdd())
+      |               ~~~~~
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_method.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_method.vv
new file mode 100644
index 0000000..879b372
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_method.vv
@@ -0,0 +1,8 @@
+module main
+
+struct Test {}
+
+fn main() {
+	t := Test{}
+	println(t.sdd())
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_method_suggest_name.out b/v_windows/v/old/vlib/v/checker/tests/unknown_method_suggest_name.out
new file mode 100644
index 0000000..f80de09
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_method_suggest_name.out
@@ -0,0 +1,22 @@
+vlib/v/checker/tests/unknown_method_suggest_name.vv:13:12: error: unknown type `hash.crc32.Crc33`.
+Did you mean `crc32.Crc32`?
+   11 |     y int
+   12 |     z int
+   13 |     ccc crc32.Crc33
+      |               ~~~~~
+   14 | }
+   15 |
+vlib/v/checker/tests/unknown_method_suggest_name.vv:27:9: error: unknown method or field: `Point.tranzlate`.
+Did you mean `translate`?
+   25 |     p := Point{1, 2, 3}
+   26 |     v := Vector{x: 5, y: 5, z: 10}
+   27 |     z := p.tranzlate(v)
+      |            ~~~~~~~~~~~~
+   28 |     println('p: $p')
+   29 |     println('v: $v')
+vlib/v/checker/tests/unknown_method_suggest_name.vv:30:15: error: expression does not return a value
+   28 |     println('p: $p')
+   29 |     println('v: $v')
+   30 |     println('z: $z')
+      |                  ^
+   31 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_method_suggest_name.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_method_suggest_name.vv
new file mode 100644
index 0000000..52af44c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_method_suggest_name.vv
@@ -0,0 +1,31 @@
+import hash.crc32
+
+struct Point {
+	x   int
+	y   int
+	z   int
+}
+
+struct Vector {
+	x int
+	y int
+	z int
+	ccc crc32.Crc33
+}
+
+fn (p Point) translate(v Vector) Point {
+	return Point{p.x + v.x, p.y + v.y, p.z + v.z}
+}
+
+fn (p Point) identity() Point {
+	return Point{1, 1, 1}
+}
+
+fn main() {
+	p := Point{1, 2, 3}
+	v := Vector{x: 5, y: 5, z: 10}
+	z := p.tranzlate(v)
+	println('p: $p')
+	println('v: $v')
+	println('z: $z')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_a.out b/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_a.out
new file mode 100644
index 0000000..5c6e6cb
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_a.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unknown_sizeof_type_err_a.vv:14:34: cgen error: unknown type `T`
+   12 |     println("size of Abc: ${sizeof(Abc)}")
+   13 |     println("size of Xyz: ${sizeof(Xyz)}")
+   14 |     println("size of Test: ${sizeof(T)}")
+      |                                     ^
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_a.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_a.vv
new file mode 100644
index 0000000..dd15843
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_a.vv
@@ -0,0 +1,15 @@
+struct Abc {
+	i int
+}
+
+struct Xyz {
+	f f64
+}
+
+type Test = Abc | Xyz
+
+fn main() {
+	println("size of Abc: ${sizeof(Abc)}")
+	println("size of Xyz: ${sizeof(Xyz)}")
+	println("size of Test: ${sizeof(T)}")
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_b.out b/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_b.out
new file mode 100644
index 0000000..7daa009
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_b.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unknown_sizeof_type_err_b.vv:14:34: cgen error: unknown type `Zabc`
+   12 |     println("size of Abc: ${sizeof(Abc)}")
+   13 |     println("size of Xyz: ${sizeof(Xyz)}")
+   14 |     println("size of Test: ${sizeof(Zabc)}")
+      |                                     ~~~~
+   15 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_b.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_b.vv
new file mode 100644
index 0000000..154f406
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_sizeof_type_err_b.vv
@@ -0,0 +1,15 @@
+struct Abc {
+	i int
+}
+
+struct Xyz {
+	f f64
+}
+
+type Test = Abc | Xyz
+
+fn main() {
+	println("size of Abc: ${sizeof(Abc)}")
+	println("size of Xyz: ${sizeof(Xyz)}")
+	println("size of Test: ${sizeof(Zabc)}")
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_struct_field_suggest_name.out b/v_windows/v/old/vlib/v/checker/tests/unknown_struct_field_suggest_name.out
new file mode 100644
index 0000000..98347d6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_struct_field_suggest_name.out
@@ -0,0 +1,15 @@
+vlib/v/checker/tests/unknown_struct_field_suggest_name.vv:11:16: error: type `Points` has no field named `xxxa`.
+Did you mean `xxxx`?
+    9 |     p := Points{[1], [2], [3]}
+   10 |     println('p: $p')
+   11 |     for x in p.xxxa {
+      |                ~~~~
+   12 |         println('x: $x')
+   13 |     }
+vlib/v/checker/tests/unknown_struct_field_suggest_name.vv:12:19: error: expression does not return a value
+   10 |     println('p: $p')
+   11 |     for x in p.xxxa {
+   12 |         println('x: $x')
+      |                      ^
+   13 |     }
+   14 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_struct_field_suggest_name.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_struct_field_suggest_name.vv
new file mode 100644
index 0000000..aebdcea
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_struct_field_suggest_name.vv
@@ -0,0 +1,14 @@
+
+struct Points {
+	xxxx   []int
+	yyyy   []int
+	zzzz   []int
+}
+
+fn main() {
+	p := Points{[1], [2], [3]}
+	println('p: $p')
+    for x in p.xxxa {
+    	println('x: $x')
+    }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_struct_name.out b/v_windows/v/old/vlib/v/checker/tests/unknown_struct_name.out
new file mode 100644
index 0000000..d21f02d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_struct_name.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unknown_struct_name.vv:4:7: error: unknown struct `F`
+    2 |
+    3 | fn main() {
+    4 |     _ := F{}
+      |          ~~~
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_struct_name.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_struct_name.vv
new file mode 100644
index 0000000..52a4330
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_struct_name.vv
@@ -0,0 +1,5 @@
+module main
+
+fn main() {
+	_ := F{}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_var_assign.out b/v_windows/v/old/vlib/v/checker/tests/unknown_var_assign.out
new file mode 100644
index 0000000..6a12a8c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_var_assign.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/unknown_var_assign.vv:2:5: error: undefined ident: `x` (use `:=` to declare a variable)
+    1 | fn main() {
+    2 |     x = 'hello v'
+      |     ^
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unknown_var_assign.vv b/v_windows/v/old/vlib/v/checker/tests/unknown_var_assign.vv
new file mode 100644
index 0000000..d7ed530
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unknown_var_assign.vv
@@ -0,0 +1,3 @@
+fn main() {
+    x = 'hello v'
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unnecessary_parenthesis.out b/v_windows/v/old/vlib/v/checker/tests/unnecessary_parenthesis.out
new file mode 100644
index 0000000..eee14f7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unnecessary_parenthesis.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/unnecessary_parenthesis.vv:2:2: error: unnecessary `()` in `if` condition, use `if expr {` instead of `if (expr) {`.
+    1 | fn main() {
+    2 |     if (1 == 1) {
+      |     ~~~~~~~~~~~
+    3 |         println('yeay')
+    4 |     } else if (1 == 2) {
+vlib/v/checker/tests/unnecessary_parenthesis.vv:4:4: error: unnecessary `()` in `if` condition, use `if expr {` instead of `if (expr) {`.
+    2 |     if (1 == 1) {
+    3 |         println('yeay')
+    4 |     } else if (1 == 2) {
+      |       ~~~~~~~~~~~~~~~~
+    5 |         println("oh no :'(")
+    6 |     } else if (1 == 3) {
+vlib/v/checker/tests/unnecessary_parenthesis.vv:6:4: error: unnecessary `()` in `if` condition, use `if expr {` instead of `if (expr) {`.
+    4 |     } else if (1 == 2) {
+    5 |         println("oh no :'(")
+    6 |     } else if (1 == 3) {
+      |       ~~~~~~~~~~~~~~~~
+    7 |         println("what's wrong with physics ????")
+    8 |     }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unnecessary_parenthesis.vv b/v_windows/v/old/vlib/v/checker/tests/unnecessary_parenthesis.vv
new file mode 100644
index 0000000..c1eb1ae
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unnecessary_parenthesis.vv
@@ -0,0 +1,9 @@
+fn main() {
+	if (1 == 1) {
+		println('yeay')
+	} else if (1 == 2) {
+		println("oh no :'(")
+	} else if (1 == 3) {
+		println("what's wrong with physics ????")
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unreachable_code.out b/v_windows/v/old/vlib/v/checker/tests/unreachable_code.out
new file mode 100644
index 0000000..ae0dc92
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unreachable_code.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unreachable_code.vv:3:4: error: unreachable code
+    1 | fn foo() int {
+    2 |     return if 1 == 1 { 1 } else { 2 }
+    3 |     a := 1
+      |       ~~
+    4 |     println(a)
+    5 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unreachable_code.vv b/v_windows/v/old/vlib/v/checker/tests/unreachable_code.vv
new file mode 100644
index 0000000..7da480f
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unreachable_code.vv
@@ -0,0 +1,8 @@
+fn foo() int {
+	return if 1 == 1 { 1 } else { 2 }
+	a := 1
+	println(a)
+}
+fn main() {
+	foo()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unsafe_c_calls_should_be_checked.out b/v_windows/v/old/vlib/v/checker/tests/unsafe_c_calls_should_be_checked.out
new file mode 100644
index 0000000..3d791c4
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unsafe_c_calls_should_be_checked.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/unsafe_c_calls_should_be_checked.vv:3:16: error: function `C.malloc` must be called from an `unsafe` block
+    1 |
+    2 | fn test_c() {
+    3 |     mut p := C.malloc(4)
+      |                ~~~~~~~~~
+    4 |     s := 'hope'
+    5 |     C.memcpy(p, s.str, 4)
+vlib/v/checker/tests/unsafe_c_calls_should_be_checked.vv:5:7: error: function `C.memcpy` must be called from an `unsafe` block
+    3 |     mut p := C.malloc(4)
+    4 |     s := 'hope'
+    5 |     C.memcpy(p, s.str, 4)
+      |       ~~~~~~~~~~~~~~~~~~~
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unsafe_c_calls_should_be_checked.vv b/v_windows/v/old/vlib/v/checker/tests/unsafe_c_calls_should_be_checked.vv
new file mode 100644
index 0000000..092fe2c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unsafe_c_calls_should_be_checked.vv
@@ -0,0 +1,6 @@
+
+fn test_c() {
+    mut p := C.malloc(4)
+    s := 'hope'
+    C.memcpy(p, s.str, 4)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unsafe_fixed_array_assign.out b/v_windows/v/old/vlib/v/checker/tests/unsafe_fixed_array_assign.out
new file mode 100644
index 0000000..fae8c95
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unsafe_fixed_array_assign.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/unsafe_fixed_array_assign.vv:8:7: error: assignment from one fixed array to another with a pointer element type is prohibited outside of `unsafe`
+    6 | mut box := Box { num: 10 }
+    7 | a := [&box]!
+    8 | mut b := a
+      |       ~~
+    9 | b[0].num = 0
+   10 | println(a)
diff --git a/v_windows/v/old/vlib/v/checker/tests/unsafe_fixed_array_assign.vv b/v_windows/v/old/vlib/v/checker/tests/unsafe_fixed_array_assign.vv
new file mode 100644
index 0000000..38defbd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unsafe_fixed_array_assign.vv
@@ -0,0 +1,10 @@
+struct Box {
+mut:
+	num int
+}
+
+mut box := Box { num: 10 }
+a := [&box]!
+mut b := a
+b[0].num = 0
+println(a)
diff --git a/v_windows/v/old/vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.out b/v_windows/v/old/vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.out
new file mode 100644
index 0000000..9ac0225
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.out
@@ -0,0 +1,28 @@
+vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.vv:4:6: error: pointer arithmetic is only allowed in `unsafe` blocks
+    2 |     mut v := 5
+    3 |     mut p := &v
+    4 |     p++
+      |      ~~
+    5 |     p += 2
+    6 |     _ := v
+vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.vv:5:7: error: pointer arithmetic is only allowed in `unsafe` blocks
+    3 |     mut p := &v
+    4 |     p++
+    5 |     p += 2
+      |       ~~
+    6 |     _ := v
+    7 | }
+vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.vv:11:14: error: pointer arithmetic is only allowed in `unsafe` blocks
+    9 | fn test_ptr_infix() {
+   10 |     v := 4
+   11 |     mut q := &v - 1
+      |              ~~~~~~
+   12 |     q = q + 3
+   13 |     _ := q
+vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.vv:12:9: error: pointer arithmetic is only allowed in `unsafe` blocks
+   10 |     v := 4
+   11 |     mut q := &v - 1
+   12 |     q = q + 3
+      |         ~~~~~
+   13 |     _ := q
+   14 |     _ := v
diff --git a/v_windows/v/old/vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.vv b/v_windows/v/old/vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.vv
new file mode 100644
index 0000000..b83630b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unsafe_pointer_arithmetic_should_be_checked.vv
@@ -0,0 +1,15 @@
+fn test_ptr_assign() {
+    mut v := 5
+    mut p := &v
+    p++
+    p += 2
+    _ := v
+}
+
+fn test_ptr_infix() {
+    v := 4
+    mut q := &v - 1
+    q = q + 3
+    _ := q
+    _ := v
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unsafe_required.out b/v_windows/v/old/vlib/v/checker/tests/unsafe_required.out
new file mode 100644
index 0000000..463a6a2
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unsafe_required.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/unsafe_required.vv:8:7: error: method `S1.f` must be called from an `unsafe` block
+    6 | fn test_funcs() {
+    7 |     s := S1{}
+    8 |     s.f()
+      |       ~~~
+    9 | }
+   10 |
+vlib/v/checker/tests/unsafe_required.vv:16:7: error: pointer indexing is only allowed in `unsafe` blocks
+   14 |     _ = b[0] // OK
+   15 |     c := &b
+   16 |     _ = c[0]
+      |          ~~~
+   17 | 
+   18 |     v := 4
+vlib/v/checker/tests/unsafe_required.vv:20:10: error: pointer indexing is only allowed in `unsafe` blocks
+   18 |     v := 4
+   19 |     p := &v
+   20 |     _ = p[0]
+      |          ~~~
+   21 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/unsafe_required.vv b/v_windows/v/old/vlib/v/checker/tests/unsafe_required.vv
new file mode 100644
index 0000000..e47a90e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unsafe_required.vv
@@ -0,0 +1,21 @@
+struct S1 {}
+
+[unsafe]
+fn (s S1) f(){}
+
+fn test_funcs() {
+    s := S1{}
+    s.f()
+}
+
+fn test_ptr_index(mut a []string) {
+	_ = a[0] // OK
+	b := ['jo']
+	_ = b[0] // OK
+	c := &b
+	_ = c[0]
+
+    v := 4
+    p := &v
+    _ = p[0]
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/unwrapped_optional_infix.out b/v_windows/v/old/vlib/v/checker/tests/unwrapped_optional_infix.out
new file mode 100644
index 0000000..146e7e6
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unwrapped_optional_infix.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/unwrapped_optional_infix.vv:5:9: error: unwrapped optional cannot be used in an infix expression
+    3 | }
+    4 | 
+    5 | println(test() == "")
+      |         ~~~~~~~~~~~~
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/unwrapped_optional_infix.vv b/v_windows/v/old/vlib/v/checker/tests/unwrapped_optional_infix.vv
new file mode 100644
index 0000000..432b0cc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/unwrapped_optional_infix.vv
@@ -0,0 +1,5 @@
+fn test() ?string {
+	return ""
+}
+
+println(test() == "")
diff --git a/v_windows/v/old/vlib/v/checker/tests/use_deprecated_function_warning.out b/v_windows/v/old/vlib/v/checker/tests/use_deprecated_function_warning.out
new file mode 100644
index 0000000..9cffcba
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/use_deprecated_function_warning.out
@@ -0,0 +1,20 @@
+vlib/v/checker/tests/use_deprecated_function_warning.vv:12:2: error: function `xyz` has been deprecated
+   10 | 
+   11 | fn main() {
+   12 |     xyz()
+      |     ~~~~~
+   13 |     abc()
+   14 | }
+vlib/v/checker/tests/use_deprecated_function_warning.vv:13:2: error: function `abc` has been deprecated; use foo2 instead
+   11 | fn main() {
+   12 |     xyz()
+   13 |     abc()
+      |     ~~~~~
+   14 | }
+   15 |
+vlib/v/checker/tests/use_deprecated_function_warning.vv:23:4: error: method `S1.m` has been deprecated; use bar instead
+   21 | fn method() {
+   22 |     s := S1{}
+   23 |     s.m()
+      |       ~~~
+   24 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/use_deprecated_function_warning.vv b/v_windows/v/old/vlib/v/checker/tests/use_deprecated_function_warning.vv
new file mode 100644
index 0000000..d5f95ef
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/use_deprecated_function_warning.vv
@@ -0,0 +1,24 @@
+[deprecated]
+fn xyz() {
+	println('hi')
+}
+
+[deprecated: 'use foo2 instead']
+fn abc() {
+	println('hi')
+}
+
+fn main() {
+	xyz()
+	abc()
+}
+
+struct S1 {}
+
+[deprecated: 'use bar instead']
+fn (s S1) m() {}
+
+fn method() {
+	s := S1{}
+	s.m()
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/var_duplicate_const.out b/v_windows/v/old/vlib/v/checker/tests/var_duplicate_const.out
new file mode 100644
index 0000000..b7b4633
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/var_duplicate_const.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/var_duplicate_const.vv:4:5: error: duplicate of a const name `size`
+    2 |
+    3 | fn main() {
+    4 |     size := 11
+      |     ~~~~
+    5 |     println(main.size)
+    6 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/var_duplicate_const.vv b/v_windows/v/old/vlib/v/checker/tests/var_duplicate_const.vv
new file mode 100644
index 0000000..4275e7b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/var_duplicate_const.vv
@@ -0,0 +1,6 @@
+const size = 22
+
+fn main() {
+    size := 11
+    println(main.size)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used.out b/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used.out
new file mode 100644
index 0000000..2cb3593
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/var_eval_not_used.vv:6:2: error: `c` evaluated but not used 
+    4 | 
+    5 | fn main() {
+    6 |     c
+      |     ^
+    7 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used.vv b/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used.vv
new file mode 100644
index 0000000..57642a1
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used.vv
@@ -0,0 +1,7 @@
+const (
+	c = 1
+)
+
+fn main() {
+	c
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used_scope.out b/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used_scope.out
new file mode 100644
index 0000000..89c4afd
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used_scope.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/var_eval_not_used_scope.vv:7:3: error: `c` evaluated but not used 
+    5 | fn main() {
+    6 |     {
+    7 |         c
+      |         ^
+    8 |     }
+    9 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used_scope.vv b/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used_scope.vv
new file mode 100644
index 0000000..298e35b
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/var_eval_not_used_scope.vv
@@ -0,0 +1,9 @@
+const (
+	c = 1
+)
+
+fn main() {
+	{
+		c
+	}
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/var_used_before_declaration.out b/v_windows/v/old/vlib/v/checker/tests/var_used_before_declaration.out
new file mode 100644
index 0000000..b3ea361
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/var_used_before_declaration.out
@@ -0,0 +1,6 @@
+vlib/v/checker/tests/var_used_before_declaration.vv:2:13: error: undefined variable `x` (used before declaration)
+    1 | fn main() {
+    2 |     println(x)
+      |             ^
+    3 |     x := 'hello v'
+    4 |    _ = x
diff --git a/v_windows/v/old/vlib/v/checker/tests/var_used_before_declaration.vv b/v_windows/v/old/vlib/v/checker/tests/var_used_before_declaration.vv
new file mode 100644
index 0000000..1a2b63d
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/var_used_before_declaration.vv
@@ -0,0 +1,5 @@
+fn main() {
+    println(x)
+    x := 'hello v'
+   _ = x
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/void_fn_as_value.out b/v_windows/v/old/vlib/v/checker/tests/void_fn_as_value.out
new file mode 100644
index 0000000..9898c19
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/void_fn_as_value.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/void_fn_as_value.vv:5:7: error: unknown function: x
+    3 | fn main() {
+    4 |     mut a := 'aa'
+    5 |     a += x('a','b')
+      |          ~~~~~~~~~~
+    6 |     mut b := 'abcdef'
+    7 |     _ = b
diff --git a/v_windows/v/old/vlib/v/checker/tests/void_fn_as_value.vv b/v_windows/v/old/vlib/v/checker/tests/void_fn_as_value.vv
new file mode 100644
index 0000000..012019e
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/void_fn_as_value.vv
@@ -0,0 +1,9 @@
+module main
+
+fn main() {
+	mut a := 'aa'
+	a += x('a','b')
+	mut b := 'abcdef'
+	_ = b
+	_ = a
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/void_function_assign_to_string.out b/v_windows/v/old/vlib/v/checker/tests/void_function_assign_to_string.out
new file mode 100644
index 0000000..b04d39c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/void_function_assign_to_string.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/void_function_assign_to_string.vv:6:4: error: assignment mismatch: 1 variable(s) but `x()` returns 0 value(s)
+    4 | fn main(){
+    5 |     mut a := ''
+    6 |     a = x(1,2) // hello
+      |       ^
+    7 |     eprintln('a: $a')
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/void_function_assign_to_string.vv b/v_windows/v/old/vlib/v/checker/tests/void_function_assign_to_string.vv
new file mode 100644
index 0000000..fddd5fc
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/void_function_assign_to_string.vv
@@ -0,0 +1,8 @@
+fn x(x int,y int) {
+
+}
+fn main(){
+	mut a := ''
+	a = x(1,2) // hello
+	eprintln('a: $a')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/void_optional_err.out b/v_windows/v/old/vlib/v/checker/tests/void_optional_err.out
new file mode 100644
index 0000000..c9efcb7
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/void_optional_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/void_optional_err.vv:1:16: error: use `?` instead of `?void`
+    1 | fn ret_void() ?void {
+      |                ~~~~
+    2 |     return error('error')
+    3 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/void_optional_err.vv b/v_windows/v/old/vlib/v/checker/tests/void_optional_err.vv
new file mode 100644
index 0000000..136e6e5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/void_optional_err.vv
@@ -0,0 +1,7 @@
+fn ret_void() ?void {
+	return error('error')
+}
+
+fn main() {
+	_ = ret_void() or { panic('$err') }
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/vweb_routing_checks.out b/v_windows/v/old/vlib/v/checker/tests/vweb_routing_checks.out
new file mode 100644
index 0000000..141d7b5
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/vweb_routing_checks.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/vweb_routing_checks.vv:20:1: error: mismatched parameters count between vweb method `App.bar` (1) and route attribute ['/bar'] (0)
+   18 | // segfault because path taks 0 vars and fcn takes 1 arg
+   19 | ['/bar']
+   20 | pub fn (mut app App) bar(a string) vweb.Result {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   21 |     return app.html('works')
+   22 | }
+vlib/v/checker/tests/vweb_routing_checks.vv:26:1: error: mismatched parameters count between vweb method `App.cow` (0) and route attribute ['/cow/:low'] (1)
+   24 | // no segfault, but it shouldnt compile
+   25 | ['/cow/:low']
+   26 | pub fn (mut app App) cow() vweb.Result {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   27 |     return app.html('works')
+   28 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/vweb_routing_checks.vv b/v_windows/v/old/vlib/v/checker/tests/vweb_routing_checks.vv
new file mode 100644
index 0000000..53f1d09
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/vweb_routing_checks.vv
@@ -0,0 +1,47 @@
+import vweb
+
+struct App {
+	vweb.Context
+}
+
+pub fn (mut app App) no_attributes(a string) vweb.Result {
+	return app.text('ok')
+}
+
+// works fine, as long as fcn gets 1 arg and route takes 1 var
+['/foo/:bar']
+pub fn (mut app App) foo(a string) vweb.Result {
+	eprintln('foo')
+	return app.html('works')
+}
+
+// segfault because path taks 0 vars and fcn takes 1 arg
+['/bar']
+pub fn (mut app App) bar(a string) vweb.Result {
+	return app.html('works')
+}
+
+// no segfault, but it shouldnt compile
+['/cow/:low']
+pub fn (mut app App) cow() vweb.Result {
+	return app.html('works')
+}
+
+/*
+pub fn (app App) init_server() {
+	//
+}
+
+pub fn (app App) before_request() {
+	//
+}
+*/
+
+pub fn (mut app App) index() {
+	app.html('hello')
+}
+
+fn main() {
+	port := 8181
+	vweb.run<App>(&App{}, port)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/vweb_tmpl_used_var.out b/v_windows/v/old/vlib/v/checker/tests/vweb_tmpl_used_var.out
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/vweb_tmpl_used_var.out
@@ -0,0 +1 @@
+
diff --git a/v_windows/v/old/vlib/v/checker/tests/vweb_tmpl_used_var.vv b/v_windows/v/old/vlib/v/checker/tests/vweb_tmpl_used_var.vv
new file mode 100644
index 0000000..13cdbec
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/vweb_tmpl_used_var.vv
@@ -0,0 +1,14 @@
+import vweb
+
+struct App {
+	vweb.Context
+}
+
+pub fn (mut app App) index() vweb.Result {
+    test := 'test'
+    return $vweb.html()
+}
+
+fn main() {
+	vweb.run<App>(&App{}, 8181)
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/warnings_for_string_c2v_calls.out b/v_windows/v/old/vlib/v/checker/tests/warnings_for_string_c2v_calls.out
new file mode 100644
index 0000000..f570847
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/warnings_for_string_c2v_calls.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/warnings_for_string_c2v_calls.vv:8:7: error: to convert a C string buffer pointer to a V string, use x.vstring() instead of string(x)
+    6 |         p[2] = `z`
+    7 |     }
+    8 |     x := string(p)
+      |          ~~~~~~~~~
+    9 |     eprintln('x: $x')
+   10 |     eprintln('x.len: $x.len')
diff --git a/v_windows/v/old/vlib/v/checker/tests/warnings_for_string_c2v_calls.vv b/v_windows/v/old/vlib/v/checker/tests/warnings_for_string_c2v_calls.vv
new file mode 100644
index 0000000..7f4dade
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/warnings_for_string_c2v_calls.vv
@@ -0,0 +1,11 @@
+fn main() {
+	mut p := vcalloc(20)
+	unsafe {
+		p[0] = `A`
+		p[1] = `B`
+		p[2] = `z`
+	}
+	x := string(p)
+	eprintln('x: $x')
+	eprintln('x.len: $x.len')
+}
diff --git a/v_windows/v/old/vlib/v/checker/tests/wrong_propagate_ret_type.out b/v_windows/v/old/vlib/v/checker/tests/wrong_propagate_ret_type.out
new file mode 100644
index 0000000..af8d737
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/wrong_propagate_ret_type.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/wrong_propagate_ret_type.vv:6:17: error: to propagate the optional call, `opt_call` must return an optional
+    4 |
+    5 | fn opt_call() int {
+    6 |     a := ret_none()?
+      |                    ^
+    7 |     return a
+    8 | }
diff --git a/v_windows/v/old/vlib/v/checker/tests/wrong_propagate_ret_type.vv b/v_windows/v/old/vlib/v/checker/tests/wrong_propagate_ret_type.vv
new file mode 100644
index 0000000..82ef06c
--- /dev/null
+++ b/v_windows/v/old/vlib/v/checker/tests/wrong_propagate_ret_type.vv
@@ -0,0 +1,8 @@
+fn ret_none() ?int {
+	return none
+}
+
+fn opt_call() int {
+	a := ret_none()?
+	return a
+}