1 files changed, 261 insertions, 0 deletions
diff --git a/v_windows/v/old/vlib/strconv/atoi.v b/v_windows/v/old/vlib/strconv/atoi.v
new file mode 100644
index 0000000..3334919
--- /dev/null
+++ b/v_windows/v/old/vlib/strconv/atoi.v
@@ -0,0 +1,261 @@
+module strconv
+
+// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+// TODO: use optionals, or some way to return default with error.
+const (
+	// int_size is the size in bits of an int or uint value.
+	// int_size = 32 << (~u32(0) >> 63)
+	// max_u64 = u64(u64(1 << 63) - 1)
+	int_size = 32
+	max_u64  = u64(18446744073709551615) // as u64 // use this until we add support
+)
+
+pub fn byte_to_lower(c byte) byte {
+	return c | (`x` - `X`)
+}
+
+// common_parse_uint is called by parse_uint and allows the parsing
+// to stop on non or invalid digit characters and return with an error
+pub fn common_parse_uint(s string, _base int, _bit_size int, error_on_non_digit bool, error_on_high_digit bool) ?u64 {
+	result, err := common_parse_uint2(s, _base, _bit_size)
+	// TODO: error_on_non_digit and error_on_high_digit have no difference
+	if err != 0 && (error_on_non_digit || error_on_high_digit) {
+		match err {
+			-1 { return error('common_parse_uint: wrong base $_base for $s') }
+			-2 { return error('common_parse_uint: wrong bit size $_bit_size for $s') }
+			-3 { return error('common_parse_uint: integer overflow $s') }
+			else { return error('common_parse_uint: syntax error $s') }
+		}
+	}
+	return result
+}
+
+// the first returned value contains the parsed value,
+// the second returned value contains the error code (0 = OK, >1 = index of first non-parseable character + 1, -1 = wrong base, -2 = wrong bit size, -3 = overflow)
+pub fn common_parse_uint2(s string, _base int, _bit_size int) (u64, int) {
+	mut bit_size := _bit_size
+	mut base := _base
+	if s.len < 1 || !underscore_ok(s) {
+		// return error('parse_uint: syntax error $s')
+		return u64(0), 1
+	}
+	base0 := base == 0
+	mut start_index := 0
+	if 2 <= base && base <= 36 {
+		// valid base; nothing to do
+	} else if base == 0 {
+		// Look for octal, hex prefix.
+		base = 10
+		if s[0] == `0` {
+			if s.len >= 3 && byte_to_lower(s[1]) == `b` {
+				base = 2
+				start_index += 2
+			} else if s.len >= 3 && byte_to_lower(s[1]) == `o` {
+				base = 8
+				start_index += 2
+			} else if s.len >= 3 && byte_to_lower(s[1]) == `x` {
+				base = 16
+				start_index += 2
+			}
+			// manage leading zeros in decimal base's numbers
+			else if s.len >= 2 && (s[1] >= `0` && s[1] <= `9`) {
+				base = 10
+				start_index++
+			} else {
+				base = 8
+				start_index++
+			}
+		}
+	} else {
+		// return error('parse_uint: base error $s - $base')
+		return u64(0), -1
+	}
+	if bit_size == 0 {
+		bit_size = strconv.int_size
+	} else if bit_size < 0 || bit_size > 64 {
+		// return error('parse_uint: bitsize error $s - $bit_size')
+		return u64(0), -2
+	}
+	// Cutoff is the smallest number such that cutoff*base > maxUint64.
+	// Use compile-time constants for common cases.
+	cutoff := strconv.max_u64 / u64(base) + u64(1)
+	max_val := if bit_size == 64 { strconv.max_u64 } else { (u64(1) << u64(bit_size)) - u64(1) }
+	mut n := u64(0)
+	for i in start_index .. s.len {
+		c := s[i]
+		cl := byte_to_lower(c)
+		mut d := byte(0)
+		if c == `_` && base0 {
+			// underscore_ok already called
+			continue
+		} else if `0` <= c && c <= `9` {
+			d = c - `0`
+		} else if `a` <= cl && cl <= `z` {
+			d = cl - `a` + 10
+		} else {
+			return n, i + 1
+		}
+		if d >= byte(base) {
+			return n, i + 1
+		}
+		if n >= cutoff {
+			// n*base overflows
+			// return error('parse_uint: range error $s')
+			return max_val, -3
+		}
+		n *= u64(base)
+		n1 := n + u64(d)
+		if n1 < n || n1 > max_val {
+			// n+v overflows
+			// return error('parse_uint: range error $s')
+			return max_val, -3
+		}
+		n = n1
+	}
+	return n, 0
+}
+
+// parse_uint is like parse_int but for unsigned numbers.
+pub fn parse_uint(s string, _base int, _bit_size int) ?u64 {
+	return common_parse_uint(s, _base, _bit_size, true, true)
+}
+
+// common_parse_int is called by parse int and allows the parsing
+// to stop on non or invalid digit characters and return with an error
+pub fn common_parse_int(_s string, base int, _bit_size int, error_on_non_digit bool, error_on_high_digit bool) ?i64 {
+	mut s := _s
+	mut bit_size := _bit_size
+	if s.len < 1 {
+		// return error('parse_int: syntax error $s')
+		return i64(0)
+	}
+	// Pick off leading sign.
+	mut neg := false
+	if s[0] == `+` {
+		s = s[1..]
+	} else if s[0] == `-` {
+		neg = true
+		s = s[1..]
+	}
+	// Convert unsigned and check range.
+	// un := parse_uint(s, base, bit_size) or {
+	// return i64(0)
+	// }
+	un := common_parse_uint(s, base, bit_size, error_on_non_digit, error_on_high_digit) ?
+	if un == 0 {
+		return i64(0)
+	}
+	if bit_size == 0 {
+		bit_size = strconv.int_size
+	}
+	// TODO: check should u64(bit_size-1) be size of int (32)?
+	cutoff := u64(1) << u64(bit_size - 1)
+	if !neg && un >= cutoff {
+		// return error('parse_int: range error $s0')
+		return i64(cutoff - u64(1))
+	}
+	if neg && un > cutoff {
+		// return error('parse_int: range error $s0')
+		return -i64(cutoff)
+	}
+	return if neg { -i64(un) } else { i64(un) }
+}
+
+// parse_int interprets a string s in the given base (0, 2 to 36) and
+// bit size (0 to 64) and returns the corresponding value i.
+//
+// If the base argument is 0, the true base is implied by the string's
+// prefix: 2 for "0b", 8 for "0" or "0o", 16 for "0x", and 10 otherwise.
+// Also, for argument base 0 only, underscore characters are permitted
+// as defined by the Go syntax for integer literals.
+//
+// The bitSize argument specifies the integer type
+// that the result must fit into. Bit sizes 0, 8, 16, 32, and 64
+// correspond to int, int8, int16, int32, and int64.
+// If bitSize is below 0 or above 64, an error is returned.
+pub fn parse_int(_s string, base int, _bit_size int) ?i64 {
+	return common_parse_int(_s, base, _bit_size, true, true)
+}
+
+// atoi is equivalent to parse_int(s, 10, 0), converted to type int.
+pub fn atoi(s string) ?int {
+	if s == '' {
+		return error('strconv.atoi: parsing "$s": invalid syntax ')
+	}
+	if (strconv.int_size == 32 && (0 < s.len && s.len < 10))
+		|| (strconv.int_size == 64 && (0 < s.len && s.len < 19)) {
+		// Fast path for small integers that fit int type.
+		mut start_idx := 0
+		if s[0] == `-` || s[0] == `+` {
+			start_idx++
+			if s.len - start_idx < 1 {
+				// return 0, &NumError{fnAtoi, s0, ErrSyntax}
+				return error('strconv.atoi: parsing "$s": invalid syntax ')
+			}
+		}
+		mut n := 0
+		for i in start_idx .. s.len {
+			ch := s[i] - `0`
+			if ch > 9 {
+				// return 0, &NumError{fnAtoi, s0, ErrSyntax}
+				return error('strconv.atoi: parsing "$s": invalid syntax ')
+			}
+			n = n * 10 + int(ch)
+		}
+		return if s[0] == `-` { -n } else { n }
+	}
+	// Slow path for invalid, big, or underscored integers.
+	int64 := parse_int(s, 10, 0) ?
+	return int(int64)
+}
+
+// underscore_ok reports whether the underscores in s are allowed.
+// Checking them in this one function lets all the parsers skip over them simply.
+// Underscore must appear only between digits or between a base prefix and a digit.
+fn underscore_ok(s string) bool {
+	// saw tracks the last character (class) we saw:
+	// ^ for beginning of number,
+	// 0 for a digit or base prefix,
+	// _ for an underscore,
+	// ! for none of the above.
+	mut saw := `^`
+	mut i := 0
+	// Optional sign.
+	if s.len >= 1 && (s[0] == `-` || s[0] == `+`) {
+		i++
+	}
+	// Optional base prefix.
+	mut hex := false
+	if s.len - i >= 2 && s[i] == `0` && (byte_to_lower(s[i + 1]) == `b`
+		|| byte_to_lower(s[i + 1]) == `o` || byte_to_lower(s[i + 1]) == `x`) {
+		saw = `0` // base prefix counts as a digit for "underscore as digit separator"
+		hex = byte_to_lower(s[i + 1]) == `x`
+		i += 2
+	}
+	// Number proper.
+	for ; i < s.len; i++ {
+		// Digits are always okay.
+		if (`0` <= s[i] && s[i] <= `9`) || (hex && `a` <= byte_to_lower(s[i])
+			&& byte_to_lower(s[i]) <= `f`) {
+			saw = `0`
+			continue
+		}
+		// Underscore must follow digit.
+		if s[i] == `_` {
+			if saw != `0` {
+				return false
+			}
+			saw = `_`
+			continue
+		}
+		// Underscore must also be followed by digit.
+		if saw == `_` {
+			return false
+		}
+		// Saw non-digit, non-underscore.
+		saw = `!`
+	}
+	return saw != `_`
+}