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authorIndrajith K L2022-12-03 17:00:20 +0530
committerIndrajith K L2022-12-03 17:00:20 +0530
commitf5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch)
tree2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/strings/builder.v
downloadcli-tools-windows-master.tar.gz
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Adds most of the toolsHEADmaster
Diffstat (limited to 'v_windows/v/vlib/strings/builder.v')
-rw-r--r--v_windows/v/vlib/strings/builder.v163
1 files changed, 163 insertions, 0 deletions
diff --git a/v_windows/v/vlib/strings/builder.v b/v_windows/v/vlib/strings/builder.v
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+// 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.
+module strings
+
+// strings.Builder is used to efficiently append many strings to a large
+// dynamically growing buffer, then use the resulting large string. Using
+// a string builder is much better for performance/memory usage than doing
+// constantly string concatenation.
+pub type Builder = []byte
+
+// new_builder returns a new string builder, with an initial capacity of `initial_size`
+pub fn new_builder(initial_size int) Builder {
+ return Builder([]byte{cap: initial_size})
+}
+
+// write_ptr writes `len` bytes provided byteptr to the accumulated buffer
+[unsafe]
+pub fn (mut b Builder) write_ptr(ptr &byte, len int) {
+ if len == 0 {
+ return
+ }
+ unsafe { b.push_many(ptr, len) }
+}
+
+// write_rune appends a single rune to the accumulated buffer
+[manualfree]
+pub fn (mut b Builder) write_rune(r rune) {
+ mut buffer := [5]byte{}
+ res := unsafe { utf32_to_str_no_malloc(u32(r), &buffer[0]) }
+ if res.len == 0 {
+ return
+ }
+ unsafe { b.push_many(res.str, res.len) }
+}
+
+// write_runes appends all the given runes to the accumulated buffer
+pub fn (mut b Builder) write_runes(runes []rune) {
+ mut buffer := [5]byte{}
+ for r in runes {
+ res := unsafe { utf32_to_str_no_malloc(u32(r), &buffer[0]) }
+ if res.len == 0 {
+ continue
+ }
+ unsafe { b.push_many(res.str, res.len) }
+ }
+}
+
+// write_b appends a single `data` byte to the accumulated buffer
+pub fn (mut b Builder) write_b(data byte) {
+ b << data
+}
+
+// write implements the Writer interface
+pub fn (mut b Builder) write(data []byte) ?int {
+ if data.len == 0 {
+ return 0
+ }
+ b << data
+ return data.len
+}
+
+[inline]
+pub fn (b &Builder) byte_at(n int) byte {
+ return unsafe { (&[]byte(b))[n] }
+}
+
+// write appends the string `s` to the buffer
+[inline]
+pub fn (mut b Builder) write_string(s string) {
+ if s.len == 0 {
+ return
+ }
+ unsafe { b.push_many(s.str, s.len) }
+ // for c in s {
+ // b.buf << c
+ // }
+ // b.buf << []byte(s) // TODO
+}
+
+// go_back discards the last `n` bytes from the buffer
+pub fn (mut b Builder) go_back(n int) {
+ b.trim(b.len - n)
+}
+
+// cut_last cuts the last `n` bytes from the buffer and returns them
+pub fn (mut b Builder) cut_last(n int) string {
+ cut_pos := b.len - n
+ x := unsafe { (&[]byte(b))[cut_pos..] }
+ res := x.bytestr()
+ b.trim(cut_pos)
+ return res
+}
+
+// cut_to cuts the string after `pos` and returns it.
+// if `pos` is superior to builder length, returns an empty string
+// and cancel further operations
+pub fn (mut b Builder) cut_to(pos int) string {
+ if pos > b.len {
+ return ''
+ }
+ return b.cut_last(b.len - pos)
+}
+
+// go_back_to resets the buffer to the given position `pos`
+// NB: pos should be < than the existing buffer length.
+pub fn (mut b Builder) go_back_to(pos int) {
+ b.trim(pos)
+}
+
+// writeln appends the string `s`, and then a newline character.
+[inline]
+pub fn (mut b Builder) writeln(s string) {
+ // for c in s {
+ // b.buf << c
+ // }
+ if s.len > 0 {
+ unsafe { b.push_many(s.str, s.len) }
+ }
+ // b.buf << []byte(s) // TODO
+ b << byte(`\n`)
+}
+
+// last_n(5) returns 'world'
+// buf == 'hello world'
+pub fn (b &Builder) last_n(n int) string {
+ if n > b.len {
+ return ''
+ }
+ x := unsafe { (&[]byte(b))[b.len - n..] }
+ return x.bytestr()
+}
+
+// after(6) returns 'world'
+// buf == 'hello world'
+pub fn (b &Builder) after(n int) string {
+ if n >= b.len {
+ return ''
+ }
+ x := unsafe { (&[]byte(b))[n..] }
+ return x.bytestr()
+}
+
+// str returns a copy of all of the accumulated buffer content.
+// NB: after a call to b.str(), the builder b should not be
+// used again, you need to call b.free() first, or just leave
+// it to be freed by -autofree when it goes out of scope.
+// The returned string *owns* its own separate copy of the
+// accumulated data that was in the string builder, before the
+// .str() call.
+pub fn (mut b Builder) str() string {
+ b << byte(0)
+ bcopy := unsafe { &byte(memdup(b.data, b.len)) }
+ s := unsafe { bcopy.vstring_with_len(b.len - 1) }
+ b.trim(0)
+ return s
+}
+
+// free is for manually freeing the contents of the buffer
+[unsafe]
+pub fn (mut b Builder) free() {
+ unsafe { free(b.data) }
+}