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v/vlib/strings/builder.js.v
2022-01-04 12:21:12 +03:00

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V

// Copyright (c) 2019-2022 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
/*
pub struct Builder {
mut:
buf []byte
pub mut:
len int
initial_size int = 1
}*/
pub type Builder = []byte
pub fn new_builder(initial_size int) Builder {
return []byte{cap: initial_size}
}
pub fn (mut b Builder) write_b(data byte) {
b << data
}
pub fn (mut b Builder) write(data []byte) ?int {
if data.len == 0 {
return 0
}
b << data
return data.len
}
pub fn (b &Builder) byte_at(n int) byte {
unsafe {
return b[n]
}
}
pub fn (mut b Builder) write_string(s string) {
if s.len == 0 {
return
}
for c in s {
b << c
}
}
pub fn (mut b Builder) writeln(s string) {
if s.len > 0 {
b.write_string(s)
}
b << 10
}
pub fn (mut b Builder) str() string {
s := ''
#for (const c of b.val.arr.arr)
#s.str += String.fromCharCode(+c)
b.trim(0)
return s
}
pub fn (mut b Builder) cut_last(n int) string {
cut_pos := b.len - n
x := b[cut_pos..]
res := x.bytestr()
b.trim(cut_pos)
return res
}
pub fn (mut b Builder) go_back_to(pos int) {
b.trim(pos)
}
// 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_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)
}
pub fn (mut b Builder) write_runes(runes []rune) {
for r in runes {
res := r.str()
#res.str = String.fromCharCode(r.val)
b << res.bytes()
}
}
// after(6) returns 'world'
// buf == 'hello world'
pub fn (mut b Builder) after(n int) string {
if n >= b.len {
return ''
}
x := b.slice(n, b.len)
return x.bytestr()
}
// last_n(5) returns 'world'
// buf == 'hello world'
pub fn (b &Builder) last_n(n int) string {
if n >= b.len {
return ''
}
x := b.slice(b.len - n, b.len)
return x.bytestr()
}