v/builtin/string_builder.v

37 lines
691 B
Go

// Copyright (c) 2019 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 builtin
struct StringBuilder {
buf []byte
len int
}
fn new_string_builder(initial_size int) StringBuilder {
return StringBuilder {
buf: new_array(0, initial_size, sizeof(byte))
}
}
fn (b mut StringBuilder) write(s string) {
b.buf._push_many(s.str, s.len)
b.len += s.len
}
fn (b mut StringBuilder) writeln(s string) {
b.buf._push_many(s.str, s.len)
b.buf << `\n`
b.len += s.len + 1
}
fn (b StringBuilder) str() string {
return tos(b.buf.data, b.len)
}
fn (b StringBuilder) cut(n int) {
b.len -= n
}