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use std::str;
pub struct Utf8Buffer<'r> {
buf: &'r mut [u8],
idx: usize
}
impl<'r> Utf8Buffer<'r> {
pub fn new(b: &'r mut [u8]) -> Utf8Buffer<'r> {
Utf8Buffer { buf: b, idx: 0 }
}
pub fn reset(&mut self) {
self.idx = 0
}
pub fn as_str(&self) -> &str {
unsafe { str::from_utf8_unchecked(&self.buf[0 .. self.idx]) }
}
pub fn is_full(&self) -> bool {
self.idx >= self.buf.len()
}
pub fn push(&mut self, c: char) {
let len = c.len_utf8();
if self.idx + len > self.buf.len() {
return ()
}
self.idx += c.encode_utf8(&mut self.buf[self.idx ..]).len()
}
}
pub trait Buffer {
fn push(&mut self, c: char);
fn is_full(&self) -> bool;
}
impl Buffer for String {
fn push(&mut self, c: char) { self.push(c) }
fn is_full(&self) -> bool { false }
}
impl<'r> Buffer for Utf8Buffer<'r> {
fn push(&mut self, c: char) { self.push(c) }
fn is_full(&self) -> bool { self.is_full() }
}