unicode_normalization/
replace.rs

1// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2// file at the top-level directory of this distribution and at
3// http://rust-lang.org/COPYRIGHT.
4//
5// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8// option. This file may not be copied, modified, or distributed
9// except according to those terms.
10use core::{
11    fmt::{self, Write},
12    iter::FusedIterator,
13};
14use tinyvec::ArrayVec;
15
16/// External iterator for replacements for a string's characters.
17#[derive(Clone)]
18pub struct Replacements<I> {
19    iter: I,
20    // At this time, the longest replacement sequence has length 2, so we just
21    // need buffer space for 1 codepoint.
22    buffer: Option<char>,
23}
24
25#[inline]
26pub fn new_cjk_compat_variants<I: Iterator<Item = char>>(iter: I) -> Replacements<I> {
27    Replacements { iter, buffer: None }
28}
29
30impl<I: Iterator<Item = char>> Iterator for Replacements<I> {
31    type Item = char;
32
33    #[inline]
34    fn next(&mut self) -> Option<char> {
35        if let Some(c) = self.buffer.take() {
36            return Some(c);
37        }
38
39        match self.iter.next() {
40            Some(ch) => {
41                // At this time, the longest replacement sequence has length 2.
42                let mut buffer = ArrayVec::<[char; 2]>::new();
43                super::char::decompose_cjk_compat_variants(ch, |d| buffer.push(d));
44                self.buffer = buffer.get(1).copied();
45                Some(buffer[0])
46            }
47            None => None,
48        }
49    }
50
51    fn size_hint(&self) -> (usize, Option<usize>) {
52        let (lower, _) = self.iter.size_hint();
53        (lower, None)
54    }
55}
56
57impl<I: Iterator<Item = char> + FusedIterator> FusedIterator for Replacements<I> {}
58
59impl<I: Iterator<Item = char> + Clone> fmt::Display for Replacements<I> {
60    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
61        for c in self.clone() {
62            f.write_char(c)?;
63        }
64        Ok(())
65    }
66}
unicode_normalization/replace.rs

unicode_normalization/
replace.rs
