1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169
// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use crate::decompose::Decompositions;
use core::{
fmt::{self, Write},
iter::FusedIterator,
};
use tinyvec::TinyVec;
#[derive(Clone)]
enum RecompositionState {
Composing,
Purging(usize),
Finished(usize),
}
/// External iterator for a string recomposition's characters.
#[derive(Clone)]
pub struct Recompositions<I> {
iter: Decompositions<I>,
state: RecompositionState,
buffer: TinyVec<[char; 4]>,
composee: Option<char>,
last_ccc: Option<u8>,
}
impl<I: Iterator<Item = char>> Recompositions<I> {
/// Create a new recomposition iterator for canonical compositions (NFC)
///
/// Note that this iterator can also be obtained by directly calling [`.nfc()`](crate::UnicodeNormalization::nfc)
/// on the iterator.
#[inline]
pub fn new_canonical(iter: I) -> Self {
Recompositions {
iter: Decompositions::new_canonical(iter),
state: self::RecompositionState::Composing,
buffer: TinyVec::new(),
composee: None,
last_ccc: None,
}
}
/// Create a new recomposition iterator for compatability compositions (NFkC)
///
/// Note that this iterator can also be obtained by directly calling [`.nfkc()`](crate::UnicodeNormalization::nfkc)
/// on the iterator.
#[inline]
pub fn new_compatible(iter: I) -> Self {
Recompositions {
iter: Decompositions::new_compatible(iter),
state: self::RecompositionState::Composing,
buffer: TinyVec::new(),
composee: None,
last_ccc: None,
}
}
}
impl<I: Iterator<Item = char>> Iterator for Recompositions<I> {
type Item = char;
#[inline]
fn next(&mut self) -> Option<char> {
use self::RecompositionState::*;
loop {
match self.state {
Composing => {
for ch in self.iter.by_ref() {
let ch_class = super::char::canonical_combining_class(ch);
let k = match self.composee {
None => {
if ch_class != 0 {
return Some(ch);
}
self.composee = Some(ch);
continue;
}
Some(k) => k,
};
match self.last_ccc {
None => match super::char::compose(k, ch) {
Some(r) => {
self.composee = Some(r);
continue;
}
None => {
if ch_class == 0 {
self.composee = Some(ch);
return Some(k);
}
self.buffer.push(ch);
self.last_ccc = Some(ch_class);
}
},
Some(l_class) => {
if l_class >= ch_class {
// `ch` is blocked from `composee`
if ch_class == 0 {
self.composee = Some(ch);
self.last_ccc = None;
self.state = Purging(0);
return Some(k);
}
self.buffer.push(ch);
self.last_ccc = Some(ch_class);
continue;
}
match super::char::compose(k, ch) {
Some(r) => {
self.composee = Some(r);
continue;
}
None => {
self.buffer.push(ch);
self.last_ccc = Some(ch_class);
}
}
}
}
}
self.state = Finished(0);
if self.composee.is_some() {
return self.composee.take();
}
}
Purging(next) => match self.buffer.get(next).cloned() {
None => {
self.buffer.clear();
self.state = Composing;
}
s => {
self.state = Purging(next + 1);
return s;
}
},
Finished(next) => match self.buffer.get(next).cloned() {
None => {
self.buffer.clear();
return self.composee.take();
}
s => {
self.state = Finished(next + 1);
return s;
}
},
}
}
}
}
impl<I: Iterator<Item = char> + FusedIterator> FusedIterator for Recompositions<I> {}
impl<I: Iterator<Item = char> + Clone> fmt::Display for Recompositions<I> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for c in self.clone() {
f.write_char(c)?;
}
Ok(())
}
}