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Diffstat (limited to 'vendor/unicode-normalization/src/decompose.rs')
| -rw-r--r-- | vendor/unicode-normalization/src/decompose.rs | 173 |
1 files changed, 0 insertions, 173 deletions
diff --git a/vendor/unicode-normalization/src/decompose.rs b/vendor/unicode-normalization/src/decompose.rs deleted file mode 100644 index 2c73383a..00000000 --- a/vendor/unicode-normalization/src/decompose.rs +++ /dev/null @@ -1,173 +0,0 @@ -// 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 core::fmt::{self, Write}; -use core::iter::{Fuse, FusedIterator}; -use core::ops::Range; -use tinyvec::TinyVec; - -#[derive(Clone)] -enum DecompositionType { - Canonical, - Compatible, -} - -/// External iterator for a string decomposition's characters. -#[derive(Clone)] -pub struct Decompositions<I> { - kind: DecompositionType, - iter: Fuse<I>, - - // This buffer stores pairs of (canonical combining class, character), - // pushed onto the end in text order. - // - // It's divided into up to three sections: - // 1) A prefix that is free space; - // 2) "Ready" characters which are sorted and ready to emit on demand; - // 3) A "pending" block which stills needs more characters for us to be able - // to sort in canonical order and is not safe to emit. - buffer: TinyVec<[(u8, char); 4]>, - ready: Range<usize>, -} - -impl<I: Iterator<Item = char>> Decompositions<I> { - /// Create a new decomposition iterator for canonical decompositions (NFD) - /// - /// Note that this iterator can also be obtained by directly calling [`.nfd()`](crate::UnicodeNormalization::nfd) - /// on the iterator. - #[inline] - pub fn new_canonical(iter: I) -> Decompositions<I> { - Decompositions { - kind: self::DecompositionType::Canonical, - iter: iter.fuse(), - buffer: TinyVec::new(), - ready: 0..0, - } - } - - /// Create a new decomposition iterator for compatability decompositions (NFkD) - /// - /// Note that this iterator can also be obtained by directly calling [`.nfd()`](crate::UnicodeNormalization::nfd) - /// on the iterator. - #[inline] - pub fn new_compatible(iter: I) -> Decompositions<I> { - Decompositions { - kind: self::DecompositionType::Compatible, - iter: iter.fuse(), - buffer: TinyVec::new(), - ready: 0..0, - } - } -} - -impl<I> Decompositions<I> { - #[inline] - fn push_back(&mut self, ch: char) { - let class = super::char::canonical_combining_class(ch); - - if class == 0 { - self.sort_pending(); - self.buffer.push((class, ch)); - self.ready.end = self.buffer.len(); - } else { - self.buffer.push((class, ch)); - } - } - - #[inline] - fn sort_pending(&mut self) { - // NB: `sort_by_key` is stable, so it will preserve the original text's - // order within a combining class. - self.buffer[self.ready.end..].sort_by_key(|k| k.0); - } - - #[inline] - fn reset_buffer(&mut self) { - // Equivalent to `self.buffer.drain(0..self.ready.end)` - // but faster than drain() if the buffer is a SmallVec or TinyVec - let pending = self.buffer.len() - self.ready.end; - for i in 0..pending { - self.buffer[i] = self.buffer[i + self.ready.end]; - } - self.buffer.truncate(pending); - self.ready = 0..0; - } - - #[inline] - fn increment_next_ready(&mut self) { - let next = self.ready.start + 1; - if next == self.ready.end { - self.reset_buffer(); - } else { - self.ready.start = next; - } - } -} - -impl<I: Iterator<Item = char>> Iterator for Decompositions<I> { - type Item = char; - - #[inline] - fn next(&mut self) -> Option<char> { - while self.ready.end == 0 { - match (self.iter.next(), &self.kind) { - (Some(ch), &DecompositionType::Canonical) => { - super::char::decompose_canonical(ch, |d| self.push_back(d)); - } - (Some(ch), &DecompositionType::Compatible) => { - super::char::decompose_compatible(ch, |d| self.push_back(d)); - } - (None, _) => { - if self.buffer.is_empty() { - return None; - } else { - self.sort_pending(); - self.ready.end = self.buffer.len(); - - // This implementation means that we can call `next` - // on an exhausted iterator; the last outer `next` call - // will result in an inner `next` call. To make this - // safe, we use `fuse`. - break; - } - } - } - } - - // We can assume here that, if `self.ready.end` is greater than zero, - // it's also greater than `self.ready.start`. That's because we only - // increment `self.ready.start` inside `increment_next_ready`, and - // whenever it reaches equality with `self.ready.end`, we reset both - // to zero, maintaining the invariant that: - // self.ready.start < self.ready.end || self.ready.end == self.ready.start == 0 - // - // This less-than-obviously-safe implementation is chosen for performance, - // minimizing the number & complexity of branches in `next` in the common - // case of buffering then unbuffering a single character with each call. - let (_, ch) = self.buffer[self.ready.start]; - self.increment_next_ready(); - Some(ch) - } - - fn size_hint(&self) -> (usize, Option<usize>) { - let (lower, _) = self.iter.size_hint(); - (lower, None) - } -} - -impl<I: Iterator<Item = char> + FusedIterator> FusedIterator for Decompositions<I> {} - -impl<I: Iterator<Item = char> + Clone> fmt::Display for Decompositions<I> { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - for c in self.clone() { - f.write_char(c)?; - } - Ok(()) - } -} |