172 lines
4.8 KiB
Rust
172 lines
4.8 KiB
Rust
/*
|
||
* meli - text_processing crate.
|
||
*
|
||
* Copyright 2017-2020 Manos Pitsidianakis
|
||
*
|
||
* This file is part of meli.
|
||
*
|
||
* meli is free software: you can redistribute it and/or modify
|
||
* it under the terms of the GNU General Public License as published by
|
||
* the Free Software Foundation, either version 3 of the License, or
|
||
* (at your option) any later version.
|
||
*
|
||
* meli is distributed in the hope that it will be useful,
|
||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
* GNU General Public License for more details.
|
||
*
|
||
* You should have received a copy of the GNU General Public License
|
||
* along with meli. If not, see <http://www.gnu.org/licenses/>.
|
||
*/
|
||
|
||
/*
|
||
* This is an implementation of wcwidth() and wcswidth() as defined in
|
||
* "The Single UNIX Specification, Version 2, The Open Group, 1997"
|
||
* <http://www.UNIX-systems.org/online.html>
|
||
*
|
||
* Markus Kuhn -- 2001-09-08 -- public domain
|
||
*/
|
||
|
||
// Update to Unicode 12
|
||
|
||
#[macro_export]
|
||
macro_rules! big_if_true {
|
||
($a:expr) => {
|
||
if $a {
|
||
1
|
||
} else {
|
||
0
|
||
}
|
||
};
|
||
}
|
||
|
||
type WChar = u32;
|
||
type Interval = (WChar, WChar);
|
||
|
||
pub struct CodePointsIterator<'a> {
|
||
rest: std::str::Chars<'a>,
|
||
}
|
||
|
||
/*
|
||
* UTF-8 uses a system of binary prefixes, in which the high bits of each byte mark whether it’s a single byte, the beginning of a multi-byte sequence, or a continuation byte; the remaining bits, concatenated, give the code point index. This table shows how it works:
|
||
*
|
||
* UTF-8 (binary) Code point (binary) Range
|
||
* 0xxxxxxx xxxxxxx U+0000–U+007F
|
||
* 110xxxxx 10yyyyyy xxxxxyyyyyy U+0080–U+07FF
|
||
* 1110xxxx 10yyyyyy 10zzzzzz xxxxyyyyyyzzzzzz U+0800–U+FFFF
|
||
* 11110xxx 10yyyyyy 10zzzzzz 10wwwwww xxxyyyyyyzzzzzzwwwwww U+10000–U+10FFFF
|
||
*
|
||
*/
|
||
impl<'a> Iterator for CodePointsIterator<'a> {
|
||
type Item = WChar;
|
||
|
||
fn next(&mut self) -> Option<WChar> {
|
||
self.rest.next().map(|c| c as WChar)
|
||
}
|
||
}
|
||
pub trait CodePointsIter {
|
||
fn code_points(&self) -> CodePointsIterator;
|
||
}
|
||
|
||
impl CodePointsIter for str {
|
||
fn code_points(&self) -> CodePointsIterator {
|
||
CodePointsIterator { rest: self.chars() }
|
||
}
|
||
}
|
||
impl CodePointsIter for &str {
|
||
fn code_points(&self) -> CodePointsIterator {
|
||
CodePointsIterator { rest: self.chars() }
|
||
}
|
||
}
|
||
|
||
/* auxiliary function for binary search in Interval table */
|
||
fn bisearch(ucs: WChar, table: &'static [Interval]) -> bool {
|
||
let mut min = 0;
|
||
let mut mid;
|
||
|
||
let mut max = table.len() - 1;
|
||
|
||
if ucs < table[0].0 || ucs > table[max].1 {
|
||
return false;
|
||
}
|
||
while max >= min {
|
||
mid = (min + max) / 2;
|
||
if ucs > table[mid].1 {
|
||
min = mid + 1;
|
||
} else if ucs < table[mid].0 {
|
||
max = mid - 1;
|
||
} else {
|
||
return true;
|
||
}
|
||
}
|
||
|
||
false
|
||
}
|
||
|
||
pub fn wcwidth(ucs: WChar) -> Option<usize> {
|
||
if bisearch(ucs, super::tables::ASCII) {
|
||
Some(1)
|
||
} else if bisearch(ucs, super::tables::PRIVATE) {
|
||
None
|
||
} else if bisearch(ucs, super::tables::NONPRINT) {
|
||
None
|
||
} else if bisearch(ucs, super::tables::COMBINING) {
|
||
None
|
||
} else if bisearch(ucs, super::tables::DOUBLEWIDE) {
|
||
Some(2)
|
||
} else if bisearch(ucs, super::tables::AMBIGUOUS) {
|
||
Some(1)
|
||
} else if bisearch(ucs, super::tables::UNASSIGNED) {
|
||
Some(2)
|
||
} else if bisearch(ucs, super::tables::WIDENEDIN9) {
|
||
Some(2)
|
||
} else {
|
||
Some(1)
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn test_wcwidth() {
|
||
assert_eq!(
|
||
&"abc\0".code_points().collect::<Vec<_>>(),
|
||
&[0x61, 0x62, 0x63, 0x0]
|
||
);
|
||
assert_eq!(&"●".code_points().collect::<Vec<_>>(), &[0x25cf]);
|
||
assert_eq!(&"📎".code_points().collect::<Vec<_>>(), &[0x1f4ce]);
|
||
assert_eq!(
|
||
&"𐼹𐼺𐼻𐼼𐼽".code_points().collect::<Vec<_>>(),
|
||
&[0x10F39, 0x10F3A, 0x10F3B, 0x10F3C, 0x10F3D]
|
||
); // Sogdian alphabet
|
||
assert_eq!(
|
||
&"𐼹a𐼽b".code_points().collect::<Vec<_>>(),
|
||
&[0x10F39, 0x61, 0x10F3D, 0x62]
|
||
); // Sogdian alphabet
|
||
assert_eq!(
|
||
&"📎\u{FE0E}".code_points().collect::<Vec<_>>(),
|
||
&[0x1f4ce, 0xfe0e]
|
||
);
|
||
use crate::text_processing::grapheme_clusters::TextProcessing;
|
||
assert_eq!("●".grapheme_width(), 1);
|
||
assert_eq!("●📎".grapheme_width(), 3);
|
||
assert_eq!("●\u{FE0E}📎\u{FE0E}".grapheme_width(), 3);
|
||
assert_eq!("🎃".grapheme_width(), 2);
|
||
assert_eq!("👻".grapheme_width(), 2);
|
||
}
|
||
|
||
pub fn wcswidth(mut pwcs: WChar, mut n: usize) -> Option<usize> {
|
||
let mut width = 0;
|
||
|
||
while pwcs > 0 && n > 0 {
|
||
if let Some(w) = wcwidth(pwcs) {
|
||
width += w;
|
||
} else {
|
||
return None;
|
||
}
|
||
|
||
pwcs += 1;
|
||
n -= 1;
|
||
}
|
||
|
||
Some(width)
|
||
}
|