498 lines
14 KiB
Rust
498 lines
14 KiB
Rust
/*
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* This is an implementation of wcwidth() and wcswidth() as defined in
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* "The Single UNIX Specification, Version 2, The Open Group, 1997"
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* <http://www.UNIX-systems.org/online.html>
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*
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* Markus Kuhn -- 2001-09-08 -- public domain
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*/
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// TODO: Spacing widths
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// Update to Unicode 12
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#[macro_export]
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macro_rules! big_if_true {
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($a:expr) => {
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if $a {
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1
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} else {
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0
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}
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};
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}
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type WChar = u32;
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type Interval = (WChar, WChar);
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pub struct CodePointsIterator<'a> {
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rest: &'a [u8],
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}
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/*
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* 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:
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*
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* UTF-8 (binary) Code point (binary) Range
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* 0xxxxxxx xxxxxxx U+0000–U+007F
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* 110xxxxx 10yyyyyy xxxxxyyyyyy U+0080–U+07FF
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* 1110xxxx 10yyyyyy 10zzzzzz xxxxyyyyyyzzzzzz U+0800–U+FFFF
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* 11110xxx 10yyyyyy 10zzzzzz 10wwwwww xxxyyyyyyzzzzzzwwwwww U+10000–U+10FFFF
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*
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*/
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impl<'a> Iterator for CodePointsIterator<'a> {
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type Item = WChar;
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fn next(&mut self) -> Option<WChar> {
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if self.rest.is_empty() {
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return None;
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}
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/* Input is UTF-8 valid strings, guaranteed by Rust's std */
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if self.rest[0] & 0b1000_0000 == 0x0 {
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let ret: WChar = self.rest[0] as WChar;
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self.rest = &self.rest[1..];
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return Some(ret);
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}
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if self.rest[0] & 0b1110_0000 == 0b1100_0000 {
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let ret: WChar = (self.rest[0] as WChar & 0b0001_1111).rotate_left(6)
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+ (self.rest[1] as WChar & 0b0111_1111);
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self.rest = &self.rest[2..];
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return Some(ret);
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}
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if self.rest[0] & 0b1111_0000 == 0b1110_0000 {
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let ret: WChar = (self.rest[0] as WChar & 0b0000_0111).rotate_left(12)
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+ (self.rest[1] as WChar & 0b0011_1111).rotate_left(6)
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+ (self.rest[2] as WChar & 0b0011_1111);
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self.rest = &self.rest[3..];
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return Some(ret);
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}
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let ret: WChar = (self.rest[0] as WChar & 0b0000_0111).rotate_left(18)
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+ (self.rest[1] as WChar & 0b0011_1111).rotate_left(12)
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+ (self.rest[2] as WChar & 0b0011_1111).rotate_left(6)
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+ (self.rest[3] as WChar & 0b0011_1111);
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self.rest = &self.rest[4..];
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Some(ret)
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}
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}
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pub trait CodePointsIter {
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fn code_points(&self) -> CodePointsIterator;
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}
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impl CodePointsIter for str {
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fn code_points(&self) -> CodePointsIterator {
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CodePointsIterator {
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rest: self.as_bytes(),
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}
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}
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}
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impl CodePointsIter for &str {
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fn code_points(&self) -> CodePointsIterator {
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CodePointsIterator {
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rest: self.as_bytes(),
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}
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}
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}
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/* auxiliary function for binary search in Interval table */
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fn bisearch(ucs: WChar, table: &'static [Interval]) -> bool {
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let mut min = 0;
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let mut mid;
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let mut max = table.len() - 1;
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if ucs < table[0].0 || ucs > table[max].1 {
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return true;
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}
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while max >= min {
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mid = (min + max) / 2;
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if ucs > table[mid].1 {
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min = mid + 1;
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} else if ucs < table[mid].0 {
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max = mid - 1;
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} else {
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return true;
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}
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}
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return false;
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}
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/* The following functions define the column width of an ISO 10646
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* character as follows:
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*
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* - The null character (U+0000) has a column width of 0.
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*
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* - Other C0/C1 control characters and DEL will lead to a return
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* value of -1.
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*
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* - Non-spacing and enclosing combining characters (general
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* category code Mn or Me in the Unicode database) have a
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* column width of 0.
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*
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* - Other format characters (general category code Cf in the Unicode
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* database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
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*
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* - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
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* have a column width of 0.
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*
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* - Spacing characters in the East Asian Wide (W) or East Asian
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* FullWidth (F) category as defined in Unicode Technical
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* Report #11 have a column width of 2.
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*
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* - All remaining characters (including all printable
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* ISO 8859-1 and WGL4 characters, Unicode control characters,
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* etc.) have a column width of 1.
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*
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* This implementation assumes that wchar_t characters are encoded
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* in ISO 10646.
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*/
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pub fn wcwidth(ucs: WChar) -> Option<usize> {
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/* sorted list of non-overlapping intervals of non-spacing characters */
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let combining: &'static [Interval] = &[
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(0x0300, 0x034E),
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(0x0360, 0x0362),
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(0x0483, 0x0486),
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(0x0488, 0x0489),
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(0x0591, 0x05A1),
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(0x05A3, 0x05B9),
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(0x05BB, 0x05BD),
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(0x05BF, 0x05BF),
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(0x05C1, 0x05C2),
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(0x05C4, 0x05C4),
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(0x064B, 0x0655),
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(0x0670, 0x0670),
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(0x06D6, 0x06E4),
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(0x06E7, 0x06E8),
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(0x06EA, 0x06ED),
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(0x070F, 0x070F),
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(0x0711, 0x0711),
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(0x0730, 0x074A),
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(0x07A6, 0x07B0),
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(0x0901, 0x0902),
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(0x093C, 0x093C),
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(0x0941, 0x0948),
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(0x094D, 0x094D),
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(0x0951, 0x0954),
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(0x0962, 0x0963),
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(0x0981, 0x0981),
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(0x09BC, 0x09BC),
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(0x09C1, 0x09C4),
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(0x09CD, 0x09CD),
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(0x09E2, 0x09E3),
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(0x0A02, 0x0A02),
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(0x0A3C, 0x0A3C),
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(0x0A41, 0x0A42),
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(0x0A47, 0x0A48),
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(0x0A4B, 0x0A4D),
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(0x0A70, 0x0A71),
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(0x0A81, 0x0A82),
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(0x0ABC, 0x0ABC),
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(0x0AC1, 0x0AC5),
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(0x0AC7, 0x0AC8),
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(0x0ACD, 0x0ACD),
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(0x0B01, 0x0B01),
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(0x0B3C, 0x0B3C),
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(0x0B3F, 0x0B3F),
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(0x0B41, 0x0B43),
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(0x0B4D, 0x0B4D),
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(0x0B56, 0x0B56),
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(0x0B82, 0x0B82),
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(0x0BC0, 0x0BC0),
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(0x0BCD, 0x0BCD),
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(0x0C3E, 0x0C40),
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(0x0C46, 0x0C48),
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(0x0C4A, 0x0C4D),
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(0x0C55, 0x0C56),
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(0x0CBF, 0x0CBF),
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(0x0CC6, 0x0CC6),
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(0x0CCC, 0x0CCD),
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(0x0D41, 0x0D43),
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(0x0D4D, 0x0D4D),
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(0x0DCA, 0x0DCA),
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(0x0DD2, 0x0DD4),
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(0x0DD6, 0x0DD6),
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(0x0E31, 0x0E31),
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(0x0E34, 0x0E3A),
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(0x0E47, 0x0E4E),
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(0x0EB1, 0x0EB1),
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(0x0EB4, 0x0EB9),
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(0x0EBB, 0x0EBC),
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(0x0EC8, 0x0ECD),
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(0x0F18, 0x0F19),
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(0x0F35, 0x0F35),
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(0x0F37, 0x0F37),
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(0x0F39, 0x0F39),
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(0x0F71, 0x0F7E),
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(0x0F80, 0x0F84),
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(0x0F86, 0x0F87),
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(0x0F90, 0x0F97),
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(0x0F99, 0x0FBC),
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(0x0FC6, 0x0FC6),
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(0x102D, 0x1030),
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(0x1032, 0x1032),
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(0x1036, 0x1037),
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(0x1039, 0x1039),
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(0x1058, 0x1059),
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(0x1160, 0x11FF),
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(0x17B7, 0x17BD),
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(0x17C6, 0x17C6),
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(0x17C9, 0x17D3),
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(0x180B, 0x180E),
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(0x18A9, 0x18A9),
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(0x200B, 0x200F),
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(0x202A, 0x202E),
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(0x206A, 0x206F),
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(0x20D0, 0x20E3),
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(0x302A, 0x302F),
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(0x3099, 0x309A),
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(0xFB1E, 0xFB1E),
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(0xFE20, 0xFE23),
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(0xFEFF, 0xFEFF),
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(0xFFF9, 0xFFFB),
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];
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/* test for 8-bit control characters */
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if ucs == 0 {
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return Some(0);
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}
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if ucs < 32 || (ucs >= 0x7f && ucs < 0xa0) {
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return None;
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}
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/* binary search in table of non-spacing characters */
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if bisearch(ucs, combining) {
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return Some(1);
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}
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/* if we arrive here, ucs is not a combining or C0/C1 control character */
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return Some(
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1 + big_if_true!(
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ucs >= 0x1100
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&& (ucs <= 0x115f || /* Hangul Jamo init. consonants */
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(ucs >= 0x2e80 && ucs <= 0xa4cf && (ucs & !0x0011) != 0x300a &&
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ucs != 0x303f) || /* CJK ... Yi */
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(ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
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(ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */
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(ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
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(ucs >= 0xff00 && ucs <= 0xff5f) || /* Fullwidth Forms */
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(ucs >= 0xffe0 && ucs <= 0xffe6) ||
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(ucs >= 0x20000 && ucs <= 0x2ffff))
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),
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);
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}
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fn wcswidth(mut pwcs: WChar, mut n: usize) -> Option<usize> {
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let mut width = 0;
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while pwcs > 0 && n > 0 {
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if let Some(w) = wcwidth(pwcs) {
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width += w;
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} else {
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return None;
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}
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pwcs += 1;
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n -= 1;
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}
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return Some(width);
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}
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/*
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* The following function is the same as wcwidth(), except that
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* spacing characters in the East Asian Ambiguous (A) category as
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* defined in Unicode Technical Report #11 have a column width of 2.
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* This experimental variant might be useful for users of CJK legacy
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* encodings who want to migrate to UCS. It is not otherwise
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* recommended for general use.
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*/
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pub fn wcwidth_cjk(ucs: WChar) -> Option<usize> {
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/* sorted list of non-overlapping intervals of East Asian Ambiguous
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* characters */
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let ambiguous: &'static [Interval] = &[
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(0x00A1, 0x00A1),
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(0x00A4, 0x00A4),
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(0x00A7, 0x00A8),
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(0x00AA, 0x00AA),
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(0x00AD, 0x00AE),
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(0x00B0, 0x00B4),
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(0x00B6, 0x00BA),
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(0x00BC, 0x00BF),
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(0x00C6, 0x00C6),
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(0x00D0, 0x00D0),
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(0x00D7, 0x00D8),
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(0x00DE, 0x00E1),
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(0x00E6, 0x00E6),
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(0x00E8, 0x00EA),
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(0x00EC, 0x00ED),
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(0x00F0, 0x00F0),
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(0x00F2, 0x00F3),
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(0x00F7, 0x00FA),
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(0x00FC, 0x00FC),
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(0x00FE, 0x00FE),
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(0x0101, 0x0101),
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(0x0111, 0x0111),
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(0x0113, 0x0113),
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(0x011B, 0x011B),
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(0x0126, 0x0127),
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(0x012B, 0x012B),
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(0x0131, 0x0133),
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(0x0138, 0x0138),
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(0x013F, 0x0142),
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(0x0144, 0x0144),
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(0x0148, 0x014B),
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(0x014D, 0x014D),
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(0x0152, 0x0153),
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(0x0166, 0x0167),
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(0x016B, 0x016B),
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(0x01CE, 0x01CE),
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(0x01D0, 0x01D0),
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(0x01D2, 0x01D2),
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(0x01D4, 0x01D4),
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(0x01D6, 0x01D6),
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(0x01D8, 0x01D8),
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(0x01DA, 0x01DA),
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(0x01DC, 0x01DC),
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(0x0251, 0x0251),
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(0x0261, 0x0261),
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(0x02C4, 0x02C4),
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(0x02C7, 0x02C7),
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(0x02C9, 0x02CB),
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(0x02CD, 0x02CD),
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(0x02D0, 0x02D0),
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(0x02D8, 0x02DB),
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(0x02DD, 0x02DD),
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(0x02DF, 0x02DF),
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(0x0300, 0x034E),
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(0x0360, 0x0362),
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(0x0391, 0x03A1),
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(0x03A3, 0x03A9),
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(0x03B1, 0x03C1),
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(0x03C3, 0x03C9),
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(0x0401, 0x0401),
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(0x0410, 0x044F),
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(0x0451, 0x0451),
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(0x2010, 0x2010),
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(0x2013, 0x2016),
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(0x2018, 0x2019),
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(0x201C, 0x201D),
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(0x2020, 0x2022),
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(0x2024, 0x2027),
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(0x2030, 0x2030),
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(0x2032, 0x2033),
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(0x2035, 0x2035),
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(0x203B, 0x203B),
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(0x203E, 0x203E),
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(0x2074, 0x2074),
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(0x207F, 0x207F),
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(0x2081, 0x2084),
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(0x20AC, 0x20AC),
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(0x2103, 0x2103),
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(0x2105, 0x2105),
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(0x2109, 0x2109),
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(0x2113, 0x2113),
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(0x2116, 0x2116),
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(0x2121, 0x2122),
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(0x2126, 0x2126),
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(0x212B, 0x212B),
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(0x2153, 0x2155),
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(0x215B, 0x215E),
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(0x2160, 0x216B),
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(0x2170, 0x2179),
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(0x2190, 0x2199),
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(0x21B8, 0x21B9),
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(0x21D2, 0x21D2),
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(0x21D4, 0x21D4),
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(0x21E7, 0x21E7),
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(0x2200, 0x2200),
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(0x2202, 0x2203),
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(0x2207, 0x2208),
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(0x220B, 0x220B),
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(0x220F, 0x220F),
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(0x2211, 0x2211),
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(0x2215, 0x2215),
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(0x221A, 0x221A),
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(0x221D, 0x2220),
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(0x2223, 0x2223),
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(0x2225, 0x2225),
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(0x2227, 0x222C),
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(0x222E, 0x222E),
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(0x2234, 0x2237),
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(0x223C, 0x223D),
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(0x2248, 0x2248),
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(0x224C, 0x224C),
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(0x2252, 0x2252),
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(0x2260, 0x2261),
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(0x2264, 0x2267),
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(0x226A, 0x226B),
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(0x226E, 0x226F),
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(0x2282, 0x2283),
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(0x2286, 0x2287),
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(0x2295, 0x2295),
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(0x2299, 0x2299),
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(0x22A5, 0x22A5),
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(0x22BF, 0x22BF),
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(0x2312, 0x2312),
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(0x2329, 0x232A),
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(0x2460, 0x24BF),
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(0x24D0, 0x24E9),
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(0x2500, 0x254B),
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(0x2550, 0x2574),
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(0x2580, 0x258F),
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(0x2592, 0x2595),
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(0x25A0, 0x25A1),
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(0x25A3, 0x25A9),
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(0x25B2, 0x25B3),
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(0x25B6, 0x25B7),
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(0x25BC, 0x25BD),
|
||
(0x25C0, 0x25C1),
|
||
(0x25C6, 0x25C8),
|
||
(0x25CB, 0x25CB),
|
||
(0x25CE, 0x25D1),
|
||
(0x25E2, 0x25E5),
|
||
(0x25EF, 0x25EF),
|
||
(0x2605, 0x2606),
|
||
(0x2609, 0x2609),
|
||
(0x260E, 0x260F),
|
||
(0x261C, 0x261C),
|
||
(0x261E, 0x261E),
|
||
(0x2640, 0x2640),
|
||
(0x2642, 0x2642),
|
||
(0x2660, 0x2661),
|
||
(0x2663, 0x2665),
|
||
(0x2667, 0x266A),
|
||
(0x266C, 0x266D),
|
||
(0x266F, 0x266F),
|
||
(0x273D, 0x273D),
|
||
(0x3008, 0x300B),
|
||
(0x3014, 0x3015),
|
||
(0x3018, 0x301B),
|
||
(0xFFFD, 0xFFFD),
|
||
];
|
||
|
||
/* binary search in table of non-spacing characters */
|
||
if bisearch(ucs, ambiguous) {
|
||
return Some(2);
|
||
}
|
||
|
||
return wcwidth(ucs);
|
||
}
|
||
|
||
fn wcswidth_cjk(mut pwcs: WChar, mut n: WChar) -> Option<usize> {
|
||
let mut width = 0;
|
||
|
||
while (pwcs > 0) && n > 0 {
|
||
if let Some(w) = wcwidth_cjk(pwcs) {
|
||
width += w;
|
||
} else {
|
||
return None;
|
||
}
|
||
|
||
pwcs += 1;
|
||
n -= 1;
|
||
}
|
||
|
||
return Some(width);
|
||
}
|