vendor/unicode-bidi/src/char_data/mod.rs

   1 // Copyright 2015 The Servo Project Developers. See the
   2 // COPYRIGHT file at the top-level directory of this distribution.
   3 //
   4 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   5 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   7 // option. This file may not be copied, modified, or distributed
   8 // except according to those terms.
   9
  10 //! Accessor for `Bidi_Class` property from Unicode Character Database (UCD)
  11
  12 mod tables;
  13
  14 pub use self::tables::{BidiClass, UNICODE_VERSION};
  15
  16 use std::cmp::Ordering::{Equal, Less, Greater};
  17 use std::char;
  18
  19 use self::tables::bidi_class_table;
  20 use BidiClass::*;
  21
  22 /// Find the `BidiClass` of a single char.
  23 pub fn bidi_class(c: char) -> BidiClass {
  24     bsearch_range_value_table(c, bidi_class_table)
  25 }
  26
  27 pub fn is_rtl(bidi_class: BidiClass) -> bool {
  28     match bidi_class {
  29         RLE | RLO | RLI => true,
  30         _ => false,
  31     }
  32 }
  33
  34 fn bsearch_range_value_table(c: char, r: &'static [(char, char, BidiClass)]) -> BidiClass {
  35     match r.binary_search_by(|&(lo, hi, _)| if lo <= c && c <= hi {
  36         Equal
  37     } else if hi < c {
  38         Less
  39     } else {
  40         Greater
  41     }) {
  42         Ok(idx) => {
  43             let (_, _, cat) = r[idx];
  44             cat
  45         }
  46         // UCD/extracted/DerivedBidiClass.txt: "All code points not explicitly listed
  47         // for Bidi_Class have the value Left_To_Right (L)."
  48         Err(_) => L,
  49     }
  50 }
  51
  52 #[cfg(test)]
  53 mod tests {
  54     use super::*;
  55
  56     #[test]
  57     fn test_ascii() {
  58         assert_eq!(bidi_class('\u{0000}'), BN);
  59         assert_eq!(bidi_class('\u{0040}'), ON);
  60         assert_eq!(bidi_class('\u{0041}'), L);
  61         assert_eq!(bidi_class('\u{0062}'), L);
  62         assert_eq!(bidi_class('\u{007F}'), BN);
  63     }
  64
  65     #[test]
  66     fn test_bmp() {
  67         // Hebrew
  68         assert_eq!(bidi_class('\u{0590}'), R);
  69         assert_eq!(bidi_class('\u{05D0}'), R);
  70         assert_eq!(bidi_class('\u{05D1}'), R);
  71         assert_eq!(bidi_class('\u{05FF}'), R);
  72
  73         // Arabic
  74         assert_eq!(bidi_class('\u{0600}'), AN);
  75         assert_eq!(bidi_class('\u{0627}'), AL);
  76         assert_eq!(bidi_class('\u{07BF}'), AL);
  77
  78         // Default R + Arabic Extras
  79         assert_eq!(bidi_class('\u{07C0}'), R);
  80         assert_eq!(bidi_class('\u{085F}'), R);
  81         assert_eq!(bidi_class('\u{0860}'), AL);
  82         assert_eq!(bidi_class('\u{0870}'), R);
  83         assert_eq!(bidi_class('\u{089F}'), R);
  84         assert_eq!(bidi_class('\u{08A0}'), AL);
  85         assert_eq!(bidi_class('\u{089F}'), R);
  86         assert_eq!(bidi_class('\u{08FF}'), NSM);
  87
  88         // Default ET
  89         assert_eq!(bidi_class('\u{20A0}'), ET);
  90         assert_eq!(bidi_class('\u{20CF}'), ET);
  91
  92         // Arabic Presentation Forms
  93         assert_eq!(bidi_class('\u{FB1D}'), R);
  94         assert_eq!(bidi_class('\u{FB4F}'), R);
  95         assert_eq!(bidi_class('\u{FB50}'), AL);
  96         assert_eq!(bidi_class('\u{FDCF}'), AL);
  97         assert_eq!(bidi_class('\u{FDF0}'), AL);
  98         assert_eq!(bidi_class('\u{FDFF}'), AL);
  99         assert_eq!(bidi_class('\u{FE70}'), AL);
 100         assert_eq!(bidi_class('\u{FEFE}'), AL);
 101         assert_eq!(bidi_class('\u{FEFF}'), BN);
 102
 103         // noncharacters
 104         assert_eq!(bidi_class('\u{FDD0}'), L);
 105         assert_eq!(bidi_class('\u{FDD1}'), L);
 106         assert_eq!(bidi_class('\u{FDEE}'), L);
 107         assert_eq!(bidi_class('\u{FDEF}'), L);
 108         assert_eq!(bidi_class('\u{FFFE}'), L);
 109         assert_eq!(bidi_class('\u{FFFF}'), L);
 110     }
 111
 112     #[test]
 113     fn test_smp() {
 114         // Default AL + R
 115         assert_eq!(bidi_class('\u{10800}'), R);
 116         assert_eq!(bidi_class('\u{10FFF}'), R);
 117         assert_eq!(bidi_class('\u{1E800}'), R);
 118         assert_eq!(bidi_class('\u{1EDFF}'), R);
 119         assert_eq!(bidi_class('\u{1EE00}'), AL);
 120         assert_eq!(bidi_class('\u{1EEFF}'), AL);
 121         assert_eq!(bidi_class('\u{1EF00}'), R);
 122         assert_eq!(bidi_class('\u{1EFFF}'), R);
 123     }
 124
 125     #[test]
 126     fn test_unassigned_planes() {
 127         assert_eq!(bidi_class('\u{30000}'), L);
 128         assert_eq!(bidi_class('\u{40000}'), L);
 129         assert_eq!(bidi_class('\u{50000}'), L);
 130         assert_eq!(bidi_class('\u{60000}'), L);
 131         assert_eq!(bidi_class('\u{70000}'), L);
 132         assert_eq!(bidi_class('\u{80000}'), L);
 133         assert_eq!(bidi_class('\u{90000}'), L);
 134         assert_eq!(bidi_class('\u{a0000}'), L);
 135     }
 136 }