1 // Copyright 2019 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
4 //
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10
11 //! Lookups of unicode properties using minimal perfect hashing.
12
13 use crate::perfect_hash::mph_lookup;
14 use crate::tables::*;
15
16 /// Look up the canonical combining class for a codepoint.
17 ///
18 /// The value returned is as defined in the Unicode Character Database.
canonical_combining_class(c: char) -> u819 pub fn canonical_combining_class(c: char) -> u8 {
20 mph_lookup(
21 c.into(),
22 CANONICAL_COMBINING_CLASS_SALT,
23 CANONICAL_COMBINING_CLASS_KV,
24 u8_lookup_fk,
25 u8_lookup_fv,
26 0,
27 )
28 }
29
composition_table(c1: char, c2: char) -> Option<char>30 pub(crate) fn composition_table(c1: char, c2: char) -> Option<char> {
31 if c1 < '\u{10000}' && c2 < '\u{10000}' {
32 mph_lookup(
33 (c1 as u32) << 16 | (c2 as u32),
34 COMPOSITION_TABLE_SALT,
35 COMPOSITION_TABLE_KV,
36 pair_lookup_fk,
37 pair_lookup_fv_opt,
38 None,
39 )
40 } else {
41 composition_table_astral(c1, c2)
42 }
43 }
44
canonical_fully_decomposed(c: char) -> Option<&'static [char]>45 pub(crate) fn canonical_fully_decomposed(c: char) -> Option<&'static [char]> {
46 mph_lookup(
47 c.into(),
48 CANONICAL_DECOMPOSED_SALT,
49 CANONICAL_DECOMPOSED_KV,
50 pair_lookup_fk,
51 pair_lookup_fv_opt,
52 None,
53 )
54 .map(|(start, len)| &CANONICAL_DECOMPOSED_CHARS[start as usize..][..len as usize])
55 }
56
compatibility_fully_decomposed(c: char) -> Option<&'static [char]>57 pub(crate) fn compatibility_fully_decomposed(c: char) -> Option<&'static [char]> {
58 mph_lookup(
59 c.into(),
60 COMPATIBILITY_DECOMPOSED_SALT,
61 COMPATIBILITY_DECOMPOSED_KV,
62 pair_lookup_fk,
63 pair_lookup_fv_opt,
64 None,
65 )
66 .map(|(start, len)| &COMPATIBILITY_DECOMPOSED_CHARS[start as usize..][..len as usize])
67 }
68
cjk_compat_variants_fully_decomposed(c: char) -> Option<&'static [char]>69 pub(crate) fn cjk_compat_variants_fully_decomposed(c: char) -> Option<&'static [char]> {
70 mph_lookup(
71 c.into(),
72 CJK_COMPAT_VARIANTS_DECOMPOSED_SALT,
73 CJK_COMPAT_VARIANTS_DECOMPOSED_KV,
74 pair_lookup_fk,
75 pair_lookup_fv_opt,
76 None,
77 )
78 .map(|(start, len)| &CJK_COMPAT_VARIANTS_DECOMPOSED_CHARS[start as usize..][..len as usize])
79 }
80
81 /// Return whether the given character is a combining mark (`General_Category=Mark`)
is_combining_mark(c: char) -> bool82 pub fn is_combining_mark(c: char) -> bool {
83 mph_lookup(
84 c.into(),
85 COMBINING_MARK_SALT,
86 COMBINING_MARK_KV,
87 bool_lookup_fk,
88 bool_lookup_fv,
89 false,
90 )
91 }
92
stream_safe_trailing_nonstarters(c: char) -> usize93 pub fn stream_safe_trailing_nonstarters(c: char) -> usize {
94 mph_lookup(
95 c.into(),
96 TRAILING_NONSTARTERS_SALT,
97 TRAILING_NONSTARTERS_KV,
98 u8_lookup_fk,
99 u8_lookup_fv,
100 0,
101 ) as usize
102 }
103
104 /// Extract the key in a 24 bit key and 8 bit value packed in a u32.
105 #[inline]
u8_lookup_fk(kv: u32) -> u32106 fn u8_lookup_fk(kv: u32) -> u32 {
107 kv >> 8
108 }
109
110 /// Extract the value in a 24 bit key and 8 bit value packed in a u32.
111 #[inline]
u8_lookup_fv(kv: u32) -> u8112 fn u8_lookup_fv(kv: u32) -> u8 {
113 (kv & 0xff) as u8
114 }
115
116 /// Extract the key for a boolean lookup.
117 #[inline]
bool_lookup_fk(kv: u32) -> u32118 fn bool_lookup_fk(kv: u32) -> u32 {
119 kv
120 }
121
122 /// Extract the value for a boolean lookup.
123 #[inline]
bool_lookup_fv(_kv: u32) -> bool124 fn bool_lookup_fv(_kv: u32) -> bool {
125 true
126 }
127
128 /// Extract the key in a pair.
129 #[inline]
pair_lookup_fk<T>(kv: (u32, T)) -> u32130 fn pair_lookup_fk<T>(kv: (u32, T)) -> u32 {
131 kv.0
132 }
133
134 /// Extract the value in a pair, returning an option.
135 #[inline]
pair_lookup_fv_opt<T>(kv: (u32, T)) -> Option<T>136 fn pair_lookup_fv_opt<T>(kv: (u32, T)) -> Option<T> {
137 Some(kv.1)
138 }
139