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
13use crate::perfect_hash::mph_lookup;
14use 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.
19pub fn canonical_combining_class(c: char) -> u8 {
20 mph_lookup(
21 x:c.into(),
22 CANONICAL_COMBINING_CLASS_SALT,
23 CANONICAL_COMBINING_CLASS_KV,
24 u8_lookup_fk,
25 u8_lookup_fv,
26 default:0,
27 )
28}
29
30pub(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 fv:pair_lookup_fv_opt,
38 default:None,
39 )
40 } else {
41 composition_table_astral(c1, c2)
42 }
43}
44
45pub(crate) fn canonical_fully_decomposed(c: char) -> Option<&'static [char]> {
46 mph_lookupOption<(u16, u16)>(
47 x:c.into(),
48 CANONICAL_DECOMPOSED_SALT,
49 CANONICAL_DECOMPOSED_KV,
50 pair_lookup_fk,
51 fv:pair_lookup_fv_opt,
52 default:None,
53 )
54 .map(|(start: u16, len: u16)| &CANONICAL_DECOMPOSED_CHARS[start as usize..][..len as usize])
55}
56
57pub(crate) fn compatibility_fully_decomposed(c: char) -> Option<&'static [char]> {
58 mph_lookupOption<(u16, u16)>(
59 x:c.into(),
60 COMPATIBILITY_DECOMPOSED_SALT,
61 COMPATIBILITY_DECOMPOSED_KV,
62 pair_lookup_fk,
63 fv:pair_lookup_fv_opt,
64 default:None,
65 )
66 .map(|(start: u16, len: u16)| &COMPATIBILITY_DECOMPOSED_CHARS[start as usize..][..len as usize])
67}
68
69pub(crate) fn cjk_compat_variants_fully_decomposed(c: char) -> Option<&'static [char]> {
70 mph_lookupOption<(u16, u16)>(
71 x:c.into(),
72 CJK_COMPAT_VARIANTS_DECOMPOSED_SALT,
73 CJK_COMPAT_VARIANTS_DECOMPOSED_KV,
74 pair_lookup_fk,
75 fv:pair_lookup_fv_opt,
76 default:None,
77 )
78 .map(|(start: u16, len: u16)| &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`)
82pub fn is_combining_mark(c: char) -> bool {
83 mph_lookup(
84 x:c.into(),
85 COMBINING_MARK_SALT,
86 COMBINING_MARK_KV,
87 bool_lookup_fk,
88 bool_lookup_fv,
89 default:false,
90 )
91}
92
93pub fn stream_safe_trailing_nonstarters(c: char) -> usize {
94 mph_lookup(
95 x:c.into(),
96 TRAILING_NONSTARTERS_SALT,
97 TRAILING_NONSTARTERS_KV,
98 u8_lookup_fk,
99 u8_lookup_fv,
100 default: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]
106fn 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]
112fn u8_lookup_fv(kv: u32) -> u8 {
113 (kv & 0xff) as u8
114}
115
116/// Extract the key for a boolean lookup.
117#[inline]
118fn bool_lookup_fk(kv: u32) -> u32 {
119 kv
120}
121
122/// Extract the value for a boolean lookup.
123#[inline]
124fn bool_lookup_fv(_kv: u32) -> bool {
125 true
126}
127
128/// Extract the key in a pair.
129#[inline]
130fn 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]
136fn pair_lookup_fv_opt<T>(kv: (u32, T)) -> Option<T> {
137 Some(kv.1)
138}
139