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 }
55
compatibility_fully_decomposed(c: char) -> Option<&'static [char]>56 pub(crate) fn compatibility_fully_decomposed(c: char) -> Option<&'static [char]> {
57 mph_lookup(
58 c.into(),
59 COMPATIBILITY_DECOMPOSED_SALT,
60 COMPATIBILITY_DECOMPOSED_KV,
61 pair_lookup_fk,
62 pair_lookup_fv_opt,
63 None,
64 )
65 }
66
67 /// Return whether the given character is a combining mark (`General_Category=Mark`)
is_combining_mark(c: char) -> bool68 pub fn is_combining_mark(c: char) -> bool {
69 mph_lookup(
70 c.into(),
71 COMBINING_MARK_SALT,
72 COMBINING_MARK_KV,
73 bool_lookup_fk,
74 bool_lookup_fv,
75 false,
76 )
77 }
78
stream_safe_trailing_nonstarters(c: char) -> usize79 pub fn stream_safe_trailing_nonstarters(c: char) -> usize {
80 mph_lookup(
81 c.into(),
82 TRAILING_NONSTARTERS_SALT,
83 TRAILING_NONSTARTERS_KV,
84 u8_lookup_fk,
85 u8_lookup_fv,
86 0,
87 ) as usize
88 }
89
90 /// Extract the key in a 24 bit key and 8 bit value packed in a u32.
91 #[inline]
u8_lookup_fk(kv: u32) -> u3292 fn u8_lookup_fk(kv: u32) -> u32 {
93 kv >> 8
94 }
95
96 /// Extract the value in a 24 bit key and 8 bit value packed in a u32.
97 #[inline]
u8_lookup_fv(kv: u32) -> u898 fn u8_lookup_fv(kv: u32) -> u8 {
99 (kv & 0xff) as u8
100 }
101
102 /// Extract the key for a boolean lookup.
103 #[inline]
bool_lookup_fk(kv: u32) -> u32104 fn bool_lookup_fk(kv: u32) -> u32 {
105 kv
106 }
107
108 /// Extract the value for a boolean lookup.
109 #[inline]
bool_lookup_fv(_kv: u32) -> bool110 fn bool_lookup_fv(_kv: u32) -> bool {
111 true
112 }
113
114 /// Extract the key in a pair.
115 #[inline]
pair_lookup_fk<T>(kv: (u32, T)) -> u32116 fn pair_lookup_fk<T>(kv: (u32, T)) -> u32 {
117 kv.0
118 }
119
120 /// Extract the value in a pair, returning an option.
121 #[inline]
pair_lookup_fv_opt<T>(kv: (u32, T)) -> Option<T>122 fn pair_lookup_fv_opt<T>(kv: (u32, T)) -> Option<T> {
123 Some(kv.1)
124 }
125