1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
use std::cmp::Reverse;
use std::collections::BTreeSet;
use std::fmt::{self, Debug, Display, Formatter, Write};
use std::sync::Arc;
use crate::diag::StrResult;
use crate::util::EcoString;
/// Define a list of symbols.
#[macro_export]
#[doc(hidden)]
macro_rules! __symbols {
($func:ident, $($name:ident: $value:tt),* $(,)?) => {
pub(super) fn $func(scope: &mut $crate::model::Scope) {
$(scope.define(stringify!($name), $crate::model::symbols!(@one $value));)*
}
};
(@one $c:literal) => { $crate::model::Symbol::new($c) };
(@one [$($first:literal $(: $second:literal)?),* $(,)?]) => {
$crate::model::Symbol::list(&[
$($crate::model::symbols!(@pair $first $(: $second)?)),*
])
};
(@pair $first:literal) => { ("", $first) };
(@pair $first:literal: $second:literal) => { ($first, $second) };
}
#[doc(inline)]
pub use crate::__symbols as symbols;
/// A symbol.
#[derive(Clone, Eq, PartialEq, Hash)]
pub struct Symbol {
repr: Repr,
modifiers: EcoString,
}
/// A collection of symbols.
#[derive(Clone, Eq, PartialEq, Hash)]
enum Repr {
Single(char),
Static(&'static [(&'static str, char)]),
Runtime(Arc<Vec<(EcoString, char)>>),
}
impl Symbol {
/// Create a new symbol from a single character.
pub fn new(c: char) -> Self {
Self { repr: Repr::Single(c), modifiers: EcoString::new() }
}
/// Create a symbol with a static variant list.
#[track_caller]
pub fn list(list: &'static [(&'static str, char)]) -> Self {
debug_assert!(!list.is_empty());
Self {
repr: Repr::Static(list),
modifiers: EcoString::new(),
}
}
/// Create a symbol with a runtime variant list.
#[track_caller]
pub fn runtime(list: Vec<(EcoString, char)>) -> Self {
debug_assert!(!list.is_empty());
Self {
repr: Repr::Runtime(Arc::new(list)),
modifiers: EcoString::new(),
}
}
/// Get the symbol's text.
pub fn get(&self) -> char {
match self.repr {
Repr::Single(c) => c,
_ => find(self.variants(), &self.modifiers).unwrap(),
}
}
/// Apply a modifier to the symbol.
pub fn modified(mut self, modifier: &str) -> StrResult<Self> {
if !self.modifiers.is_empty() {
self.modifiers.push('.');
}
self.modifiers.push_str(modifier);
if find(self.variants(), &self.modifiers).is_none() {
Err("unknown modifier")?
}
Ok(self)
}
/// The characters that are covered by this symbol.
pub fn variants(&self) -> impl Iterator<Item = (&str, char)> {
match &self.repr {
Repr::Single(c) => Variants::Single(Some(*c).into_iter()),
Repr::Static(list) => Variants::Static(list.iter()),
Repr::Runtime(list) => Variants::Runtime(list.iter()),
}
}
/// Possible modifiers.
pub fn modifiers(&self) -> impl Iterator<Item = &str> + '_ {
let mut set = BTreeSet::new();
for modifier in self.variants().flat_map(|(name, _)| name.split('.')) {
if !modifier.is_empty() && !contained(&self.modifiers, modifier) {
set.insert(modifier);
}
}
set.into_iter()
}
}
impl Debug for Symbol {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
f.write_char(self.get())
}
}
impl Display for Symbol {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
f.write_char(self.get())
}
}
/// Iterator over variants.
enum Variants<'a> {
Single(std::option::IntoIter<char>),
Static(std::slice::Iter<'static, (&'static str, char)>),
Runtime(std::slice::Iter<'a, (EcoString, char)>),
}
impl<'a> Iterator for Variants<'a> {
type Item = (&'a str, char);
fn next(&mut self) -> Option<Self::Item> {
match self {
Self::Single(iter) => Some(("", iter.next()?)),
Self::Static(list) => list.next().copied(),
Self::Runtime(list) => list.next().map(|(s, c)| (s.as_str(), *c)),
}
}
}
/// Find the best symbol from the list.
fn find<'a>(
variants: impl Iterator<Item = (&'a str, char)>,
modifiers: &str,
) -> Option<char> {
let mut best = None;
let mut best_score = None;
// Find the best table entry with this name.
'outer: for candidate in variants {
for modifier in parts(modifiers) {
if !contained(candidate.0, modifier) {
continue 'outer;
}
}
let mut matching = 0;
let mut total = 0;
for modifier in parts(candidate.0) {
if contained(modifiers, modifier) {
matching += 1;
}
total += 1;
}
let score = (matching, Reverse(total));
if best_score.map_or(true, |b| score > b) {
best = Some(candidate.1);
best_score = Some(score);
}
}
best
}
/// Split a modifier list into its parts.
fn parts(modifiers: &str) -> impl Iterator<Item = &str> {
modifiers.split('.').filter(|s| !s.is_empty())
}
/// Whether the modifier string contains the modifier `m`.
fn contained(modifiers: &str, m: &str) -> bool {
parts(modifiers).any(|part| part == m)
}
/// Normalize an accent to a combining one.
///
/// https://www.w3.org/TR/mathml-core/#combining-character-equivalences
pub fn combining_accent(c: char) -> Option<char> {
Some(match c {
'\u{0300}' | '`' => '\u{0300}',
'\u{0301}' | '´' => '\u{0301}',
'\u{0302}' | '^' | 'ˆ' => '\u{0302}',
'\u{0303}' | '~' | '∼' | '˜' => '\u{0303}',
'\u{0304}' | '¯' => '\u{0304}',
'\u{0305}' | '-' | '‾' | '−' => '\u{0305}',
'\u{0306}' | '˘' => '\u{0306}',
'\u{0307}' | '.' | '˙' | '⋅' => '\u{0307}',
'\u{0308}' | '¨' => '\u{0308}',
'\u{030a}' | '∘' | '○' => '\u{030a}',
'\u{030b}' | '˝' => '\u{030b}',
'\u{030c}' | 'ˇ' => '\u{030c}',
'\u{20d6}' | '←' => '\u{20d6}',
'\u{20d7}' | '→' | '⟶' => '\u{20d7}',
_ => return None,
})
}
|
