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 ecow::EcoString;
use crate::diag::{bail, StrResult};
/// A symbol, possibly with variants.
#[derive(Clone, Eq, PartialEq, Hash)]
pub struct Symbol(Repr);
/// The internal representation.
#[derive(Clone, Eq, PartialEq, Hash)]
enum Repr {
Single(char),
Const(&'static [(&'static str, char)]),
Multi(Arc<(List, EcoString)>),
}
/// A collection of symbols.
#[derive(Clone, Eq, PartialEq, Hash)]
enum List {
Static(&'static [(&'static str, char)]),
Runtime(Box<[(EcoString, char)]>),
}
impl Symbol {
/// Create a new symbol from a single character.
pub const fn new(c: char) -> Self {
Self(Repr::Single(c))
}
/// Create a symbol with a static variant list.
#[track_caller]
pub const fn list(list: &'static [(&'static str, char)]) -> Self {
debug_assert!(!list.is_empty());
Self(Repr::Const(list))
}
/// Create a symbol with a runtime variant list.
#[track_caller]
pub fn runtime(list: Box<[(EcoString, char)]>) -> Self {
debug_assert!(!list.is_empty());
Self(Repr::Multi(Arc::new((List::Runtime(list), EcoString::new()))))
}
/// Get the symbol's text.
pub fn get(&self) -> char {
match &self.0 {
Repr::Single(c) => *c,
Repr::Const(_) => find(self.variants(), "").unwrap(),
Repr::Multi(arc) => find(self.variants(), &arc.1).unwrap(),
}
}
/// Apply a modifier to the symbol.
pub fn modified(mut self, modifier: &str) -> StrResult<Self> {
if let Repr::Const(list) = self.0 {
self.0 = Repr::Multi(Arc::new((List::Static(list), EcoString::new())));
}
if let Repr::Multi(arc) = &mut self.0 {
let (list, modifiers) = Arc::make_mut(arc);
if !modifiers.is_empty() {
modifiers.push('.');
}
modifiers.push_str(modifier);
if find(list.variants(), modifiers).is_some() {
return Ok(self);
}
}
bail!("unknown symbol modifier")
}
/// The characters that are covered by this symbol.
pub fn variants(&self) -> impl Iterator<Item = (&str, char)> {
match &self.0 {
Repr::Single(c) => Variants::Single(Some(*c).into_iter()),
Repr::Const(list) => Variants::Static(list.iter()),
Repr::Multi(arc) => arc.0.variants(),
}
}
/// Possible modifiers.
pub fn modifiers(&self) -> impl Iterator<Item = &str> + '_ {
let mut set = BTreeSet::new();
let modifiers = match &self.0 {
Repr::Multi(arc) => arc.1.as_str(),
_ => "",
};
for modifier in self.variants().flat_map(|(name, _)| name.split('.')) {
if !modifier.is_empty() && !contained(modifiers, modifier) {
set.insert(modifier);
}
}
set.into_iter()
}
/// Normalize an accent to a combining one.
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{20db}' => '\u{20db}',
'\u{20dc}' => '\u{20dc}',
'\u{030a}' | '∘' | '○' => '\u{030a}',
'\u{030b}' | '˝' => '\u{030b}',
'\u{030c}' | 'ˇ' => '\u{030c}',
'\u{20d6}' | '←' => '\u{20d6}',
'\u{20d7}' | '→' | '⟶' => '\u{20d7}',
_ => return None,
})
}
}
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())
}
}
impl List {
/// The characters that are covered by this list.
fn variants(&self) -> Variants<'_> {
match self {
List::Static(list) => Variants::Static(list.iter()),
List::Runtime(list) => Variants::Runtime(list.iter()),
}
}
}
/// 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)
}
|
