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
|
use std::mem;
use ra_parser::{TreeSink, ParseError};
use crate::{
SmolStr, SyntaxError, TextUnit, TextRange, SyntaxTreeBuilder,
SyntaxKind::{self, *},
parsing::Token,
syntax_node::GreenNode,
};
/// Bridges the parser with our specific syntax tree representation.
///
/// `TextTreeSink` also handles attachment of trivia (whitespace) to nodes.
pub(crate) struct TextTreeSink<'a> {
text: &'a str,
tokens: &'a [Token],
text_pos: TextUnit,
token_pos: usize,
state: State,
inner: SyntaxTreeBuilder,
}
enum State {
PendingStart,
Normal,
PendingFinish,
}
impl<'a> TreeSink for TextTreeSink<'a> {
fn leaf(&mut self, kind: SyntaxKind, n_tokens: u8) {
match mem::replace(&mut self.state, State::Normal) {
State::PendingStart => unreachable!(),
State::PendingFinish => self.inner.finish_branch(),
State::Normal => (),
}
self.eat_trivias();
let n_tokens = n_tokens as usize;
let len = self.tokens[self.token_pos..self.token_pos + n_tokens]
.iter()
.map(|it| it.len)
.sum::<TextUnit>();
self.do_leaf(kind, len, n_tokens);
}
fn start_branch(&mut self, kind: SyntaxKind) {
match mem::replace(&mut self.state, State::Normal) {
State::PendingStart => {
self.inner.start_branch(kind);
// No need to attach trivias to previous node: there is no
// previous node.
return;
}
State::PendingFinish => self.inner.finish_branch(),
State::Normal => (),
}
let n_trivias =
self.tokens[self.token_pos..].iter().take_while(|it| it.kind.is_trivia()).count();
let leading_trivias = &self.tokens[self.token_pos..self.token_pos + n_trivias];
let mut trivia_end =
self.text_pos + leading_trivias.iter().map(|it| it.len).sum::<TextUnit>();
let n_attached_trivias = {
let leading_trivias = leading_trivias.iter().rev().map(|it| {
let next_end = trivia_end - it.len;
let range = TextRange::from_to(next_end, trivia_end);
trivia_end = next_end;
(it.kind, &self.text[range])
});
n_attached_trivias(kind, leading_trivias)
};
self.eat_n_trivias(n_trivias - n_attached_trivias);
self.inner.start_branch(kind);
self.eat_n_trivias(n_attached_trivias);
}
fn finish_branch(&mut self) {
match mem::replace(&mut self.state, State::PendingFinish) {
State::PendingStart => unreachable!(),
State::PendingFinish => self.inner.finish_branch(),
State::Normal => (),
}
}
fn error(&mut self, error: ParseError) {
self.inner.error(error, self.text_pos)
}
}
impl<'a> TextTreeSink<'a> {
pub(super) fn new(text: &'a str, tokens: &'a [Token]) -> TextTreeSink<'a> {
TextTreeSink {
text,
tokens,
text_pos: 0.into(),
token_pos: 0,
state: State::PendingStart,
inner: SyntaxTreeBuilder::default(),
}
}
pub(super) fn finish(mut self) -> (GreenNode, Vec<SyntaxError>) {
match mem::replace(&mut self.state, State::Normal) {
State::PendingFinish => {
self.eat_trivias();
self.inner.finish_branch()
}
State::PendingStart | State::Normal => unreachable!(),
}
self.inner.finish_raw()
}
fn eat_trivias(&mut self) {
while let Some(&token) = self.tokens.get(self.token_pos) {
if !token.kind.is_trivia() {
break;
}
self.do_leaf(token.kind, token.len, 1);
}
}
fn eat_n_trivias(&mut self, n: usize) {
for _ in 0..n {
let token = self.tokens[self.token_pos];
assert!(token.kind.is_trivia());
self.do_leaf(token.kind, token.len, 1);
}
}
fn do_leaf(&mut self, kind: SyntaxKind, len: TextUnit, n_tokens: usize) {
let range = TextRange::offset_len(self.text_pos, len);
let text: SmolStr = self.text[range].into();
self.text_pos += len;
self.token_pos += n_tokens;
self.inner.leaf(kind, text);
}
}
fn n_attached_trivias<'a>(
kind: SyntaxKind,
trivias: impl Iterator<Item = (SyntaxKind, &'a str)>,
) -> usize {
match kind {
CONST_DEF | TYPE_DEF | STRUCT_DEF | ENUM_DEF | ENUM_VARIANT | FN_DEF | TRAIT_DEF
| MODULE | NAMED_FIELD_DEF => {
let mut res = 0;
for (i, (kind, text)) in trivias.enumerate() {
match kind {
WHITESPACE => {
if text.contains("\n\n") {
break;
}
}
COMMENT => {
res = i + 1;
}
_ => (),
}
}
res
}
_ => 0,
}
}
|
