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
|
mod event;
mod input;
use {
grammar,
lexer::Token,
parser_api::Parser,
parser_impl::{
event::{process, Event},
input::{InputPosition, ParserInput},
},
TextUnit,
};
use SyntaxKind::{self, EOF, TOMBSTONE};
pub(crate) trait Sink<'a> {
type Tree;
fn new(text: &'a str) -> Self;
fn leaf(&mut self, kind: SyntaxKind, len: TextUnit);
fn start_internal(&mut self, kind: SyntaxKind);
fn finish_internal(&mut self);
fn error(&mut self, err: String);
fn finish(self) -> Self::Tree;
}
/// Parse a sequence of tokens into the representative node tree
pub(crate) fn parse<'a, S: Sink<'a>>(text: &'a str, tokens: &[Token]) -> S::Tree {
let events = {
let input = input::ParserInput::new(text, tokens);
let parser_impl = ParserImpl::new(&input);
let mut parser_api = Parser(parser_impl);
grammar::file(&mut parser_api);
parser_api.0.into_events()
};
let mut sink = S::new(text);
process(&mut sink, tokens, events);
sink.finish()
}
/// Implementation details of `Parser`, extracted
/// to a separate struct in order not to pollute
/// the public API of the `Parser`.
pub(crate) struct ParserImpl<'t> {
inp: &'t ParserInput<'t>,
pos: InputPosition,
events: Vec<Event>,
}
impl<'t> ParserImpl<'t> {
pub(crate) fn new(inp: &'t ParserInput<'t>) -> ParserImpl<'t> {
ParserImpl {
inp,
pos: InputPosition::new(),
events: Vec::new(),
}
}
pub(crate) fn into_events(self) -> Vec<Event> {
assert_eq!(self.nth(0), EOF);
self.events
}
pub(super) fn nth(&self, n: u32) -> SyntaxKind {
self.inp.kind(self.pos + n)
}
pub(super) fn at_kw(&self, t: &str) -> bool {
self.inp.text(self.pos) == t
}
pub(super) fn start(&mut self) -> u32 {
let pos = self.events.len() as u32;
self.event(Event::Start {
kind: TOMBSTONE,
forward_parent: None,
});
pos
}
pub(super) fn bump(&mut self) {
let kind = self.nth(0);
if kind == EOF {
return;
}
self.do_bump(kind);
}
pub(super) fn bump_remap(&mut self, kind: SyntaxKind) {
if self.nth(0) == EOF {
// TODO: panic!?
return;
}
self.do_bump(kind);
}
fn do_bump(&mut self, kind: SyntaxKind) {
self.pos += 1;
self.event(Event::Token {
kind,
n_raw_tokens: 1,
});
}
pub(super) fn error(&mut self, msg: String) {
self.event(Event::Error { msg })
}
pub(super) fn complete(&mut self, pos: u32, kind: SyntaxKind) {
match self.events[pos as usize] {
Event::Start {
kind: ref mut slot, ..
} => {
*slot = kind;
}
_ => unreachable!(),
}
self.event(Event::Finish);
}
pub(super) fn abandon(&mut self, pos: u32) {
let idx = pos as usize;
if idx == self.events.len() - 1 {
match self.events.pop() {
Some(Event::Start {
kind: TOMBSTONE,
forward_parent: None,
}) => (),
_ => unreachable!(),
}
}
}
pub(super) fn precede(&mut self, pos: u32) -> u32 {
let new_pos = self.start();
match self.events[pos as usize] {
Event::Start {
ref mut forward_parent,
..
} => {
*forward_parent = Some(new_pos - pos);
}
_ => unreachable!(),
}
new_pos
}
fn event(&mut self, event: Event) {
self.events.push(event)
}
}
|
