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
|
//! The Rust parser.
//!
//! The parser doesn't know about concrete representation of tokens and syntax
//! trees. Abstract `TokenSource` and `TreeSink` traits are used instead. As a
//! consequence, this crates does not contain a lexer.
//!
//! The `Parser` struct from the `parser` module is a cursor into the sequence
//! of tokens. Parsing routines use `Parser` to inspect current state and
//! advance the parsing.
//!
//! The actual parsing happens in the `grammar` module.
//!
//! Tests for this crate live in `ra_syntax` crate.
#[macro_use]
mod token_set;
#[macro_use]
mod syntax_kind;
mod event;
mod parser;
mod grammar;
pub(crate) use token_set::TokenSet;
pub use syntax_kind::SyntaxKind;
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct ParseError(pub String);
/// `TokenSource` abstracts the source of the tokens parser operates one.
///
/// Hopefully this will allow us to treat text and token trees in the same way!
pub trait TokenSource {
fn current(&self) -> Token;
/// Lookahead n token
fn lookahead_nth(&self, n: usize) -> Token;
/// bump cursor to next token
fn bump(&mut self);
/// Is the current token a specified keyword?
fn is_keyword(&self, kw: &str) -> bool;
}
/// `TokenCursor` abstracts the cursor of `TokenSource` operates one.
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub struct Token {
/// What is the current token?
pub kind: SyntaxKind,
/// Is the current token joined to the next one (`> >` vs `>>`).
pub is_jointed_to_next: bool,
}
/// `TreeSink` abstracts details of a particular syntax tree implementation.
pub trait TreeSink {
/// Adds new token to the current branch.
fn token(&mut self, kind: SyntaxKind, n_tokens: u8);
/// Start new branch and make it current.
fn start_node(&mut self, kind: SyntaxKind);
/// Finish current branch and restore previous
/// branch as current.
fn finish_node(&mut self);
fn error(&mut self, error: ParseError);
}
fn parse_from_tokens<F>(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink, f: F)
where
F: FnOnce(&mut parser::Parser),
{
let mut p = parser::Parser::new(token_source);
f(&mut p);
let events = p.finish();
event::process(tree_sink, events);
}
/// Parse given tokens into the given sink as a rust file.
pub fn parse(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::root);
}
/// Parse given tokens into the given sink as a path
pub fn parse_path(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::path);
}
/// Parse given tokens into the given sink as a expression
pub fn parse_expr(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::expr);
}
/// Parse given tokens into the given sink as a ty
pub fn parse_ty(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::type_);
}
/// Parse given tokens into the given sink as a pattern
pub fn parse_pat(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::pattern);
}
/// Parse given tokens into the given sink as a statement
pub fn parse_stmt(
token_source: &mut dyn TokenSource,
tree_sink: &mut dyn TreeSink,
with_semi: bool,
) {
parse_from_tokens(token_source, tree_sink, |p| grammar::stmt(p, with_semi));
}
/// Parse given tokens into the given sink as a block
pub fn parse_block(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::block);
}
pub fn parse_meta(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::meta_item);
}
/// Parse given tokens into the given sink as an item
pub fn parse_item(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::item);
}
/// Parse given tokens into the given sink as an visibility qualifier
pub fn parse_vis(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, |p| {
grammar::opt_visibility(p);
});
}
pub fn parse_macro_items(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::macro_items);
}
pub fn parse_macro_stmts(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
parse_from_tokens(token_source, tree_sink, grammar::macro_stmts);
}
/// A parsing function for a specific braced-block.
pub struct Reparser(fn(&mut parser::Parser));
impl Reparser {
/// If the node is a braced block, return the corresponding `Reparser`.
pub fn for_node(
node: SyntaxKind,
first_child: Option<SyntaxKind>,
parent: Option<SyntaxKind>,
) -> Option<Reparser> {
grammar::reparser(node, first_child, parent).map(Reparser)
}
/// Re-parse given tokens using this `Reparser`.
///
/// Tokens must start with `{`, end with `}` and form a valid brace
/// sequence.
pub fn parse(self, token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
let Reparser(r) = self;
let mut p = parser::Parser::new(token_source);
r(&mut p);
let events = p.finish();
event::process(tree_sink, events);
}
}
|
