aboutsummaryrefslogtreecommitdiff
path: root/crates/libsyntax2/src/grammar/mod.rs
blob: 1acecac410b120df529933d40a74f4c56cba9091 (plain)
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
//! This is the actual "grammar" of the Rust language.
//!
//! Each function in this module and its children corresponds
//! to a production of the format grammar. Submodules roughly
//! correspond to different *areas* of the grammar. By convention,
//! each submodule starts with `use super::*` import and exports
//! "public" productions via `pub(super)`.
//!
//! See docs for `Parser` to learn about API, available to the grammar,
//! and see docs for `Event` to learn how this actually manages to
//! produce parse trees.
//!
//! Code in this module also contains inline tests, which start with
//! `// test name-of-the-test` comment and look like this:
//!
//! ```
//! // test function_with_zero_parameters
//! // fn foo() {}
//! ```
//!
//! After adding a new inline-test, run `cargo collect-tests` to extract
//! it as a standalone text-fixture into `tests/data/parser/inline`, and
//! run `cargo test` once to create the "gold" value.
mod attributes;
mod expressions;
mod items;
mod params;
mod paths;
mod patterns;
mod type_args;
mod type_params;
mod types;

use {
    parser_api::{Marker, CompletedMarker, Parser, TokenSet},
    SyntaxKind::{self, *},
};
pub(crate) use self::{
    expressions::block,
    items::named_field_def_list,
};

pub(crate) fn root(p: &mut Parser) {
    let m = p.start();
    p.eat(SHEBANG);
    items::mod_contents(p, false);
    m.complete(p, ROOT);
}


#[derive(Clone, Copy, PartialEq, Eq)]
enum BlockLike {
    Block,
    NotBlock,
}

impl BlockLike {
    fn is_block(self) -> bool { self == BlockLike::Block }
}

fn opt_visibility(p: &mut Parser) {
    match p.current() {
        PUB_KW => {
            let m = p.start();
            p.bump();
            if p.at(L_PAREN) {
                match p.nth(1) {
                    // test crate_visibility
                    // pub(crate) struct S;
                    // pub(self) struct S;
                    // pub(self) struct S;
                    // pub(self) struct S;
                    CRATE_KW | SELF_KW | SUPER_KW => {
                        p.bump();
                        p.bump();
                        p.expect(R_PAREN);
                    }
                    IN_KW => {
                        p.bump();
                        p.bump();
                        paths::use_path(p);
                        p.expect(R_PAREN);
                    }
                    _ => (),
                }
            }
            m.complete(p, VISIBILITY);
        }
        // test crate_keyword_vis
        // crate fn main() { }
        CRATE_KW => {
            let m = p.start();
            p.bump();
            m.complete(p, VISIBILITY);
        }
        _ => (),
    }
}

fn opt_alias(p: &mut Parser) {
    if p.at(AS_KW) {
        let m = p.start();
        p.bump();
        name(p);
        m.complete(p, ALIAS);
    }
}

fn abi(p: &mut Parser) {
    assert!(p.at(EXTERN_KW));
    let abi = p.start();
    p.bump();
    match p.current() {
        STRING | RAW_STRING => p.bump(),
        _ => (),
    }
    abi.complete(p, ABI);
}

fn opt_fn_ret_type(p: &mut Parser) -> bool {
    if p.at(THIN_ARROW) {
        let m = p.start();
        p.bump();
        types::type_(p);
        m.complete(p, RET_TYPE);
        true
    } else {
        false
    }
}

fn name(p: &mut Parser) {
    if p.at(IDENT) {
        let m = p.start();
        p.bump();
        m.complete(p, NAME);
    } else {
        p.err_and_bump("expected a name");
    }
}

fn name_ref(p: &mut Parser) {
    if p.at(IDENT) {
        let m = p.start();
        p.bump();
        m.complete(p, NAME_REF);
    } else {
        p.err_and_bump("expected identifier");
    }
}

fn error_block(p: &mut Parser, message: &str) {
    go(p, Some(message));
    fn go(p: &mut Parser, message: Option<&str>) {
        assert!(p.at(L_CURLY));
        let m = p.start();
        if let Some(message) = message {
            p.error(message);
        }
        p.bump();
        while !p.at(EOF) && !p.at(R_CURLY) {
            match p.current() {
                L_CURLY => go(p, None),
                _ => p.bump(),
            }
        }
        p.eat(R_CURLY);
        m.complete(p, ERROR);
    }
}