1 | #[cfg (feature = "parsing" )] |
2 | use crate::lookahead; |
3 | |
4 | pub use proc_macro2::Ident; |
5 | |
6 | #[cfg (feature = "parsing" )] |
7 | #[doc (hidden)] |
8 | #[allow (non_snake_case)] |
9 | pub fn Ident(marker: lookahead::TokenMarker) -> Ident { |
10 | match marker {} |
11 | } |
12 | |
13 | macro_rules! ident_from_token { |
14 | ($token:ident) => { |
15 | impl From<Token![$token]> for Ident { |
16 | fn from(token: Token![$token]) -> Ident { |
17 | Ident::new(stringify!($token), token.span) |
18 | } |
19 | } |
20 | }; |
21 | } |
22 | |
23 | ident_from_token!(self); |
24 | ident_from_token!(Self); |
25 | ident_from_token!(super); |
26 | ident_from_token!(crate); |
27 | ident_from_token!(extern); |
28 | |
29 | impl From<Token![_]> for Ident { |
30 | fn from(token: Token![_]) -> Ident { |
31 | Ident::new(string:"_" , token.span) |
32 | } |
33 | } |
34 | |
35 | pub(crate) fn xid_ok(symbol: &str) -> bool { |
36 | let mut chars: Chars<'_> = symbol.chars(); |
37 | let first: char = chars.next().unwrap(); |
38 | if !(first == '_' || unicode_ident::is_xid_start(ch:first)) { |
39 | return false; |
40 | } |
41 | for ch: char in chars { |
42 | if !unicode_ident::is_xid_continue(ch) { |
43 | return false; |
44 | } |
45 | } |
46 | true |
47 | } |
48 | |
49 | #[cfg (feature = "parsing" )] |
50 | mod parsing { |
51 | use crate::buffer::Cursor; |
52 | use crate::parse::{Parse, ParseStream, Result}; |
53 | use crate::token::Token; |
54 | use proc_macro2::Ident; |
55 | |
56 | fn accept_as_ident(ident: &Ident) -> bool { |
57 | match ident.to_string().as_str() { |
58 | "_" | |
59 | // Based on https://doc.rust-lang.org/1.65.0/reference/keywords.html |
60 | "abstract" | "as" | "async" | "await" | "become" | "box" | "break" | |
61 | "const" | "continue" | "crate" | "do" | "dyn" | "else" | "enum" | |
62 | "extern" | "false" | "final" | "fn" | "for" | "if" | "impl" | "in" | |
63 | "let" | "loop" | "macro" | "match" | "mod" | "move" | "mut" | |
64 | "override" | "priv" | "pub" | "ref" | "return" | "Self" | "self" | |
65 | "static" | "struct" | "super" | "trait" | "true" | "try" | "type" | |
66 | "typeof" | "unsafe" | "unsized" | "use" | "virtual" | "where" | |
67 | "while" | "yield" => false, |
68 | _ => true, |
69 | } |
70 | } |
71 | |
72 | #[cfg_attr (doc_cfg, doc(cfg(feature = "parsing" )))] |
73 | impl Parse for Ident { |
74 | fn parse(input: ParseStream) -> Result<Self> { |
75 | input.step(|cursor| { |
76 | if let Some((ident, rest)) = cursor.ident() { |
77 | if accept_as_ident(&ident) { |
78 | Ok((ident, rest)) |
79 | } else { |
80 | Err(cursor.error(format_args!( |
81 | "expected identifier, found keyword ` {}`" , |
82 | ident, |
83 | ))) |
84 | } |
85 | } else { |
86 | Err(cursor.error("expected identifier" )) |
87 | } |
88 | }) |
89 | } |
90 | } |
91 | |
92 | impl Token for Ident { |
93 | fn peek(cursor: Cursor) -> bool { |
94 | if let Some((ident, _rest)) = cursor.ident() { |
95 | accept_as_ident(&ident) |
96 | } else { |
97 | false |
98 | } |
99 | } |
100 | |
101 | fn display() -> &'static str { |
102 | "identifier" |
103 | } |
104 | } |
105 | } |
106 | |