1 | #[cfg (feature = "parsing" )] |
2 | use crate::buffer::Cursor; |
3 | #[cfg (feature = "parsing" )] |
4 | use crate::lookahead; |
5 | #[cfg (feature = "parsing" )] |
6 | use crate::parse::{Parse, ParseStream, Result}; |
7 | #[cfg (feature = "parsing" )] |
8 | use crate::token::Token; |
9 | |
10 | pub use proc_macro2::Ident; |
11 | |
12 | #[cfg (feature = "parsing" )] |
13 | #[doc (hidden)] |
14 | #[allow (non_snake_case)] |
15 | pub fn Ident(marker: lookahead::TokenMarker) -> Ident { |
16 | match marker {} |
17 | } |
18 | |
19 | #[cfg (feature = "parsing" )] |
20 | fn accept_as_ident(ident: &Ident) -> bool { |
21 | match ident.to_string().as_str() { |
22 | "_" | |
23 | // Based on https://doc.rust-lang.org/grammar.html#keywords |
24 | // and https://github.com/rust-lang/rfcs/blob/master/text/2421-unreservations-2018.md |
25 | // and https://github.com/rust-lang/rfcs/blob/master/text/2420-unreserve-proc.md |
26 | "abstract" | "as" | "become" | "box" | "break" | "const" | "continue" | |
27 | "crate" | "do" | "else" | "enum" | "extern" | "false" | "final" | "fn" | |
28 | "for" | "if" | "impl" | "in" | "let" | "loop" | "macro" | "match" | |
29 | "mod" | "move" | "mut" | "override" | "priv" | "pub" | "ref" | |
30 | "return" | "Self" | "self" | "static" | "struct" | "super" | "trait" | |
31 | "true" | "type" | "typeof" | "unsafe" | "unsized" | "use" | "virtual" | |
32 | "where" | "while" | "yield" => false, |
33 | _ => true, |
34 | } |
35 | } |
36 | |
37 | #[cfg (feature = "parsing" )] |
38 | #[cfg_attr (doc_cfg, doc(cfg(feature = "parsing" )))] |
39 | impl Parse for Ident { |
40 | fn parse(input: ParseStream) -> Result<Self> { |
41 | input.step(|cursor: StepCursor<'_, '_>| { |
42 | if let Some((ident: Ident, rest: Cursor<'_>)) = cursor.ident() { |
43 | if accept_as_ident(&ident) { |
44 | return Ok((ident, rest)); |
45 | } |
46 | } |
47 | Err(cursor.error(message:"expected identifier" )) |
48 | }) |
49 | } |
50 | } |
51 | |
52 | #[cfg (feature = "parsing" )] |
53 | impl Token for Ident { |
54 | fn peek(cursor: Cursor) -> bool { |
55 | if let Some((ident: Ident, _rest: Cursor<'_>)) = cursor.ident() { |
56 | accept_as_ident(&ident) |
57 | } else { |
58 | false |
59 | } |
60 | } |
61 | |
62 | fn display() -> &'static str { |
63 | "identifier" |
64 | } |
65 | } |
66 | |
67 | macro_rules! ident_from_token { |
68 | ($token:ident) => { |
69 | impl From<Token![$token]> for Ident { |
70 | fn from(token: Token![$token]) -> Ident { |
71 | Ident::new(stringify!($token), token.span) |
72 | } |
73 | } |
74 | }; |
75 | } |
76 | |
77 | ident_from_token!(self); |
78 | ident_from_token!(Self); |
79 | ident_from_token!(super); |
80 | ident_from_token!(crate); |
81 | ident_from_token!(extern); |
82 | |
83 | impl From<Token![_]> for Ident { |
84 | fn from(token: Token![_]) -> Ident { |
85 | Ident::new(string:"_" , token.span) |
86 | } |
87 | } |
88 | |
89 | pub fn xid_ok(symbol: &str) -> bool { |
90 | let mut chars: Chars<'_> = symbol.chars(); |
91 | let first: char = chars.next().unwrap(); |
92 | if !(first == '_' || unicode_ident::is_xid_start(ch:first)) { |
93 | return false; |
94 | } |
95 | for ch: char in chars { |
96 | if !unicode_ident::is_xid_continue(ch) { |
97 | return false; |
98 | } |
99 | } |
100 | true |
101 | } |
102 | |