mirror of https://github.com/boa-dev/boa.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
61 lines
1.7 KiB
61 lines
1.7 KiB
//! This module implements lexing for identifiers (foo, myvar, etc.) used in the JavaScript programing language. |
|
|
|
use super::{Cursor, Error, Tokenizer}; |
|
use crate::{ |
|
profiler::BoaProfiler, |
|
syntax::{ |
|
ast::{Position, Span}, |
|
lexer::{Token, TokenKind}, |
|
}, |
|
}; |
|
use std::io::Read; |
|
|
|
/// Identifier lexing. |
|
/// |
|
/// More information: |
|
/// - [ECMAScript reference][spec] |
|
/// - [MDN documentation][mdn] |
|
/// |
|
/// [spec]: https://tc39.es/ecma262/#prod-Identifier |
|
/// [mdn]: https://developer.mozilla.org/en-US/docs/Glossary/Identifier |
|
#[derive(Debug, Clone, Copy)] |
|
pub(super) struct Identifier { |
|
init: char, |
|
} |
|
|
|
impl Identifier { |
|
/// Creates a new identifier/keyword lexer. |
|
pub(super) fn new(init: char) -> Self { |
|
Self { init } |
|
} |
|
} |
|
|
|
impl<R> Tokenizer<R> for Identifier { |
|
fn lex(&mut self, cursor: &mut Cursor<R>, start_pos: Position) -> Result<Token, Error> |
|
where |
|
R: Read, |
|
{ |
|
let _timer = BoaProfiler::global().start_event("Identifier", "Lexing"); |
|
|
|
let mut buf = self.init.to_string(); |
|
|
|
cursor.take_while_pred(&mut buf, &|c: char| { |
|
c.is_alphabetic() || c.is_digit(10) || c == '_' |
|
})?; |
|
|
|
let tk = match buf.as_str() { |
|
"true" => TokenKind::BooleanLiteral(true), |
|
"false" => TokenKind::BooleanLiteral(false), |
|
"null" => TokenKind::NullLiteral, |
|
slice => { |
|
if let Ok(keyword) = slice.parse() { |
|
TokenKind::Keyword(keyword) |
|
} else { |
|
TokenKind::identifier(slice) |
|
} |
|
} |
|
}; |
|
|
|
Ok(Token::new(tk, Span::new(start_pos, cursor.pos()))) |
|
} |
|
}
|
|
|