fn advance_token(&mut self) -> Token {
        let first_char = self.eat().unwrap();
        let token_kind = match first_char {
            // Whitespace sequence.
            c if is_whitespace(c) => self.whitespace(),
            c if is_id_start(c) => self.ident(),

            // One-symbol tokens.
            '.' => Dot,

            _ => Unknown,
        };
        Token::new(token_kind, self.len_consumed())
    }
/// Parses a token from the input string.
Parses a token from the input string.
Parses a token from the input string .
fn advance_token(&mut self) -> Token {
        let first_char = self.eat().unwrap();
        let token_kind = match first_char {
            // Whitespace sequence.
            c if is_whitespace(c) => self.whitespace(),
            c if is_id_start(c) => self.ident(),
            // One-symbol tokens.
            '.' => Dot,
            _ => Unknown,
        };
        Token::new(token_kind, self.len_consumed())
    }
fn advance_token ( & mut self ) -> Token { let first_char = self . eat ( ) . unwrap ( ) ; let token_kind = match first_char { // Whitespace sequence. c if is_whitespace ( c ) => self . whitespace ( ) , c if is_id_start ( c ) => self . ident ( ) , // One-symbol tokens. '.' => Dot , _ => Unknown , } ; Token :: new ( token_kind , self . len_consumed ( ) ) }
Parses a token from the input string.
Parses a token from the input string .
&mut self
&mut self