Method consume_label

core/src/lexer.rs:602–634

Consumes the label definition at the current position.

(&mut self, first: CharSpan)

    /// Consumes the label definition at the current position.
    fn consume_label(&mut self, first: CharSpan) -> io::Result<TokenSpan> {
        let mut s = String::new();

        match self.input.peek() {
            Some(Ok(ch_span)) => match ch_span.ch {
                ch if ch.is_word() && !ch.is_numeric() => s.push(self.input.next().unwrap()?.ch),
                _ch => (),
            },
            Some(Err(_)) => return Err(self.input.next().unwrap().unwrap_err()),
            None => (),
        }
        if s.is_empty() {
            return Ok(TokenSpan::new(Token::Bad("Empty label name".to_owned()), first.pos, 1));
        }

        loop {
            match self.input.peek() {
                Some(Ok(ch_span)) => match ch_span.ch {
                    ch if ch.is_word() => s.push(self.input.next().unwrap()?.ch),
                    ch if ch.is_separator() => break,
                    ch => {
                        let msg = format!("Unexpected character in label: {}", ch);
                        return self.handle_bad_read(msg, first.pos);
                    }
                },
                Some(Err(_)) => return Err(self.input.next().unwrap().unwrap_err()),
                None => break,
            }
        }

        let token_len = s.len() + 1;
        Ok(TokenSpan::new(Token::Label(s), first.pos, token_len))
    }

    /// Consumes the remainder of the line and returns the token that was encountered at the end
    /// (which may be EOF or end of line).