fn next()

in smt2parser/src/lib.rs [105:141]

• 34 lines of code
• 6 McCabe index (conditional complexity)

    fn next(&mut self) -> Option<Result<T::Command, T::Error>> {
        let mut parser = parser::Parser::new((&mut self.visitor, &mut self.position));
        let mut unmatched_paren = 0;
        while let Some(token) = self.lexer.next() {
            match &token {
                parser::Token::LeftParen => unmatched_paren += 1,
                parser::Token::RightParen => {
                    if unmatched_paren > 0 {
                        unmatched_paren -= 1;
                    }
                }
                _ => (),
            }
            self.lexer.update_position(parser.extra_mut().1);
            if let Err(err) = parser.parse(token) {
                return Some(Err(err));
            }
            if unmatched_paren == 0 {
                return match parser.end_of_input() {
                    Ok((command, _)) => Some(Ok(command)),
                    Err(err) => Some(Err(err)),
                };
            }
        }
        if unmatched_paren > 0 {
            // We ran out of valid tokens in the middle of a command.
            let extra = parser.into_extra();
            Some(Err(extra.0.parsing_error(
                extra.1.clone(),
                "unexpected end of input".into(),
            )))
        } else {
            // There are no more valid tokens to parse.
            // TODO: report invalid tokens as an error.
            None
        }
    }