Method parse_next

examples/final.rs:71–78

(tokens: &mut Peekable<I>)

impl<'a> Element<'a> {
    fn parse_next<I: Iterator<Item = &'a str>>(tokens: &mut Peekable<I>) -> Option<Self> {
        tokens
            .next()
            .and_then(|next| match Self::parse_operator(next) {
                Some(operator) => Some(operator),
                None => Self::parse_cmd(next, tokens).map(Self::Cmd),
            })
    }

    fn parse_operator(token: &str) -> Option<Self> {
        match token {