parser_combinators::combinator

Function not_followed_by

Source 
pub fn not_followed_by<P>(parser: P) -> NotFollowedBy<P>
where
    P: Parser,
    <P as Parser>::Output: Display,
Expand description

Succeeds only if parser fails. Never consumes any input.

let result = string("let")
    .skip(not_followed_by(alpha_num()))
    .parse("letx")
    .map(|x| x.0);
assert!(result.is_err());