Function chumsky::primitive::just

pub fn just<I: Clone + PartialEq, E>(x: I) -> Just<I, E>

A parser that accepts only the given token.

Examples

use chumsky::prelude::*;

let question = just::<_, Simple<char>>('?');

assert_eq!(question.parse("?"), Ok('?'));
assert!(question.parse("!").is_err());
// This works because parsers do not eagerly consume input, so the '!' is not parsed
assert_eq!(question.parse("?!"), Ok('?'));
// This fails because the parser expects an end to the input after the '?'
assert!(question.then(end()).parse("?!").is_err());