Function replace 

pub fn replace<'a, Toks, T, A, P, B>(
    p: P,
    value: B,
) -> impl Parser<'a, Toks, T, B>
where
    Toks: Tokens<T> + 'a,
    T: Clone + Debug,
    A: 'a,
    P: Parser<'a, Toks, T, A> + 'a,
    B: Clone + 'a,

Replaces the returned value of a successful parse with the given value.

When p successfully parses a value, it is replaced with another arbitrary value.

B is required to implement Clone because the parser can run multiple times and must be able to produce the same value each time.

Examples:

use bad_parsers::{Parser, token};

let p = token('a').replace(42);

assert_eq!(("", 42), p.parse("a").unwrap());
assert!(p.parse("b").is_err());