Function nom::multi::many0_count

source · 
pub fn many0_count<I, O, E, F>(f: F) -> impl FnMut(I) -> IResult<I, usize, E>
where
    I: Clone + InputLength,
    F: Parser<I, O, E>,
    E: ParseError<I>,
Expand description

Repeats the embedded parser, counting the results

This stops on Err::Error. To instead chain an error up, see cut.

§Arguments

  • f The parser to apply.

Note: if the parser passed in accepts empty inputs (like alpha0 or digit0), many0 will return an error, to prevent going into an infinite loop

use nom::multi::many0_count;
use nom::bytes::complete::tag;

fn parser(s: &str) -> IResult<&str, usize> {
  many0_count(tag("abc"))(s)
}

assert_eq!(parser("abcabc"), Ok(("", 2)));
assert_eq!(parser("abc123"), Ok(("123", 1)));
assert_eq!(parser("123123"), Ok(("123123", 0)));
assert_eq!(parser(""), Ok(("", 0)));