# Function nom::multi::many_m_n

source · [−]

    pub fn many_m_n<I, O, E, F>(
        min: usize,
        max: usize,
        parse: F
    ) -> impl FnMut(I) -> IResult<I, Vec<O>, E> where
        I: Clone + InputLength,
        F: Parser<I, O, E>,
        E: ParseError<I>,

Expand description

Repeats the embedded parser `m..=n` times

This stops before `n` when the parser returns `Err::Error` and returns the results that were accumulated. To instead chain an error up, see `cut`.

## Arguments

- `m` The minimum number of iterations.
- `n` The maximum number of iterations.
- `f` The parser to apply.

Note: If the parser passed to `many1` accepts empty inputs (like `alpha0` or `digit0`), `many1` will return an error, to prevent going into an infinite loop.

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

    fn parser(s: &str) -> IResult<&str, Vec<&str>> {
      many_m_n(0, 2, tag("abc"))(s)
    }

    assert_eq!(parser("abcabc"), Ok(("", vec!["abc", "abc"])));
    assert_eq!(parser("abc123"), Ok(("123", vec!["abc"])));
    assert_eq!(parser("123123"), Ok(("123123", vec![])));
    assert_eq!(parser(""), Ok(("", vec![])));
    assert_eq!(parser("abcabcabc"), Ok(("abc", vec!["abc", "abc"])));