Function `take_while_m_n`

fn take_while_m_n<F, I, Error: ParseError<I>>(m: usize, n: usize, cond: F) -> impl FnMut(I) -> crate::internal::IResult<I, I, Error>
where
    I: Input,
    F: Fn(<I as Input>::Item) -> bool

Returns the longest (m <= len <= n) input slice that matches the predicate.

The parser will return the longest slice that matches the given predicate (a function that takes the input and returns a bool).

It will return an Err::Error((_, ErrorKind::TakeWhileMN)) if the pattern wasn't met or is out of range (m <= len <= n).

Example

# use nom::{Err, error::{Error, ErrorKind}, Needed, IResult};
use nom::bytes::complete::take_while_m_n;
use nom::AsChar;

fn short_alpha(s: &[u8]) -> IResult<&[u8], &[u8]> {
  take_while_m_n(3, 6, AsChar::is_alpha)(s)
}

assert_eq!(short_alpha(b"latin123"), Ok((&b"123"[..], &b"latin"[..])));
assert_eq!(short_alpha(b"lengthy"), Ok((&b"y"[..], &b"length"[..])));
assert_eq!(short_alpha(b"latin"), Ok((&b""[..], &b"latin"[..])));
assert_eq!(short_alpha(b"ed"), Err(Err::Error(Error::new(&b"ed"[..], ErrorKind::TakeWhileMN))));
assert_eq!(short_alpha(b"12345"), Err(Err::Error(Error::new(&b"12345"[..], ErrorKind::TakeWhileMN))));