Function take

pub fn take<C, Input, Error: ParseError<Input>>(
    count: C,
) -> impl Fn(Input) -> IResult<Input, Input, Error>
where
    Input: InputIter + InputTake,
    C: ToUsize,

Returns an input slice containing the first N input elements (Input[..N]).

It will return Err(Err::Error((_, ErrorKind::Eof))) if the input is shorter than the argument.

Example

use nom::bytes::complete::take;

fn take6(s: &str) -> IResult<&str, &str> {
  take(6usize)(s)
}

assert_eq!(take6("1234567"), Ok(("7", "123456")));
assert_eq!(take6("things"), Ok(("", "things")));
assert_eq!(take6("short"), Err(Err::Error(Error::new("short", ErrorKind::Eof))));
assert_eq!(take6(""), Err(Err::Error(Error::new("", ErrorKind::Eof))));

The units that are taken will depend on the input type. For example, for a &str it will take a number of char’s, whereas for a &[u8] it will take that many u8’s:

use nom::error::Error;
use nom::bytes::complete::take;

assert_eq!(take::<_, _, Error<_>>(1usize)("💙"), Ok(("", "💙")));
assert_eq!(take::<_, _, Error<_>>(1usize)("💙".as_bytes()), Ok((b"\x9F\x92\x99".as_ref(), b"\xF0".as_ref())));