Function nom::bytes::complete::take_while1

pub fn take_while1<F, Input, Error: ParseError<Input>>(
    cond: F
) -> impl Fn(Input) -> IResult<Input, Input, Error>
where
    Input: InputTakeAtPosition,
    F: Fn(<Input as InputTakeAtPosition>::Item) -> bool,

Returns the longest (atleast 1) 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(Err::Error((_, ErrorKind::TakeWhile1))) if the pattern wasn’t met

Example

use nom::bytes::complete::take_while1;
use nom::character::is_alphabetic;

fn alpha(s: &[u8]) -> IResult<&[u8], &[u8]> {
  take_while1(is_alphabetic)(s)
}

assert_eq!(alpha(b"latin123"), Ok((&b"123"[..], &b"latin"[..])));
assert_eq!(alpha(b"latin"), Ok((&b""[..], &b"latin"[..])));
assert_eq!(alpha(b"12345"), Err(Err::Error((&b"12345"[..], ErrorKind::TakeWhile1))));