pub fn take_while<F, Input, Error: ParseError<Input>>(
cond: F
) -> impl Fn(Input) -> IResult<Input, Input, Error> where
Input: InputTakeAtPosition,
F: Fn(<Input as InputTakeAtPosition>::Item) -> bool,
Expand description
Returns the longest input slice (if any) 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).
Streaming Specific
Streaming version will return a Err::Incomplete(Needed::new(1))
if the pattern reaches the end of the input.
Example
use nom::bytes::streaming::take_while;
use nom::character::is_alphabetic;
fn alpha(s: &[u8]) -> IResult<&[u8], &[u8]> {
take_while(is_alphabetic)(s)
}
assert_eq!(alpha(b"latin123"), Ok((&b"123"[..], &b"latin"[..])));
assert_eq!(alpha(b"12345"), Ok((&b"12345"[..], &b""[..])));
assert_eq!(alpha(b"latin"), Err(Err::Incomplete(Needed::new(1))));
assert_eq!(alpha(b""), Err(Err::Incomplete(Needed::new(1))));