Function winnow::combinator::not
source · pub fn not<Input, Output, Error, ParseNext>(
parser: ParseNext
) -> impl Parser<Input, (), Error>
Expand description
Succeeds if the child parser returns an error.
Note: This does not advance the Stream
§Example
use winnow::combinator::not;
use winnow::ascii::alpha1;
let mut parser = not(alpha1);
assert_eq!(parser.parse_peek("123"), Ok(("123", ())));
assert_eq!(parser.parse_peek("abcd"), Err(ErrMode::Backtrack(InputError::new("abcd", ErrorKind::Not))));