pub fn fail<Input, Output, Error>(i: &mut Input) -> Result<Output, Error>where
Input: Stream,
Error: ParserError<Input>,
Expand description
A parser which always fails.
For example, it can be used as the last alternative in alt
to
control the error message given.
§Example
use winnow::combinator::fail;
fn parser<'i>(input: &mut &'i str) -> ModalResult<(), InputError<&'i str>> {
fail.parse_next(input)
}
assert_eq!(parser.parse_peek("string"), Err(ErrMode::Backtrack(InputError::at("string"))));