Function parse

pub fn parse<'a, E>(
    options: &ParseOptions,
) -> impl FnMut(&'a [u8]) -> IResult<&'a [u8], Problem, E>
where
    E: ParseError<&'a [u8]> + ContextError<&'a [u8]> + FromExternalError<&'a [u8], String>,

Parse a NNF file