Function eof

pub fn eof<I: InputLength + Clone, E: ParseError<I>>(
    input: I,
) -> IResult<I, I, E>

returns its input if it is at the end of input data

When we’re at the end of the data, this combinator will succeed

let parser = eof;
assert_eq!(parser("abc"), Err(Err::Error(("abc", ErrorKind::Eof))));
assert_eq!(parser(""), Ok(("", "")));