Function eof

pub fn eof<I, E>(input: I) -> Result<(I, I), Err<E>>
where
    I: Input + Clone,
    E: ParseError<I>,

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(("", "")));