parse.rs

pub fn integer<'a>(bin: bool) -> impl Fn(&'a [u8]) -> IResult<&'a [u8], i32> {
    map(pair(
        cond(bin, be_i32),
        cond(!bin,  
        map_res(
            map_res(
                recognize(pair(opt(tag("-")), take_while(nom::character::is_digit))),
                std::str::from_utf8,
            ),
            |s| s.parse::<i32>(),
        )
    )), |(a,b)| a.or(b).unwrap())
}