sci_notation.rs

pub fn int_from_bytes(x: &[u8]) -> i64 {
    from_utf8(x).unwrap().parse::<i64>().unwrap()
}

pub fn float_from_bytes(x: &[u8]) -> f64 {
    from_utf8(x).unwrap().parse::<f64>().unwrap()
}

named!(pub number<&[u8], i64>,
       do_parse!(opt!(multispace) >>
                 n: digit >>
                 opt!(complete!(multispace)) >>
                 (int_from_bytes(n))));

named!(pub negative_number<&[u8], i64>,
       do_parse!(negative: opt!(tag!("-")) >>
                 n: digit >>
                 ({
                     let number = int_from_bytes(n);
                     match negative {
                         Some(_) => -number,
                         None => number
                     }
                 })));

named!(real_exponent<&[u8], ()>,
       complete!(do_parse!(tag_no_case!("e") >> negative_number >> ())));

named!(pub real<&[u8], f64>,
       do_parse!(n: recognize!(do_parse!(opt!(tag!("-")) >>
                                         alt_complete!(do_parse!(digit >> tag!(".") >> digit >> opt!(real_exponent) >> ())
                                                       | do_parse!(digit >> tag!(".") >> opt!(real_exponent) >> ())
                                                       | do_parse!(tag!(".") >> digit >> opt!(real_exponent) >> ())
                                                       | do_parse!(digit >> real_exponent >> ())
                                         ) >> ())) >>
                 (float_from_bytes(n))));