use crate::digit_table::*;

use core::ptr;

#[cfg_attr(feature = "no-panic", inline)]

pub unsafe fn write_exponent3(mut k: isize, mut result: *mut u8) -> usize {

    let sign = k < 0;

    if sign {

        *result = b'-';

        result = result.offset(1);

        k = -k;

    }

    debug_assert!(k < 1000);

    if k >= 100 {

        *result = b'0' + (k / 100) as u8;

        k %= 100;

        let d = DIGIT_TABLE.as_ptr().offset(k * 2);

        ptr::copy_nonoverlapping(d, result.offset(1), 2);

        sign as usize + 3

    } else if k >= 10 {

        let d = DIGIT_TABLE.as_ptr().offset(k * 2);

        ptr::copy_nonoverlapping(d, result, 2);

        sign as usize + 2

    } else {

        *result = b'0' + k as u8;

        sign as usize + 1

    }

}

#[cfg_attr(feature = "no-panic", inline)]

pub unsafe fn write_exponent2(mut k: isize, mut result: *mut u8) -> usize {

    let sign = k < 0;

    if sign {

        *result = b'-';

        result = result.offset(1);

        k = -k;

    }

    debug_assert!(k < 100);

    if k >= 10 {

        let d = DIGIT_TABLE.as_ptr().offset(k * 2);

        ptr::copy_nonoverlapping(d, result, 2);

        sign as usize + 2

    } else {

        *result = b'0' + k as u8;

        sign as usize + 1

    }

}