extern crate serde;
extern crate zlo;

use zlo::Infinite;
use zlo::deserialize;
use zlo::serialize;

/// Per-part integer subtraction of two f32s used for diffing.
fn f32_diff(a: f32, b: f32) -> f32 {
    let sign_23 = |x| x | if (x & (1 << 22)) != 0 { 0xff800000 } else { 0 };
    let frac_mask = (1 << 23) - 1;
    let a = a.to_bits();
    let b = b.to_bits();
    let sign = ((a >> 31) != 0) ^ ((b >> 31) != 0);
    let exp  = ((a >> 23) as u8).wrapping_sub((b >> 23) as u8);
    let frac = sign_23(a & frac_mask)
        .wrapping_sub(sign_23(b & frac_mask))
        & frac_mask;
    let bits = ((sign as u32) << 31) | ((exp as u32) << 23) | frac;
    f32::from_bits(bits)
}

/// Per-part integer subtraction of two f64s used for diffing.
fn f64_diff(a: f64, b: f64) -> f64 {
    let sign_11 = |x| x | if (x & (1 << 10)) != 0 { 0xf800 } else { 0 };
    let sign_52 = |x| x | if (x & (1 << 51)) != 0 { 0xfff0000000000000 } else { 0 };
    let exp_mask = (1 << 11) - 1;
    let frac_mask = (1 << 52) - 1;
    let a = a.to_bits();
    let b = b.to_bits();
    let sign = ((a >> 63) != 0) ^ ((b >> 63) != 0);
    let exp  = sign_11((a >> 52) as u16 & exp_mask)
        .wrapping_sub(sign_11((b >> 52) as u16 & exp_mask))
        & exp_mask;
    let frac = sign_52(a & frac_mask)
        .wrapping_sub(sign_52(b & frac_mask))
        & frac_mask;
    let bits = ((sign as u64) << 63) | ((exp as u64) << 52) | frac;
    f64::from_bits(bits)
}

fn main() {
}