burbomath 0.0.1

Burbokop's rust math library
Documentation 
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use crate::math::{Floor, One, Zero};
use core::ops::{Div, Mul, Rem, Sub};

#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};

#[derive(Debug, PartialEq, Eq, Hash, PartialOrd, Ord, Clone)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub struct Rational<N, D> {
    pub numerator: N,
    pub denominator: D,
}

impl<N, D> Rational<N, D> {
    pub fn new(numerator: N, denominator: D) -> Self {
        Self {
            numerator,
            denominator,
        }
    }
}

impl<N, D> From<N> for Rational<N, D>
where
    D: One,
{
    fn from(value: N) -> Self {
        Self {
            numerator: value,
            denominator: D::one(),
        }
    }
}

pub trait ApplyRationalPrecision<T> {
    fn apply_rational_precision(x: T) -> Self;
    fn precision() -> Self;
}

#[cfg(feature = "std")]
impl ApplyRationalPrecision<f32> for u32 {
    fn apply_rational_precision(x: f32) -> Self {
        f32::round(1000000000. * x) as Self
    }

    fn precision() -> Self {
        1000000000
    }
}

#[cfg(feature = "libm")]
impl ApplyRationalPrecision<f32> for u32 {
    fn apply_rational_precision(x: f32) -> Self {
        libm::roundf(1000000000. * x) as Self
    }

    fn precision() -> Self {
        1000000000
    }
}

impl<T> Rational<T, T> {
    pub fn from_float<F>(value: F) -> Self
    where
        T: ApplyRationalPrecision<F>
            + PartialOrd
            + Rem<Output = T>
            + Clone
            + Zero
            + Div<Output = T>,
        F: Floor<Output = F> + Clone + Sub<Output = F> + Mul<Output = F>,
    {
        let frac = value.clone() - value.floor();

        let frac_mul_precision: T = ApplyRationalPrecision::apply_rational_precision(frac);
        let precision: T = ApplyRationalPrecision::precision();

        let gcd = greatest_common_divisor(frac_mul_precision.clone(), precision.clone());

        let denominator = precision / gcd.clone();
        let numerator = frac_mul_precision / gcd;

        Self {
            numerator,
            denominator,
        }
    }
}

fn greatest_common_divisor<T>(a: T, b: T) -> T
where
    T: Zero + PartialOrd + Rem<Output = T> + Clone,
{
    if a == T::zero() {
        b
    } else if b == T::zero() {
        a
    } else if a < b {
        greatest_common_divisor(a.clone(), b % a)
    } else {
        greatest_common_divisor(b.clone(), a % b)
    }
}