74 lines
1.4 KiB
Rust
74 lines
1.4 KiB
Rust
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use num::Rational64;
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use super::Int;
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use crate::prelude::*;
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pub type Ratio = num::BigRational;
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impl From<Int> for Ratio {
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fn from(value: Int) -> Self {
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Ratio::from_integer(value.into())
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}
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}
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impl From<&Int> for Ratio {
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fn from(value: &Int) -> Self {
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Ratio::from_integer(value.to_owned().into())
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}
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}
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pub trait RatioExt: Sized {
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fn div_euclid(&self, n: &Self) -> Self;
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fn rem_euclid(&self, n: &Self) -> Self;
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fn to_f64_uc(&self) -> f64;
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fn approximate_float(x: f64) -> Option<Self>;
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}
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impl RatioExt for Ratio {
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#[inline]
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fn div_euclid(&self, n: &Self) -> Ratio {
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let (n_abs, n_sgn) = (n.abs(), n.signum());
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(self / n_abs).floor() * n_sgn
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}
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#[inline]
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fn rem_euclid(&self, n: &Self) -> Ratio {
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ToPrimitive::to_f64(self);
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let n_abs = n.abs();
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self - (self / &n_abs).floor() * &n_abs
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}
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#[inline]
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fn to_f64_uc(&self) -> f64 {
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if let Some(f) = self.to_f64() {
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f
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} else if self.is_negative() {
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f64::NEG_INFINITY
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} else {
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f64::INFINITY
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}
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}
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fn approximate_float(x: f64) -> Option<Self> {
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match Rational64::approximate_float(x) {
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Some(r) => {
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let r = Ratio::new((*r.numer()).into(), (*r.denom()).into());
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Some(r)
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}
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None => {
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let mut y = x;
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if y.abs() < 1.0 {
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y = 1.0 / y;
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}
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let i = Int::from_f64(y)?;
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let r = Ratio::from_integer(i.into());
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if x.abs() < 1.0 {
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Some(r.recip())
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} else {
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Some(r)
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}
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}
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}
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}
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}
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