OpenTally/src/numbers/rational_rug.rs

485 lines
13 KiB
Rust

/* OpenTally: Open-source election vote counting
* Copyright © 2021 Lee Yingtong Li (RunasSudo)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
use super::{Assign, Number};
use num_traits::{Num, One, Zero};
use rug::{self, ops::Pow, ops::PowAssign, rational::ParseRationalError};
use rug::Assign as RugAssign;
use std::cmp::{Ord, Ordering, PartialEq, PartialOrd};
use std::fmt;
use std::ops;
/// Rational number
#[derive(Clone, Debug, PartialEq, PartialOrd)]
pub struct Rational(rug::Rational);
impl Number for Rational {
fn new() -> Self { Self(rug::Rational::new()) }
fn describe() -> String { "--numbers rational".to_string() }
fn describe_opt() -> String { String::new() }
fn pow_assign(&mut self, exponent: i32) {
self.0.pow_assign(exponent);
}
fn floor_mut(&mut self, dps: usize) {
if dps == 0 {
self.0.floor_mut();
} else {
let factor = rug::Rational::from(10).pow(dps as u32);
self.0 *= &factor;
self.0.floor_mut();
self.0 /= factor;
}
}
fn ceil_mut(&mut self, dps: usize) {
if dps == 0 {
self.0.ceil_mut();
} else {
let factor = rug::Rational::from(10).pow(dps as u32);
self.0 *= &factor;
self.0.ceil_mut();
self.0 /= factor;
}
}
fn round_mut(&mut self, dps: usize) {
if dps == 0 {
self.0.round_mut();
} else {
// TODO: Streamline
let mut factor = Self::from(10);
factor.pow_assign(-(dps as i32));
factor /= Self::from(2);
*self = self.clone() + factor;
self.floor_mut(dps);
}
}
fn parse(s: &str) -> Self {
// Parse decimal
if s.contains('.') {
let (whole, decimal) = s.split_once('.').unwrap();
let whole = match rug::Rational::parse_radix(whole, 10) {
Ok(value) => rug::Rational::from(value),
Err(_) => panic!("Syntax Error"),
};
let decimal = match rug::Rational::parse_radix(decimal, 10) {
Ok(value) => rug::Rational::from(value),
Err(_) => panic!("Syntax Error"),
} / rug::Rational::from(10).pow(decimal.len() as u32);
if whole < rug::Rational::new() {
return Self(whole - decimal);
} else {
return Self(whole + decimal);
}
}
// Parse integer
if let Ok(value) = Self::from_str_radix(s, 10) {
return value;
} else {
panic!("Syntax Error");
}
}
}
#[test]
fn describe() {
// Never executed - just for the sake of code coverage
assert_eq!(Rational::describe(), "--numbers rational");
}
#[test]
fn rounding() {
let mut x = Rational::parse("55.550"); x.floor_mut(2); assert_eq!(x, Rational::parse("55.55"));
let mut x = Rational::parse("55.552"); x.floor_mut(2); assert_eq!(x, Rational::parse("55.55"));
let mut x = Rational::parse("55.555"); x.floor_mut(2); assert_eq!(x, Rational::parse("55.55"));
let mut x = Rational::parse("55.557"); x.floor_mut(2); assert_eq!(x, Rational::parse("55.55"));
let mut x = Rational::parse("55.550"); x.ceil_mut(2); assert_eq!(x, Rational::parse("55.55"));
let mut x = Rational::parse("55.552"); x.ceil_mut(2); assert_eq!(x, Rational::parse("55.56"));
let mut x = Rational::parse("55.555"); x.ceil_mut(2); assert_eq!(x, Rational::parse("55.56"));
let mut x = Rational::parse("55.557"); x.ceil_mut(2); assert_eq!(x, Rational::parse("55.56"));
let mut x = Rational::parse("55.550"); x.round_mut(2); assert_eq!(x, Rational::parse("55.55"));
let mut x = Rational::parse("55.552"); x.round_mut(2); assert_eq!(x, Rational::parse("55.55"));
let mut x = Rational::parse("55.555"); x.round_mut(2); assert_eq!(x, Rational::parse("55.56"));
let mut x = Rational::parse("55.557"); x.round_mut(2); assert_eq!(x, Rational::parse("55.56"));
}
impl Num for Rational {
type FromStrRadixErr = ParseRationalError;
fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
match rug::Rational::parse_radix(str, radix as i32) {
Ok(value) => Ok(Self(rug::Rational::from(value))),
Err(err) => Err(err)
}
}
}
impl Assign for Rational {
fn assign(&mut self, src: Self) { self.0.assign(src.0) }
}
impl Assign<&Self> for Rational {
fn assign(&mut self, src: &Self) { self.0.assign(&src.0) }
}
#[test]
fn assign() {
let a = Rational::parse("123.45");
let b = Rational::parse("678.90");
let mut x = a.clone(); x.assign(b.clone()); assert_eq!(x, b);
let mut x = a.clone(); x.assign(&b); assert_eq!(x, b);
}
impl From<usize> for Rational {
fn from(n: usize) -> Self { Self(rug::Rational::from(n)) }
}
impl fmt::Display for Rational {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if let Some(precision) = f.precision() {
if precision == 0 {
let result = rug::Integer::from((&self.0).round_ref()).to_string();
return f.write_str(&result);
} else {
let base = rug::Rational::from(10).pow(precision as u32);
let mut result = rug::Integer::from((&self.0 * base).abs().round_ref()).to_string();
let should_add_minus = (self.0 < 0) && result != "0";
// Add leading 0s
result = format!("{0:0>1$}", result, precision + 1);
// Add the decimal point
result.insert(result.len() - precision, '.');
// Add the sign
if should_add_minus {
result.insert(0, '-');
}
return f.write_str(&result);
}
} else {
return self.0.fmt(f);
}
}
}
#[test]
fn display_debug() {
let x = Rational::parse("123.4"); assert_eq!(format!("{}", x), "617/5");
let x = Rational::parse("123.4"); assert_eq!(format!("{:.2}", x), "123.40");
let x = Rational::parse("123.4"); assert_eq!(format!("{:?}", x), "Rational(617/5)");
}
impl One for Rational {
fn one() -> Self { Self(rug::Rational::from(1)) }
}
impl Zero for Rational {
fn zero() -> Self { Self::new() }
fn is_zero(&self) -> bool { self.0 == rug::Rational::new() }
}
impl Eq for Rational {}
impl Ord for Rational {
fn cmp(&self, other: &Self) -> Ordering { self.0.cmp(&other.0) }
}
impl ops::Neg for Rational {
type Output = Self;
fn neg(self) -> Self::Output { Self(-self.0) }
}
impl ops::Add for Rational {
type Output = Self;
fn add(self, rhs: Self) -> Self::Output { Self(self.0 + rhs.0) }
}
impl ops::Sub for Rational {
type Output = Self;
fn sub(self, rhs: Self) -> Self::Output { Self(self.0 - rhs.0) }
}
impl ops::Mul for Rational {
type Output = Self;
fn mul(self, rhs: Self) -> Self::Output { Self(self.0 * rhs.0) }
}
impl ops::Div for Rational {
type Output = Self;
fn div(self, rhs: Self) -> Self::Output {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
return Self(self.0 / rhs.0);
}
}
impl ops::Rem for Rational {
type Output = Self;
fn rem(self, rhs: Self) -> Self::Output {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
// TODO: Is there a cleaner way of implementing this?
let mut quotient = self.0 / &rhs.0;
quotient.rem_trunc_mut();
quotient *= rhs.0;
return Self(quotient);
}
}
#[test]
fn arith_owned_owned() {
let a = Rational::parse("123.45");
let b = Rational::parse("678.90");
assert_eq!(a.clone() + b.clone(), Rational::parse("802.35"));
assert_eq!(a.clone() - b.clone(), Rational::parse("-555.45"));
assert_eq!(a.clone() * b.clone(), Rational::parse("83810.205"));
assert_eq!((a.clone() / b.clone()) * b.clone(), a);
assert_eq!(b.clone() % a.clone(), Rational::parse("61.65"));
}
impl ops::Add<&Self> for Rational {
type Output = Self;
fn add(self, rhs: &Self) -> Self::Output { Self(self.0 + &rhs.0) }
}
impl ops::Sub<&Self> for Rational {
type Output = Self;
fn sub(self, rhs: &Self) -> Self::Output { Self(self.0 - &rhs.0) }
}
impl ops::Mul<&Self> for Rational {
type Output = Self;
fn mul(self, rhs: &Self) -> Self::Output { Self(self.0 * &rhs.0) }
}
impl ops::Div<&Self> for Rational {
type Output = Self;
fn div(self, rhs: &Self) -> Self::Output {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
return Self(self.0 / &rhs.0);
}
}
impl ops::Rem<&Self> for Rational {
type Output = Self;
fn rem(self, rhs: &Self) -> Self::Output {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
let mut quotient = self.0 / &rhs.0;
quotient.rem_trunc_mut();
quotient *= &rhs.0;
return Self(quotient);
}
}
#[test]
fn arith_owned_ref() {
let a = Rational::parse("123.45");
let b = Rational::parse("678.90");
assert_eq!(a.clone() + &b, Rational::parse("802.35"));
assert_eq!(a.clone() - &b, Rational::parse("-555.45"));
assert_eq!(a.clone() * &b, Rational::parse("83810.205"));
assert_eq!((a.clone() / &b) * &b, a);
assert_eq!(b.clone() % &a, Rational::parse("61.65"));
}
impl ops::AddAssign for Rational {
fn add_assign(&mut self, rhs: Self) { self.0 += rhs.0; }
}
impl ops::SubAssign for Rational {
fn sub_assign(&mut self, rhs: Self) { self.0 -= rhs.0; }
}
impl ops::MulAssign for Rational {
fn mul_assign(&mut self, rhs: Self) { self.0 *= rhs.0; }
}
impl ops::DivAssign for Rational {
fn div_assign(&mut self, rhs: Self) {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
self.0 /= rhs.0;
}
}
impl ops::RemAssign for Rational {
fn rem_assign(&mut self, rhs: Self) {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
self.0 /= &rhs.0;
self.0.rem_trunc_mut();
self.0 *= rhs.0;
}
}
#[test]
fn arithassign_owned() {
let a = Rational::parse("123.45");
let b = Rational::parse("678.90");
let mut x = a.clone(); x += b.clone(); assert_eq!(x, Rational::parse("802.35"));
let mut x = a.clone(); x -= b.clone(); assert_eq!(x, Rational::parse("-555.45"));
let mut x = a.clone(); x *= b.clone(); assert_eq!(x, Rational::parse("83810.205"));
let mut x = a.clone(); x /= b.clone(); x *= &b; assert_eq!(x, a);
let mut x = b.clone(); x %= a.clone(); assert_eq!(x, Rational::parse("61.65"));
}
impl ops::AddAssign<&Self> for Rational {
fn add_assign(&mut self, rhs: &Self) { self.0 += &rhs.0; }
}
impl ops::SubAssign<&Self> for Rational {
fn sub_assign(&mut self, rhs: &Self) { self.0 -= &rhs.0; }
}
impl ops::MulAssign<&Self> for Rational {
fn mul_assign(&mut self, rhs: &Self) { self.0 *= &rhs.0; }
}
impl ops::DivAssign<&Self> for Rational {
fn div_assign(&mut self, rhs: &Self) {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
self.0 /= &rhs.0;
}
}
impl ops::RemAssign<&Self> for Rational {
fn rem_assign(&mut self, rhs: &Self) {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
self.0 /= &rhs.0;
self.0.rem_trunc_mut();
self.0 *= &rhs.0;
}
}
#[test]
fn arithassign_ref() {
let a = Rational::parse("123.45");
let b = Rational::parse("678.90");
let mut x = a.clone(); x += &b; assert_eq!(x, Rational::parse("802.35"));
let mut x = a.clone(); x -= &b; assert_eq!(x, Rational::parse("-555.45"));
let mut x = a.clone(); x *= &b; assert_eq!(x, Rational::parse("83810.205"));
let mut x = a.clone(); x /= &b; x *= &b; assert_eq!(x, a);
let mut x = b.clone(); x %= &a; assert_eq!(x, Rational::parse("61.65"));
}
impl ops::Neg for &Rational {
type Output = Rational;
fn neg(self) -> Self::Output { Rational(rug::Rational::from(-&self.0)) }
}
impl ops::Add<Self> for &Rational {
type Output = Rational;
fn add(self, rhs: Self) -> Self::Output { Rational(rug::Rational::from(&self.0 + &rhs.0)) }
}
impl ops::Sub<Self> for &Rational {
type Output = Rational;
fn sub(self, rhs: Self) -> Self::Output { Rational(rug::Rational::from(&self.0 - &rhs.0)) }
}
impl ops::Mul<Self> for &Rational {
type Output = Rational;
fn mul(self, rhs: Self) -> Self::Output { Rational(rug::Rational::from(&self.0 * &rhs.0)) }
}
impl ops::Div<Self> for &Rational {
type Output = Rational;
fn div(self, rhs: Self) -> Self::Output {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
return Rational(rug::Rational::from(&self.0 / &rhs.0));
}
}
impl ops::Rem<Self> for &Rational {
type Output = Rational;
fn rem(self, rhs: Self) -> Self::Output {
if rhs.0.cmp0() == Ordering::Equal {
panic!("Divide by zero");
}
let mut quotient = rug::Rational::from(&self.0 / &rhs.0);
quotient.rem_trunc_mut();
quotient *= &rhs.0;
return Rational(quotient);
}
}
#[test]
fn arith_ref_ref() {
let a = Rational::parse("123.45");
let b = Rational::parse("678.90");
assert_eq!(&a + &b, Rational::parse("802.35"));
assert_eq!(&a - &b, Rational::parse("-555.45"));
assert_eq!(&a * &b, Rational::parse("83810.205"));
assert_eq!((&a / &b) * &b, a);
assert_eq!(&b % &a, Rational::parse("61.65"));
}
/*
impl ops::Add<&&Rational> for &Rational {
}
impl ops::Sub<&&Rational> for &Rational {
}
impl ops::Mul<&&Rational> for &Rational {
}
impl ops::Div<&&Rational> for &Rational {
}
impl ops::Rem<&&Rational> for &Rational {
}
*/