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// Copyright © 2026 Mikhail Hogrefe
//
// This file is part of Malachite.
//
// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
use crate::Rational;
use core::ops::Neg;
use malachite_base::num::arithmetic::traits::NegAssign;
use malachite_base::num::basic::traits::Zero;
use malachite_base::num::logic::traits::NotAssign;
impl Neg for Rational {
type Output = Self;
/// Negates a [`Rational`], taking it by value.
///
/// $$
/// f(x) = -x.
/// $$
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_base::num::basic::traits::Zero;
/// use malachite_q::Rational;
///
/// assert_eq!(-Rational::ZERO, 0);
/// assert_eq!((-Rational::from_signeds(22, 7)).to_string(), "-22/7");
/// assert_eq!((-Rational::from_signeds(-22, 7)).to_string(), "22/7");
/// ```
fn neg(mut self) -> Self {
if self.numerator != 0 {
self.sign.not_assign();
}
self
}
}
impl Neg for &Rational {
type Output = Rational;
/// Negates a [`Rational`], taking it by reference.
///
/// $$
/// f(x) = -x.
/// $$
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.significant_bits()`.
///
/// # Examples
/// ```
/// use malachite_base::num::basic::traits::Zero;
/// use malachite_q::Rational;
///
/// assert_eq!(-&Rational::ZERO, 0);
/// assert_eq!((-&Rational::from_signeds(22, 7)).to_string(), "-22/7");
/// assert_eq!((-&Rational::from_signeds(-22, 7)).to_string(), "22/7");
/// ```
fn neg(self) -> Rational {
if self.numerator == 0 {
Rational::ZERO
} else {
Rational {
sign: !self.sign,
numerator: self.numerator.clone(),
denominator: self.denominator.clone(),
}
}
}
}
impl NegAssign for Rational {
/// Negates a [`Rational`] in place.
///
/// $$
/// x \gets -x.
/// $$
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_base::num::arithmetic::traits::NegAssign;
/// use malachite_base::num::basic::traits::Zero;
/// use malachite_q::Rational;
///
/// let mut x = Rational::ZERO;
/// x.neg_assign();
/// assert_eq!(x, 0);
///
/// let mut x = Rational::from_signeds(22, 7);
/// x.neg_assign();
/// assert_eq!(x.to_string(), "-22/7");
///
/// let mut x = Rational::from_signeds(-22, 7);
/// x.neg_assign();
/// assert_eq!(x.to_string(), "22/7");
/// ```
fn neg_assign(&mut self) {
if self.numerator != 0 {
self.sign.not_assign();
}
}
}