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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::Float;
use crate::InnerFloat::{Finite, Infinity, NaN, Zero};
use crate::float_nan;
use core::ops::Neg;
use malachite_base::num::arithmetic::traits::NegAssign;
use malachite_base::num::logic::traits::NotAssign;
impl Neg for Float {
type Output = Self;
/// Negates a [`Float`], taking it by value.
///
/// $$
/// f(x) = -x.
/// $$
///
/// Special cases:
/// - $f(\text{NaN}) = \text{NaN}$
/// - $f(\infty) = -\infty$
/// - $f(-\infty) = \infty$
/// - $f(0.0) = -0.0$
/// - $f(-0.0) = 0.0$
///
/// This function does not overflow or underflow.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_base::num::basic::traits::{
/// Infinity, NaN, NegativeInfinity, NegativeOne, NegativeZero, One, Zero,
/// };
/// use malachite_float::{ComparableFloat, Float};
///
/// assert_eq!(ComparableFloat(-Float::NAN), ComparableFloat(Float::NAN));
/// assert_eq!(-Float::INFINITY, Float::NEGATIVE_INFINITY);
/// assert_eq!(-Float::NEGATIVE_INFINITY, Float::INFINITY);
/// assert_eq!(
/// ComparableFloat(-Float::ZERO),
/// ComparableFloat(Float::NEGATIVE_ZERO)
/// );
/// assert_eq!(
/// ComparableFloat(-Float::NEGATIVE_ZERO),
/// ComparableFloat(Float::ZERO)
/// );
/// assert_eq!(-Float::ONE, Float::NEGATIVE_ONE);
/// assert_eq!(-Float::NEGATIVE_ONE, Float::ONE);
/// ```
#[inline]
fn neg(mut self) -> Self {
self.neg_assign();
self
}
}
impl Neg for &Float {
type Output = Float;
/// Negates a [`Float`], taking it by reference.
///
/// $$
/// f(x) = -x.
/// $$
///
/// Special cases:
/// - $f(\text{NaN}) = \text{NaN}$
/// - $f(\infty) = -\infty$
/// - $f(-\infty) = \infty$
/// - $f(0.0) = -0.0$
/// - $f(-0.0) = 0.0$
///
/// This function does not overflow or underflow.
///
/// # 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::{
/// Infinity, NaN, NegativeInfinity, NegativeOne, NegativeZero, One, Zero,
/// };
/// use malachite_float::{ComparableFloat, Float};
///
/// assert_eq!(ComparableFloat(-&Float::NAN), ComparableFloat(Float::NAN));
/// assert_eq!(-&Float::INFINITY, Float::NEGATIVE_INFINITY);
/// assert_eq!(-&Float::NEGATIVE_INFINITY, Float::INFINITY);
/// assert_eq!(
/// ComparableFloat(-&Float::ZERO),
/// ComparableFloat(Float::NEGATIVE_ZERO)
/// );
/// assert_eq!(
/// ComparableFloat(-&Float::NEGATIVE_ZERO),
/// ComparableFloat(Float::ZERO)
/// );
/// assert_eq!(-&Float::ONE, Float::NEGATIVE_ONE);
/// assert_eq!(-&Float::NEGATIVE_ONE, Float::ONE);
/// ```
fn neg(self) -> Float {
match self {
float_nan!() => float_nan!(),
Float(Infinity { sign }) => Float(Infinity { sign: !*sign }),
Float(Zero { sign }) => Float(Zero { sign: !*sign }),
Float(Finite {
sign,
exponent,
precision,
significand,
}) => Float(Finite {
sign: !*sign,
exponent: *exponent,
precision: *precision,
significand: significand.clone(),
}),
}
}
}
impl NegAssign for Float {
/// Negates a [`Float`] in place.
///
/// $$
/// x \gets -x.
/// $$
///
/// Special cases:
/// - $\text{NaN} \gets \text{NaN}$
/// - $\infty \gets -\infty$
/// - $-\infty \gets \infty$
/// - $0.0 \gets -0.0$
/// - $-0.0 \gets 0.0$
///
/// This function does not overflow or underflow.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_base::num::arithmetic::traits::NegAssign;
/// use malachite_base::num::basic::traits::{
/// Infinity, NaN, NegativeInfinity, NegativeOne, NegativeZero, One, Zero,
/// };
/// use malachite_float::{ComparableFloat, Float};
///
/// let mut x = Float::NAN;
/// x.neg_assign();
/// assert_eq!(ComparableFloat(x), ComparableFloat(Float::NAN));
///
/// let mut x = Float::INFINITY;
/// x.neg_assign();
/// assert_eq!(x, Float::NEGATIVE_INFINITY);
///
/// let mut x = Float::NEGATIVE_INFINITY;
/// x.neg_assign();
/// assert_eq!(x, Float::INFINITY);
///
/// let mut x = Float::ZERO;
/// x.neg_assign();
/// assert_eq!(ComparableFloat(x), ComparableFloat(Float::NEGATIVE_ZERO));
///
/// let mut x = Float::NEGATIVE_ZERO;
/// x.neg_assign();
/// assert_eq!(ComparableFloat(x), ComparableFloat(Float::ZERO));
///
/// let mut x = Float::ONE;
/// x.neg_assign();
/// assert_eq!(x, Float::NEGATIVE_ONE);
///
/// let mut x = Float::NEGATIVE_ONE;
/// x.neg_assign();
/// assert_eq!(x, Float::ONE);
/// ```
fn neg_assign(&mut self) {
if let Self(Infinity { sign } | Zero { sign } | Finite { sign, .. }) = self {
sign.not_assign();
}
}
}