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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 crate::rational_vector::RationalVector;
use core::ops::{Shr, ShrAssign};
// Shifts every element right by `bits`.
fn shr_ref<T: Copy>(v: &RationalVector, bits: T) -> RationalVector
where
for<'a> &'a Rational: Shr<T, Output = Rational>,
{
RationalVector {
elements: v.elements.iter().map(|x| x >> bits).collect(),
}
}
// Shifts every element right by `bits`, in place.
fn shr_assign<T: Copy>(v: &mut RationalVector, bits: T)
where
Rational: ShrAssign<T>,
{
for x in &mut v.elements {
*x >>= bits;
}
}
macro_rules! impl_rational_vector_shr_unsigned {
($t:ident) => {
impl Shr<$t> for RationalVector {
type Output = RationalVector;
/// Right-shifts a [`RationalVector`] (divides it by a power of 2), taking it by value.
/// Every element is shifted, and the dimension is unchanged.
///
/// $f(v, k) = v/2^k$.
///
/// # Worst-case complexity
/// $T(n, m, k) = O(n + km)$
///
/// $M(n, m, k) = O(n + km)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, $m$ is `bits`, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr).
#[inline]
fn shr(mut self, bits: $t) -> RationalVector {
self >>= bits;
self
}
}
impl Shr<$t> for &RationalVector {
type Output = RationalVector;
/// Right-shifts a [`RationalVector`] (divides it by a power of 2), taking it by
/// reference. Every element is shifted, and the dimension is unchanged.
///
/// $f(v, k) = v/2^k$.
///
/// # Worst-case complexity
/// $T(n, m, k) = O(n + km)$
///
/// $M(n, m, k) = O(n + km)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, $m$ is `bits`, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr).
#[inline]
fn shr(self, bits: $t) -> RationalVector {
shr_ref(self, bits)
}
}
impl ShrAssign<$t> for RationalVector {
/// Right-shifts a [`RationalVector`] (divides it by a power of 2), in place. Every
/// element is shifted, and the dimension is unchanged.
///
/// $v \gets v/2^k$.
///
/// # Worst-case complexity
/// $T(n, m, k) = O(n + km)$
///
/// $M(n, m, k) = O(n + km)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, $m$ is `bits`, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr_assign).
#[inline]
fn shr_assign(&mut self, bits: $t) {
shr_assign(self, bits);
}
}
};
}
apply_to_unsigneds!(impl_rational_vector_shr_unsigned);
macro_rules! impl_rational_vector_shr_signed {
($t:ident) => {
impl Shr<$t> for RationalVector {
type Output = RationalVector;
/// Right-shifts a [`RationalVector`] (divides it by a power of 2), taking it by value.
/// Every element is shifted, and the dimension is unchanged.
///
/// $f(v, k) = v/2^k$.
///
/// A negative `bits` shifts left, multiplying every element by $2^{-k}$.
///
/// # Worst-case complexity
/// $T(n, m, k) = O(n + km)$
///
/// $M(n, m, k) = O(n + km)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, $m$ is `bits.unsigned_abs()`, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr).
#[inline]
fn shr(mut self, bits: $t) -> RationalVector {
self >>= bits;
self
}
}
impl Shr<$t> for &RationalVector {
type Output = RationalVector;
/// Right-shifts a [`RationalVector`] (divides it by a power of 2), taking it by
/// reference. Every element is shifted, and the dimension is unchanged.
///
/// $f(v, k) = v/2^k$.
///
/// A negative `bits` shifts left, multiplying every element by $2^{-k}$.
///
/// # Worst-case complexity
/// $T(n, m, k) = O(n + km)$
///
/// $M(n, m, k) = O(n + km)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, $m$ is `bits.unsigned_abs()`, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr).
#[inline]
fn shr(self, bits: $t) -> RationalVector {
shr_ref(self, bits)
}
}
impl ShrAssign<$t> for RationalVector {
/// Right-shifts a [`RationalVector`] (divides it by a power of 2), in place. Every
/// element is shifted, and the dimension is unchanged.
///
/// $v \gets v/2^k$.
///
/// A negative `bits` shifts left, multiplying every element by $2^{-k}$.
///
/// # Worst-case complexity
/// $T(n, m, k) = O(n + km)$
///
/// $M(n, m, k) = O(n + km)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, $m$ is `bits.unsigned_abs()`, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr_assign).
#[inline]
fn shr_assign(&mut self, bits: $t) {
shr_assign(self, bits);
}
}
};
}
apply_to_signeds!(impl_rational_vector_shr_signed);