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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::natural::Natural;
use crate::natural_vector::NaturalVector;
use core::ops::{Shr, ShrAssign};
// Shifts every element right by `bits`, taking the floor.
fn shr_ref<T: Copy>(v: &NaturalVector, bits: T) -> NaturalVector
where
for<'a> &'a Natural: Shr<T, Output = Natural>,
{
NaturalVector {
elements: v.elements.iter().map(|x| x >> bits).collect(),
}
}
// Shifts every element right by `bits`, taking the floor, in place.
fn shr_assign<T: Copy>(v: &mut NaturalVector, bits: T)
where
Natural: ShrAssign<T>,
{
for x in &mut v.elements {
*x >>= bits;
}
}
macro_rules! impl_natural_vector_shr_unsigned {
($t:ident) => {
impl Shr<$t> for NaturalVector {
type Output = NaturalVector;
/// Right-shifts a [`NaturalVector`] (divides it by a power of 2 and takes the floor),
/// taking it by value. Every element is shifted, and the dimension is unchanged.
///
/// $f(v, k) = \lfloor v/2^k \rfloor$. The floor is taken entrywise, rounding toward
/// negative infinity; to round differently, use
/// [`entrywise_shr_round`](malachite_base::num::arithmetic::traits::EntrywiseShrRound).
///
/// # Worst-case complexity
/// $T(n, k) = O(n + k)$
///
/// $M(n, k) = O(n + k)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr). /// This is equivalent to
/// `_fmpz_vec_scalar_fdiv_q_2exp` from `fmpz_vec/scalar.c`, FLINT 3.6.0.
#[inline]
fn shr(mut self, bits: $t) -> NaturalVector {
self >>= bits;
self
}
}
impl Shr<$t> for &NaturalVector {
type Output = NaturalVector;
/// Right-shifts a [`NaturalVector`] (divides it by a power of 2 and takes the floor),
/// taking it by reference. Every element is shifted, and the dimension is unchanged.
///
/// $f(v, k) = \lfloor v/2^k \rfloor$. The floor is taken entrywise, rounding toward
/// negative infinity; to round differently, use
/// [`entrywise_shr_round`](malachite_base::num::arithmetic::traits::EntrywiseShrRound).
///
/// # Worst-case complexity
/// $T(n, k) = O(n + k)$
///
/// $M(n, k) = O(n + k)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr). /// This is equivalent to
/// `_fmpz_vec_scalar_fdiv_q_2exp` from `fmpz_vec/scalar.c`, FLINT 3.6.0.
#[inline]
fn shr(self, bits: $t) -> NaturalVector {
shr_ref(self, bits)
}
}
impl ShrAssign<$t> for NaturalVector {
/// Right-shifts a [`NaturalVector`] (divides it by a power of 2 and takes the floor),
/// in place. Every element is shifted, and the dimension is unchanged.
///
/// $v \gets \lfloor v/2^k \rfloor$. The floor is taken entrywise, rounding toward
/// negative infinity; to round differently, use
/// [`entrywise_shr_round`](malachite_base::num::arithmetic::traits::EntrywiseShrRound).
///
/// # Worst-case complexity
/// $T(n, k) = O(n + k)$
///
/// $M(k) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, $n$ is the total number of bits of the
/// elements, and $k$ is `self.dimension()`.
///
/// # Examples
/// See [here](super::shr#shr_assign). /// This is equivalent to
/// `_fmpz_vec_scalar_fdiv_q_2exp` from `fmpz_vec/scalar.c`, FLINT 3.6.0.
#[inline]
fn shr_assign(&mut self, bits: $t) {
shr_assign(self, bits);
}
}
};
}
apply_to_unsigneds!(impl_natural_vector_shr_unsigned);
macro_rules! impl_natural_vector_shr_signed {
($t:ident) => {
impl Shr<$t> for NaturalVector {
type Output = NaturalVector;
/// Right-shifts a [`NaturalVector`] (divides or multiplies it by a power of 2), taking
/// it by value. Every element is shifted, and the dimension is unchanged.
///
/// $f(v, k) = \lfloor v/2^k \rfloor$. The floor is taken entrywise, rounding toward
/// negative infinity; to round differently, use
/// [`entrywise_shr_round`](malachite_base::num::arithmetic::traits::EntrywiseShrRound).
///
/// 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: $t) -> NaturalVector {
self >>= bits;
self
}
}
impl Shr<$t> for &NaturalVector {
type Output = NaturalVector;
/// Right-shifts a [`NaturalVector`] (divides or multiplies it by a power of 2), taking
/// it by reference. Every element is shifted, and the dimension is unchanged.
///
/// $f(v, k) = \lfloor v/2^k \rfloor$. The floor is taken entrywise, rounding toward
/// negative infinity; to round differently, use
/// [`entrywise_shr_round`](malachite_base::num::arithmetic::traits::EntrywiseShrRound).
///
/// 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: $t) -> NaturalVector {
shr_ref(self, bits)
}
}
impl ShrAssign<$t> for NaturalVector {
/// Right-shifts a [`NaturalVector`] (divides or multiplies it by a power of 2), in
/// place. Every element is shifted, and the dimension is unchanged.
///
/// $v \gets \lfloor v/2^k \rfloor$. The floor is taken entrywise, rounding toward
/// negative infinity; to round differently, use
/// [`entrywise_shr_round`](malachite_base::num::arithmetic::traits::EntrywiseShrRound).
///
/// 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_natural_vector_shr_signed);