malachite_q/comparison/
eq_abs_primitive_float.rs

1// Copyright © 2025 Mikhail Hogrefe
2//
3// This file is part of Malachite.
4//
5// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
6// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
7// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
8
9use crate::Rational;
10use malachite_base::num::arithmetic::traits::{FloorLogBase2, IsPowerOf2};
11use malachite_base::num::comparison::traits::EqAbs;
12use malachite_base::num::conversion::traits::ExactFrom;
13
14macro_rules! impl_eq_abs {
15    ($t: ident) => {
16        impl EqAbs<$t> for Rational {
17            /// Determines whether the absolute values of a [`Rational`] and a primitive float are
18            /// equal.
19            ///
20            /// # Worst-case complexity
21            /// $T(n) = O(n)$
22            ///
23            /// $M(m) = O(m)$
24            ///
25            /// where $T$ is time, $M$ is additional memory, $n$ is `max(self.significant_bits(),
26            /// other.sci_exponent().abs())`, and $m$ is `other.sci_exponent().abs()`.
27            ///
28            /// See [here](super::eq_abs_primitive_float#eq_abs).
29            #[inline]
30            fn eq_abs(&self, other: &$t) -> bool {
31                if !other.is_finite() {
32                    false
33                } else if *other == 0.0 {
34                    *self == 0u32
35                } else {
36                    *self != 0u32
37                        && self.denominator.is_power_of_2()
38                        && self.floor_log_base_2_abs() == other.abs().floor_log_base_2()
39                        && self.eq_abs(&Rational::exact_from(other.abs()))
40                }
41            }
42        }
43
44        impl EqAbs<Rational> for $t {
45            /// Determines whether the absolute values of a primitive float and a [`Rational`] are
46            /// equal.
47            ///
48            /// # Worst-case complexity
49            /// $T(n) = O(n)$
50            ///
51            /// $M(m) = O(m)$
52            ///
53            /// where $T$ is time, $M$ is additional memory, $n$ is `max(self.sci_exponent().abs(),
54            /// other.significant_bits())`, and $m$ is `self.sci_exponent().abs()`.
55            ///
56            /// See [here](super::eq_abs_primitive_float#eq_abs).
57            #[inline]
58            fn eq_abs(&self, other: &Rational) -> bool {
59                other.eq_abs(self)
60            }
61        }
62    };
63}
64apply_to_primitive_floats!(impl_eq_abs);
malachite_q/comparison/eq_abs_primitive_float.rs

malachite_q/comparison/
eq_abs_primitive_float.rs
