malachite_float/comparison/
partial_eq_natural.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::Float;
10use crate::InnerFloat::{Finite, Zero};
11use core::cmp::Ordering::*;
12use malachite_base::num::logic::traits::SignificantBits;
13use malachite_nz::natural::Natural;
14
15impl PartialEq<Natural> for Float {
16    /// Determines whether a [`Float`] is equal to a [`Natural`].
17    ///
18    /// $\infty$, $-\infty$, and NaN are not equal to any [`Natural`]. Both the [`Float`] zero and
19    /// the [`Float`] negative zero are equal to the [`Natural`] zero.
20    ///
21    /// # Worst-case complexity
22    /// $T(n) = O(n)$
23    ///
24    /// $M(n) = O(1)$
25    ///
26    /// where $T$ is time, $M$ is additional memory, and $n$ is `min(self.significant_bits(),
27    /// other.significant_bits())`.
28    ///
29    /// # Examples
30    /// ```
31    /// use malachite_base::num::basic::traits::{One, OneHalf};
32    /// use malachite_float::Float;
33    /// use malachite_nz::natural::Natural;
34    ///
35    /// assert!(Float::from(123) == Natural::from(123u32));
36    /// assert!(Float::ONE_HALF != Natural::ONE);
37    /// ```
38    fn eq(&self, other: &Natural) -> bool {
39        match self {
40            float_either_zero!() => *other == 0u32,
41            Self(Finite {
42                sign,
43                exponent,
44                significand,
45                ..
46            }) => {
47                *sign
48                    && *other != 0u32
49                    && *exponent >= 0
50                    && other.significant_bits() == u64::from(exponent.unsigned_abs())
51                    && significand.cmp_normalized(other) == Equal
52            }
53            _ => false,
54        }
55    }
56}
57
58impl PartialEq<Float> for Natural {
59    /// Determines whether a [`Natural`] is equal to a [`Float`].
60    ///
61    /// No [`Natural`] is equal to $\infty$, $-\infty$, or NaN. The [`Natural`] zero is equal to
62    /// both the [`Float`] zero and the [`Float`] negative zero.
63    ///
64    /// # Worst-case complexity
65    /// $T(n) = O(n)$
66    ///
67    /// $M(n) = O(1)$
68    ///
69    /// where $T$ is time, $M$ is additional memory, and $n$ is `min(self.significant_bits(),
70    /// other.significant_bits())`.
71    ///
72    /// # Examples
73    /// ```
74    /// use malachite_base::num::basic::traits::{One, OneHalf};
75    /// use malachite_float::Float;
76    /// use malachite_nz::natural::Natural;
77    ///
78    /// assert!(Natural::from(123u32) == Float::from(123));
79    /// assert!(Natural::ONE != Float::ONE_HALF);
80    /// ```
81    #[inline]
82    fn eq(&self, other: &Float) -> bool {
83        other == self
84    }
85}
malachite_float/comparison/partial_eq_natural.rs

malachite_float/comparison/
partial_eq_natural.rs
