malachite_float/float/conversion/
gaussian_rational_from_float.rs

1// Copyright © 2026 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 malachite_base::num::conversion::traits::ConvertibleFrom;
11use malachite_q::Rational;
12use malachite_q::gaussian_rational::GaussianRational;
13
14#[derive(Clone, Copy, Debug, Eq, PartialEq)]
15pub struct GaussianRationalFromFloatError;
16
17impl TryFrom<Float> for GaussianRational {
18    type Error = GaussianRationalFromFloatError;
19
20    /// Converts a [`Float`] to a [`GaussianRational`], producing a purely real value and taking the
21    /// [`Float`] by value. If the [`Float`] is NaN or infinite, an error is returned.
22    ///
23    /// # Worst-case complexity
24    /// $T(n) = O(n)$
25    ///
26    /// $M(n) = O(n)$
27    ///
28    /// where $T$ is time, $M$ is additional memory, and $n$ is `x.significant_bits()`.
29    ///
30    /// # Examples
31    /// ```
32    /// use malachite_base::num::basic::traits::{Infinity, NaN};
33    /// use malachite_float::Float;
34    /// use malachite_float::float::conversion::gaussian_rational_from_float::*;
35    /// use malachite_q::gaussian_rational::GaussianRational;
36    ///
37    /// let x = Float::from(123);
38    /// assert_eq!(GaussianRational::try_from(x).unwrap().to_string(), "123");
39    ///
40    /// let x = Float::from(1.5);
41    /// assert_eq!(GaussianRational::try_from(x).unwrap().to_string(), "3/2");
42    ///
43    /// assert_eq!(
44    ///     GaussianRational::try_from(Float::NAN),
45    ///     Err(GaussianRationalFromFloatError)
46    /// );
47    /// assert_eq!(
48    ///     GaussianRational::try_from(Float::INFINITY),
49    ///     Err(GaussianRationalFromFloatError)
50    /// );
51    /// ```
52    #[inline]
53    fn try_from(x: Float) -> Result<Self, Self::Error> {
54        Rational::try_from(x)
55            .map(Self::from)
56            .map_err(|_| GaussianRationalFromFloatError)
57    }
58}
59
60impl TryFrom<&Float> for GaussianRational {
61    type Error = GaussianRationalFromFloatError;
62
63    /// Converts a [`Float`] to a [`GaussianRational`], producing a purely real value and taking the
64    /// [`Float`] by reference. If the [`Float`] is NaN or infinite, an error is returned.
65    ///
66    /// # Worst-case complexity
67    /// $T(n) = O(n)$
68    ///
69    /// $M(n) = O(n)$
70    ///
71    /// where $T$ is time, $M$ is additional memory, and $n$ is `x.significant_bits()`.
72    ///
73    /// # Examples
74    /// ```
75    /// use malachite_base::num::basic::traits::{Infinity, NaN};
76    /// use malachite_float::Float;
77    /// use malachite_float::float::conversion::gaussian_rational_from_float::*;
78    /// use malachite_q::gaussian_rational::GaussianRational;
79    ///
80    /// let x = Float::from(123);
81    /// assert_eq!(GaussianRational::try_from(&x).unwrap().to_string(), "123");
82    ///
83    /// let x = Float::from(1.5);
84    /// assert_eq!(GaussianRational::try_from(&x).unwrap().to_string(), "3/2");
85    ///
86    /// assert_eq!(
87    ///     GaussianRational::try_from(&Float::NAN),
88    ///     Err(GaussianRationalFromFloatError)
89    /// );
90    /// assert_eq!(
91    ///     GaussianRational::try_from(&Float::INFINITY),
92    ///     Err(GaussianRationalFromFloatError)
93    /// );
94    /// ```
95    #[inline]
96    fn try_from(x: &Float) -> Result<Self, Self::Error> {
97        Rational::try_from(x)
98            .map(Self::from)
99            .map_err(|_| GaussianRationalFromFloatError)
100    }
101}
102
103impl ConvertibleFrom<&Float> for GaussianRational {
104    /// Determines whether a [`Float`] can be converted to a [`GaussianRational`] (that is, whether
105    /// it is finite), taking the [`Float`] by reference.
106    ///
107    /// # Worst-case complexity
108    /// Constant time and additional memory.
109    ///
110    /// # Examples
111    /// ```
112    /// use malachite_base::num::basic::traits::{Infinity, NaN};
113    /// use malachite_base::num::conversion::traits::ConvertibleFrom;
114    /// use malachite_float::Float;
115    /// use malachite_q::gaussian_rational::GaussianRational;
116    ///
117    /// assert_eq!(GaussianRational::convertible_from(&Float::from(123)), true);
118    /// assert_eq!(GaussianRational::convertible_from(&Float::from(1.5)), true);
119    /// assert_eq!(GaussianRational::convertible_from(&Float::NAN), false);
120    /// assert_eq!(GaussianRational::convertible_from(&Float::INFINITY), false);
121    /// ```
122    #[inline]
123    fn convertible_from(x: &Float) -> bool {
124        Rational::convertible_from(x)
125    }
126}
malachite_float/float/conversion/gaussian_rational_from_float.rs

malachite_float/float/conversion/
gaussian_rational_from_float.rs
