malachite_float/float/conversion/
from_gaussian_integer.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_nz::gaussian_integer::GaussianInteger;
12
13#[derive(Clone, Copy, Debug, Eq, PartialEq)]
14pub struct FloatFromGaussianIntegerError;
15
16impl TryFrom<GaussianInteger> for Float {
17    type Error = FloatFromGaussianIntegerError;
18
19    /// Converts a [`GaussianInteger`] to a [`Float`], taking the [`GaussianInteger`] by value. If
20    /// the [`GaussianInteger`] is not real, an error is returned.
21    ///
22    /// If the [`GaussianInteger`] is nonzero, the precision of the [`Float`] is the minimum
23    /// possible precision to represent it exactly.
24    ///
25    /// # Worst-case complexity
26    /// $T(n) = O(n)$
27    ///
28    /// $M(n) = O(n)$
29    ///
30    /// where $T$ is time, $M$ is additional memory, and $n$ is `x.real.significant_bits()`.
31    ///
32    /// # Examples
33    /// ```
34    /// use malachite_float::Float;
35    /// use malachite_float::float::conversion::from_gaussian_integer::*;
36    /// use malachite_nz::gaussian_integer::GaussianInteger;
37    /// use std::str::FromStr;
38    ///
39    /// let x = GaussianInteger::from_str("123").unwrap();
40    /// assert_eq!(Float::try_from(x).unwrap().to_string(), "123.0");
41    ///
42    /// let x = GaussianInteger::from_str("2-3i").unwrap();
43    /// assert_eq!(Float::try_from(x), Err(FloatFromGaussianIntegerError));
44    /// ```
45    fn try_from(x: GaussianInteger) -> Result<Self, Self::Error> {
46        if x.imaginary == 0u32 {
47            Self::try_from(x.real).map_err(|_| FloatFromGaussianIntegerError)
48        } else {
49            Err(FloatFromGaussianIntegerError)
50        }
51    }
52}
53
54impl TryFrom<&GaussianInteger> for Float {
55    type Error = FloatFromGaussianIntegerError;
56
57    /// Converts a [`GaussianInteger`] to a [`Float`], taking the [`GaussianInteger`] by reference.
58    /// If the [`GaussianInteger`] is not real, an error is returned.
59    ///
60    /// If the [`GaussianInteger`] is nonzero, the precision of the [`Float`] is the minimum
61    /// possible precision to represent it exactly.
62    ///
63    /// # Worst-case complexity
64    /// $T(n) = O(n)$
65    ///
66    /// $M(n) = O(n)$
67    ///
68    /// where $T$ is time, $M$ is additional memory, and $n$ is `x.real.significant_bits()`.
69    ///
70    /// # Examples
71    /// ```
72    /// use malachite_float::Float;
73    /// use malachite_float::float::conversion::from_gaussian_integer::*;
74    /// use malachite_nz::gaussian_integer::GaussianInteger;
75    /// use std::str::FromStr;
76    ///
77    /// let x = GaussianInteger::from_str("123").unwrap();
78    /// assert_eq!(Float::try_from(&x).unwrap().to_string(), "123.0");
79    ///
80    /// let x = GaussianInteger::from_str("2-3i").unwrap();
81    /// assert_eq!(Float::try_from(&x), Err(FloatFromGaussianIntegerError));
82    /// ```
83    fn try_from(x: &GaussianInteger) -> Result<Self, Self::Error> {
84        if x.imaginary == 0u32 {
85            Self::try_from(&x.real).map_err(|_| FloatFromGaussianIntegerError)
86        } else {
87            Err(FloatFromGaussianIntegerError)
88        }
89    }
90}
91
92impl ConvertibleFrom<&GaussianInteger> for Float {
93    /// Determines whether a [`GaussianInteger`] can be converted to a [`Float`] (that is, whether
94    /// it is real), taking the [`GaussianInteger`] by reference.
95    ///
96    /// # Worst-case complexity
97    /// $T(n) = O(n)$
98    ///
99    /// $M(n) = O(1)$
100    ///
101    /// where $T$ is time, $M$ is additional memory, and $n$ is `x.real.significant_bits()`.
102    ///
103    /// # Examples
104    /// ```
105    /// use malachite_base::num::conversion::traits::ConvertibleFrom;
106    /// use malachite_float::Float;
107    /// use malachite_nz::gaussian_integer::GaussianInteger;
108    /// use std::str::FromStr;
109    ///
110    /// let x = GaussianInteger::from_str("123").unwrap();
111    /// assert_eq!(Float::convertible_from(&x), true);
112    ///
113    /// let x = GaussianInteger::from_str("2-3i").unwrap();
114    /// assert_eq!(Float::convertible_from(&x), false);
115    /// ```
116    #[inline]
117    fn convertible_from(x: &GaussianInteger) -> bool {
118        x.imaginary == 0u32 && Self::convertible_from(&x.real)
119    }
120}
malachite_float/float/conversion/from_gaussian_integer.rs

malachite_float/float/conversion/
from_gaussian_integer.rs
