malachite_q/conversion/
from_integer.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::UnsignedAbs;
11use malachite_base::num::basic::traits::One;
12use malachite_nz::integer::Integer;
13use malachite_nz::natural::Natural;
14
15impl From<Integer> for Rational {
16    /// Converts an [`Integer`] to a [`Rational`], taking the [`Integer`] by value.
17    ///
18    /// # Worst-case complexity
19    /// Constant time and additional memory.
20    ///
21    /// # Examples
22    /// ```
23    /// use malachite_nz::integer::Integer;
24    /// use malachite_q::Rational;
25    ///
26    /// assert_eq!(Rational::from(Integer::from(123)), 123);
27    /// assert_eq!(Rational::from(Integer::from(-123)), -123);
28    /// ```
29    fn from(value: Integer) -> Rational {
30        Rational {
31            sign: value >= 0,
32            numerator: value.unsigned_abs(),
33            denominator: Natural::ONE,
34        }
35    }
36}
37
38impl From<&Integer> for Rational {
39    /// Converts an [`Integer`] to a [`Rational`], taking the [`Integer`] by reference.
40    ///
41    /// # Worst-case complexity
42    /// $T(n) = O(n)$
43    ///
44    /// $M(n) = O(n)$
45    ///
46    /// where $T$ is time, $M$ is additional memory, and $n$ is `value.significant_bits()`.
47    ///
48    /// # Examples
49    /// ```
50    /// use malachite_nz::integer::Integer;
51    /// use malachite_q::Rational;
52    ///
53    /// assert_eq!(Rational::from(&Integer::from(123)), 123);
54    /// assert_eq!(Rational::from(&Integer::from(-123)), -123);
55    /// ```
56    fn from(value: &Integer) -> Rational {
57        Rational {
58            sign: *value >= 0,
59            numerator: value.unsigned_abs(),
60            denominator: Natural::ONE,
61        }
62    }
63}
malachite_q/conversion/from_integer.rs

malachite_q/conversion/
from_integer.rs
