dashu-int 0.6.0

Arbitrary-precision integer math library for Rust, balancing ergonomics and efficiency. Provides UBig and IBig (unsigned and signed), with small values inlined on the stack. Efficient arithmetic, modular arithmetic, and number theory (pow, ilog, gcd, gcd_ext); two's-complement bit operations; parsing and formatting in base 2-36; optional serde, rand, num-traits, rkyv, and zeroize.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155

use crate::{
    arch::word::{DoubleWord, Word},
    ibig::IBig,
    ops::UnsignedAbs,
    ubig::UBig,
};
use rand_v08::{
    distributions::uniform::{SampleBorrow, SampleUniform, UniformSampler},
    prelude::Distribution,
    Rng,
};

use super::rand::*;

/// Adapter exposing a rand 0.8 [`Rng`] as a [`BitRng`].
pub struct RngBridge<'a, R: Rng + ?Sized>(pub &'a mut R);

impl<'a, R: Rng + ?Sized> BitRng for RngBridge<'a, R> {
    #[inline]
    fn next_word(&mut self) -> Word {
        self.0.gen()
    }
    #[inline]
    fn next_double_word(&mut self) -> DoubleWord {
        self.0.gen()
    }
    #[inline]
    fn next_bool(&mut self) -> bool {
        self.0.gen()
    }
    #[inline]
    fn fill_words(&mut self, words: &mut [Word]) {
        self.0.fill(words)
    }
    #[inline]
    fn gen_word_inclusive(&mut self, high: Word) -> Word {
        self.0.gen_range(0..=high)
    }
    #[inline]
    fn gen_dword_exclusive(&mut self, high: DoubleWord) -> DoubleWord {
        self.0.gen_range(0..high)
    }
}

fn bridge<R: Rng + ?Sized>(rng: &mut R) -> RngBridge<'_, R> {
    RngBridge(rng)
}

impl Distribution<UBig> for UniformBits {
    #[inline]
    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> UBig {
        self.sample_ubig(&mut bridge(rng))
    }
}

impl Distribution<IBig> for UniformBits {
    #[inline]
    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> IBig {
        self.sample_ibig(&mut bridge(rng))
    }
}

impl Distribution<UBig> for UniformBelow<'_> {
    #[inline]
    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> UBig {
        self.sample_ubig(&mut bridge(rng))
    }
}

impl Distribution<IBig> for UniformBelow<'_> {
    #[inline]
    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> IBig {
        self.sample_ibig(&mut bridge(rng))
    }
}

impl UniformSampler for UniformUBig {
    type X = UBig;

    #[inline]
    fn new<B1, B2>(low: B1, high: B2) -> UniformUBig
    where
        B1: SampleBorrow<UBig> + Sized,
        B2: SampleBorrow<UBig> + Sized,
    {
        if high.borrow() <= low.borrow() {
            panic!("empty range for random generation");
        }
        let range = high.borrow() - low.borrow();
        UniformUBig::from_parts(range, low.borrow().clone())
    }

    #[inline]
    fn new_inclusive<B1, B2>(low: B1, high: B2) -> UniformUBig
    where
        B1: SampleBorrow<UBig> + Sized,
        B2: SampleBorrow<UBig> + Sized,
    {
        if high.borrow() < low.borrow() {
            panic!("empty range for random generation");
        }
        let range = high.borrow() - low.borrow() + UBig::ONE;
        UniformUBig::from_parts(range, low.borrow().clone())
    }

    #[inline]
    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> UBig {
        let mut b = bridge(rng);
        UniformUBig::sample(self, &mut b)
    }
}

impl UniformSampler for UniformIBig {
    type X = IBig;

    #[inline]
    fn new<B1, B2>(low: B1, high: B2) -> UniformIBig
    where
        B1: SampleBorrow<IBig> + Sized,
        B2: SampleBorrow<IBig> + Sized,
    {
        if high.borrow() <= low.borrow() {
            panic!("empty range for random generation");
        }
        let range = high.borrow() - low.borrow();
        UniformIBig::from_parts(range.unsigned_abs(), low.borrow().clone())
    }

    #[inline]
    fn new_inclusive<B1, B2>(low: B1, high: B2) -> UniformIBig
    where
        B1: SampleBorrow<IBig> + Sized,
        B2: SampleBorrow<IBig> + Sized,
    {
        if high.borrow() < low.borrow() {
            panic!("empty range for random generation");
        }
        let range = high.borrow() - low.borrow() + IBig::ONE;
        UniformIBig::from_parts(range.unsigned_abs(), low.borrow().clone())
    }

    #[inline]
    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> IBig {
        let mut b = bridge(rng);
        UniformIBig::sample(self, &mut b)
    }
}

impl SampleUniform for UBig {
    type Sampler = UniformUBig;
}

impl SampleUniform for IBig {
    type Sampler = UniformIBig;
}