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#![crate_name = "rand"]
#![crate_type = "rlib"]
#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk.png",
html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
html_root_url = "https://doc.rust-lang.org/nightly/",
html_playground_url = "https://play.rust-lang.org/",
test(attr(deny(warnings))))]
#![deny(warnings)]
#![deny(missing_debug_implementations)]
#![no_std]
#![unstable(feature = "rand",
reason = "use `rand` from crates.io",
issue = "27703")]
#![feature(core_intrinsics)]
#![feature(staged_api)]
#![feature(step_by)]
#![feature(custom_attribute)]
#![feature(specialization)]
#![allow(unused_attributes)]
#![cfg_attr(not(test), feature(core_float))]
#![cfg_attr(test, feature(test, rand))]
#![allow(deprecated)]
#[cfg(test)]
#[macro_use]
extern crate std;
use core::fmt;
use core::f64;
use core::intrinsics;
use core::marker::PhantomData;
pub use isaac::{Isaac64Rng, IsaacRng};
pub use chacha::ChaChaRng;
use distributions::{IndependentSample, Range};
use distributions::range::SampleRange;
#[cfg(test)]
const RAND_BENCH_N: u64 = 100;
pub mod distributions;
pub mod isaac;
pub mod chacha;
pub mod reseeding;
mod rand_impls;
#[doc(hidden)]
trait FloatMath: Sized {
fn exp(self) -> Self;
fn ln(self) -> Self;
fn sqrt(self) -> Self;
fn powf(self, n: Self) -> Self;
}
impl FloatMath for f64 {
#[inline]
fn exp(self) -> f64 {
unsafe { intrinsics::expf64(self) }
}
#[inline]
fn ln(self) -> f64 {
unsafe { intrinsics::logf64(self) }
}
#[inline]
fn powf(self, n: f64) -> f64 {
unsafe { intrinsics::powf64(self, n) }
}
#[inline]
fn sqrt(self) -> f64 {
if self < 0.0 {
f64::NAN
} else {
unsafe { intrinsics::sqrtf64(self) }
}
}
}
#[doc(hidden)]
pub trait Rand: Sized {
fn rand<R: Rng>(rng: &mut R) -> Self;
}
pub trait Rng: Sized {
fn next_u32(&mut self) -> u32;
fn next_u64(&mut self) -> u64 {
((self.next_u32() as u64) << 32) | (self.next_u32() as u64)
}
fn next_f32(&mut self) -> f32 {
const MANTISSA_BITS: usize = 24;
const IGNORED_BITS: usize = 8;
const SCALE: f32 = (1u64 << MANTISSA_BITS) as f32;
(self.next_u32() >> IGNORED_BITS) as f32 / SCALE
}
fn next_f64(&mut self) -> f64 {
const MANTISSA_BITS: usize = 53;
const IGNORED_BITS: usize = 11;
const SCALE: f64 = (1u64 << MANTISSA_BITS) as f64;
(self.next_u64() >> IGNORED_BITS) as f64 / SCALE
}
fn fill_bytes(&mut self, dest: &mut [u8]) {
let mut count = 0;
let mut num = 0;
for byte in dest {
if count == 0 {
num = self.next_u64();
count = 8;
}
*byte = (num & 0xff) as u8;
num >>= 8;
count -= 1;
}
}
#[inline(always)]
fn gen<T: Rand>(&mut self) -> T {
Rand::rand(self)
}
fn gen_iter<'a, T: Rand>(&'a mut self) -> Generator<'a, T, Self> {
Generator {
rng: self,
_marker: PhantomData,
}
}
fn gen_range<T: PartialOrd + SampleRange>(&mut self, low: T, high: T) -> T {
assert!(low < high, "Rng.gen_range called with low >= high");
Range::new(low, high).ind_sample(self)
}
fn gen_weighted_bool(&mut self, n: usize) -> bool {
n <= 1 || self.gen_range(0, n) == 0
}
fn gen_ascii_chars<'a>(&'a mut self) -> AsciiGenerator<'a, Self> {
AsciiGenerator { rng: self }
}
fn choose<'a, T>(&mut self, values: &'a [T]) -> Option<&'a T> {
if values.is_empty() {
None
} else {
Some(&values[self.gen_range(0, values.len())])
}
}
fn shuffle<T>(&mut self, values: &mut [T]) {
let mut i = values.len();
while i >= 2 {
i -= 1;
values.swap(i, self.gen_range(0, i + 1));
}
}
}
pub struct Generator<'a, T, R: 'a> {
rng: &'a mut R,
_marker: PhantomData<T>,
}
impl<'a, T: Rand, R: Rng> Iterator for Generator<'a, T, R> {
type Item = T;
fn next(&mut self) -> Option<T> {
Some(self.rng.gen())
}
}
impl<'a, T, R: fmt::Debug> fmt::Debug for Generator<'a, T, R> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Generator")
.field("rng", &self.rng)
.finish()
}
}
pub struct AsciiGenerator<'a, R: 'a> {
rng: &'a mut R,
}
impl<'a, R: Rng> Iterator for AsciiGenerator<'a, R> {
type Item = char;
fn next(&mut self) -> Option<char> {
const GEN_ASCII_STR_CHARSET: &'static [u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZ\
abcdefghijklmnopqrstuvwxyz\
0123456789";
Some(*self.rng.choose(GEN_ASCII_STR_CHARSET).unwrap() as char)
}
}
impl<'a, R: fmt::Debug> fmt::Debug for AsciiGenerator<'a, R> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("AsciiGenerator")
.field("rng", &self.rng)
.finish()
}
}
pub trait SeedableRng<Seed>: Rng {
fn reseed(&mut self, Seed);
fn from_seed(seed: Seed) -> Self;
}
#[derive(Clone, Debug)]
pub struct XorShiftRng {
x: u32,
y: u32,
z: u32,
w: u32,
}
impl XorShiftRng {
pub fn new_unseeded() -> XorShiftRng {
XorShiftRng {
x: 0x193a6754,
y: 0xa8a7d469,
z: 0x97830e05,
w: 0x113ba7bb,
}
}
}
impl Rng for XorShiftRng {
#[inline]
fn next_u32(&mut self) -> u32 {
let x = self.x;
let t = x ^ (x << 11);
self.x = self.y;
self.y = self.z;
self.z = self.w;
let w = self.w;
self.w = w ^ (w >> 19) ^ (t ^ (t >> 8));
self.w
}
}
impl SeedableRng<[u32; 4]> for XorShiftRng {
fn reseed(&mut self, seed: [u32; 4]) {
assert!(!seed.iter().all(|&x| x == 0),
"XorShiftRng.reseed called with an all zero seed.");
self.x = seed[0];
self.y = seed[1];
self.z = seed[2];
self.w = seed[3];
}
fn from_seed(seed: [u32; 4]) -> XorShiftRng {
assert!(!seed.iter().all(|&x| x == 0),
"XorShiftRng::from_seed called with an all zero seed.");
XorShiftRng {
x: seed[0],
y: seed[1],
z: seed[2],
w: seed[3],
}
}
}
impl Rand for XorShiftRng {
fn rand<R: Rng>(rng: &mut R) -> XorShiftRng {
let mut tuple: (u32, u32, u32, u32) = rng.gen();
while tuple == (0, 0, 0, 0) {
tuple = rng.gen();
}
let (x, y, z, w) = tuple;
XorShiftRng {
x: x,
y: y,
z: z,
w: w,
}
}
}
pub struct Open01<F>(pub F);
impl<F: fmt::Debug> fmt::Debug for Open01<F> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_tuple("Open01")
.field(&self.0)
.finish()
}
}
pub struct Closed01<F>(pub F);
impl<F: fmt::Debug> fmt::Debug for Closed01<F> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_tuple("Closed01")
.field(&self.0)
.finish()
}
}
#[cfg(test)]
mod test {
use std::__rand as rand;
pub struct MyRng<R> {
inner: R,
}
impl<R: rand::Rng> ::Rng for MyRng<R> {
fn next_u32(&mut self) -> u32 {
rand::Rng::next_u32(&mut self.inner)
}
}
pub fn rng() -> MyRng<rand::ThreadRng> {
MyRng { inner: rand::thread_rng() }
}
pub fn weak_rng() -> MyRng<rand::ThreadRng> {
MyRng { inner: rand::thread_rng() }
}
}