Struct StreamRng 

pub struct StreamRng { /* private fields */ }

A reproducible random-number stream: ChaCha20 (original 64-bit counter, 64-bit nonce layout) keyed by seed, with the stream id as the nonce. Each stream has 2^64 blocks, far more than any simulation needs.

The output for a given (seed, stream) is part of the crate’s stability contract; changing it requires a deliberate, documented version bump.

Example

use prospicio_core::StreamRng;

let mut a = StreamRng::new(42, 7);
let mut b = StreamRng::new(42, 7);
assert_eq!(a.next_u64(), b.next_u64());

Implementations

impl StreamRng

pub fn new(seed: u64, stream: u64) -> Self

Stream stream of the generator keyed by seed.

pub fn next_u64(&mut self) -> u64

Next uniformly distributed 64-bit integer.

pub fn next_open01(&mut self) -> f64

Next uniform draw strictly inside (0, 1), on a grid of spacing 2^-53, so it can be passed to any quantile function without producing an infinite value.

Trait Implementations

impl Clone for StreamRng

fn clone(&self) -> StreamRng

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StreamRng

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.