Struct Rng 

pub struct Rng { /* private fields */ }

A thin wrapper around PCG64 for deterministic generation.

Python passes a master seed; this RNG can produce sub-seeds for parallel batches via fork().

Implementations

impl Rng

pub fn new(seed: u64) -> Self

Create a new RNG from a 64-bit seed.

pub fn next_u64(&mut self) -> u64

Return a random u64.

pub fn next_usize(&mut self, bound: usize) -> usize

Return a random usize in 0..bound.

Uses Lemire’s multiply-shift method instead of % bound, which would otherwise skew low values for any bound that doesn’t divide 2^64.

pub fn next_f64(&mut self) -> f64

Return a random f64 in [0, 1).

pub fn fork(&mut self) -> Self

Fork: create a fresh RNG seeded with a value from this one. Useful for spawning per-batch or per-column RNGs.

Trait Implementations

impl Clone for Rng

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Rng

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

Formats the value using the given formatter.