`logos.std.random`

Module std · package logos-std

Types

structRng

struct Rng

Fast seedable pseudo-random number generator based on splitmix64. Deterministic for a given seed; not cryptographically secure — use os_random for that.

Fields

state: u64

Methods

fn next_bool(self: &mut Rng) -> bool

Returns a pseudo-random bool, each value with probability 1/2.

fn next_f64(self: &mut Rng) -> f64

Returns a pseudo-random f64 uniform in [0.0, 1.0) with 53 bits of precision.

fn next_range_i64(self: &mut Rng, lo: i64, hi: i64) -> i64

Returns a pseudo-random i64 uniform in [lo, hi). Caller must ensure hi > lo (hi == lo divides by zero); modulo reduction gives negligible bias unless the span approaches 2^64.

fn next_u32(self: &mut Rng) -> u32

Returns the next pseudo-random u32 (low 32 bits of next_u64).

fn next_u64(self: &mut Rng) -> u64

Returns the next pseudo-random u64 (one raw splitmix64 step).

Functions

fnos_random

fn os_random(buf: *mut u8, len: i64) -> i64

Fills buf with len cryptographic-quality random bytes from the OS. Returns the number of bytes written (len on success) or -1 on error.

fnos_u64

fn os_u64() -> u64

Returns a random u64 from OS entropy. The getrandom result is unchecked; if it fails, the zero-initialized buffer yields 0.

fnrng_from_os

fn rng_from_os() -> Rng

Creates an Rng seeded from OS entropy.

fnrng_new

fn rng_new(seed: u64) -> Rng

Creates an Rng with the given seed; equal seeds yield identical sequences.