Standard Library: Random

The std::core::random module provides high-quality random number generation using a ChaCha8 PRNG. All functions use thread-local state for performance and safety.

Importing

from std::core::random use { random, random_int, random_seed, random_normal, random_array }

Functions

random

Generate a random floating-point number in [0, 1).

let r = random()   // e.g. 0.734521...

random_int

Generate a random integer in [lo, hi] (inclusive on both ends).

let dice = random_int(1, 6)    // 1, 2, 3, 4, 5, or 6
let coin = random_int(0, 1)    // 0 or 1

random_seed

Seed the RNG for reproducible sequences. Calling random_seed with the same value resets the generator to the same state, so subsequent calls to random produce identical results.

random_seed(42)
let r1 = random()

random_seed(42)
let r2 = random()
// r1 == r2

random_normal

Generate a random number from a normal (Gaussian) distribution with the given mean and standard deviation. The standard deviation must be non-negative.

let shock = random_normal(0.0, 0.02)   // mean=0, std=2%
let height = random_normal(170.0, 10.0) // mean=170cm, std=10cm

random_array

Generate an array of n random numbers in [0, 1).

let samples = random_array(1000)
print(samples.length)   // 1000

Function Reference

Function	Signature	Description
random()	() -> number	Random float in [0, 1)
random_int(lo, hi)	(int, int) -> int	Random integer in [lo, hi]
random_seed(seed)	(int) -> ()	Seed the PRNG for reproducibility
random_normal(mean, std)	(number, number) -> number	Random number from N(mean, std)
random_array(n)	(int) -> Vec<number>	Array of n random floats

See Also

• Standard Library: Math — statistical functions (mean, std, variance)