std.random

Pseudorandom number generation.

import std.random

Functions

next

random.next() int

Returns a random integer (full range).

between

random.between(low: int, high: int) int

Returns a random integer in [low, high] (inclusive).

let die = random.between(1, 6)

decimal

random.decimal() float

Returns a random float in [0.0, 1.0).

decimal_between

random.decimal_between(low: float, high: float) float

Returns a random float in [low, high).

let temp = random.decimal_between(36.0, 38.0)

coin

random.coin() bool

Returns true or false with equal probability.

seed

random.seed(s: int)

Seeds the random number generator. Same seed produces the same sequence, useful for reproducible tests.

random.seed(42)
let a = random.next()
random.seed(42)
let b = random.next()
// a == b

Example

import std.random

fn main() {
    // Roll 5 dice
    let mut i = 0
    while i < 5 {
        print(f"Roll: {random.between(1, 6)}")
        i = i + 1
    }

    // Reproducible sequence
    random.seed(99)
    let x = random.between(1, 100)
    let y = random.between(1, 100)
    print(f"Seeded: {x}, {y}")
}