Std\Random

Random – pseudo-random number generation.

Provides random integers, floats, element selection, and sequence shuffling. Uses a fast PRNG seeded at program startup. For cryptographically secure randomness, use Std.Crypto.

Functions

int : Int -> Int -> Int

Generate a random integer in the range [lo, hi] (inclusive).

import int from Std\Random in
int 1 100   # => 42 (random)

float : Float

Generate a random float in the range [0.0, 1.0).

import float from Std\Random in
float   # => 0.7312... (random)

choice : [a] -> Int

Pick a random element from a sequence. Returns the element.

import choice from Std\Random in
choice [10, 20, 30]   # => 20 (random)

shuffle : [a] -> [b]

Return a new sequence with elements in random order.

import shuffle from Std\Random in
shuffle [1, 2, 3, 4, 5]   # => [3, 1, 5, 2, 4] (random)