pure-rand

import { uniformIntDistribution } from 'pure-rand/distribution/UniformIntDistribution'; import { xoroshiro128plus } from 'pure-rand/generator/xoroshiro128plus'; import { purify } from 'pure-rand/utils/purify'; const uniformIntDistributionPure = purify(uniformIntDistribution); // A seed for reproducibility const seed = 42; // Initialize the PRNG. This creates an 'impure' generator. const rng1 = xoroshiro128plus(seed); // Use the purified distribution. It returns both the value and the *next* generator state. const [firstDiceValue, rng2] = uniformIntDistributionPure(rng1, 1, 6); console.log(`First roll: ${firstDiceValue}, Next RNG state hash: ${rng2.min()}`); // Example: 2 const [secondDiceValue, rng3] = uniformIntDistributionPure(rng2, 1, 6); console.log(`Second roll: ${secondDiceValue}, Next RNG state hash: ${rng3.min()}`); // Example: 4 const [thirdDiceValue, rng4] = uniformIntDistributionPure(rng3, 1, 6); console.log(`Third roll: ${thirdDiceValue}, Next RNG state hash: ${rng4.min()}`); // Example: 6 // Demonstrating purity: Calling with rng1 again produces the same result const [replayedFirstValue, _] = uniformIntDistributionPure(rng1, 1, 6); console.log(`Replayed first roll (from rng1): ${replayedFirstValue}`); // Example: 2 // Example of directly using an impure generator (less common in pure-rand's philosophy) const impureRng = xoroshiro128plus(100); const val1 = uniformInt(impureRng, 1, 10); const val2 = uniformInt(impureRng, 1, 10); console.log(`Impure sequence: ${val1}, ${val2}`);