var $ = require('../internals/export'); var anObject = require('../internals/an-object'); var numberIsFinite = require('../internals/number-is-finite'); var createIteratorConstructor = require('../internals/create-iterator-constructor'); var InternalStateModule = require('../internals/internal-state'); var SEEDED_RANDOM = 'Seeded Random'; var SEEDED_RANDOM_GENERATOR = SEEDED_RANDOM + ' Generator'; var SEED_TYPE_ERROR = 'Math.seededPRNG() argument should have a "seed" field with a finite value.'; var setInternalState = InternalStateModule.set; var getInternalState = InternalStateModule.getterFor(SEEDED_RANDOM_GENERATOR); var $TypeError = TypeError; var $SeededRandomGenerator = createIteratorConstructor(function SeededRandomGenerator(seed) { setInternalState(this, { type: SEEDED_RANDOM_GENERATOR, seed: seed % 2147483647 }); }, SEEDED_RANDOM, function next() { var state = getInternalState(this); var seed = state.seed = (state.seed * 1103515245 + 12345) % 2147483647; return { value: (seed & 1073741823) / 1073741823, done: false }; }); // `Math.seededPRNG` method // https://github.com/tc39/proposal-seeded-random // based on https://github.com/tc39/proposal-seeded-random/blob/78b8258835b57fc2100d076151ab506bc3202ae6/demo.html $({ target: 'Math', stat: true, forced: true }, { seededPRNG: function seededPRNG(it) { var seed = anObject(it).seed; if (!numberIsFinite(seed)) throw $TypeError(SEED_TYPE_ERROR); return new $SeededRandomGenerator(seed); } });