mathjs/lib/function/probability/util/seededRNG.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser with support for symbolic computation, comes with a large set of built-in functions and constants, and offers an integrated solution to work with dif

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.createRng = createRng;

var _seedRandom = _interopRequireDefault(require("seed-random"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

// create a random seed here to prevent an infinite loop from seed-random
// inside the factory. Reason is that math.random is defined as a getter/setter
// and seed-random generates a seed from the local entropy by reading every
// defined object including `math` itself. That means that whilst getting
// math.random, it tries to get math.random, etc... an infinite loop.
// See https://github.com/ForbesLindesay/seed-random/issues/6
var singletonRandom =
/* #__PURE__ */
(0, _seedRandom["default"])();

function createRng(randomSeed) {
  var random; // create a new random generator with given seed

  function setSeed(seed) {
    random = seed === null ? singletonRandom : (0, _seedRandom["default"])(String(seed));
  } // initialize a seeded pseudo random number generator with config's random seed


  setSeed(randomSeed); // wrapper function so the rng can be updated via generator

  function rng() {
    return random();
  }

  return rng;
}