42 lines
971 B
JavaScript
42 lines
971 B
JavaScript
|
'use strict';
|
||
|
|
|
||
|
|
Object.defineProperty(exports, '__esModule', {
|
||
|
|
value: true
|
||
|
|
});
|
||
|
|
exports.default = shuffleArray;
|
||
|
|
exports.rngBuilder = void 0;
|
||
|
|
var _pureRand = require('pure-rand');
|
||
|
|
/**
|
||
|
|
* Copyright (c) Meta Platforms, Inc. and affiliates.
|
||
|
|
*
|
||
|
|
* This source code is licensed under the MIT license found in the
|
||
|
|
* LICENSE file in the root directory of this source tree.
|
||
|
|
*/
|
||
|
|
|
||
|
|
// Generates [from, to] inclusive
|
||
|
|
|
||
|
|
const rngBuilder = seed => {
|
||
|
|
const gen = (0, _pureRand.xoroshiro128plus)(seed);
|
||
|
|
return {
|
||
|
|
next: (from, to) =>
|
||
|
|
(0, _pureRand.unsafeUniformIntDistribution)(from, to, gen)
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
// Fisher-Yates shuffle
|
||
|
|
// This is performed in-place
|
||
|
|
exports.rngBuilder = rngBuilder;
|
||
|
|
function shuffleArray(array, random) {
|
||
|
|
const length = array.length;
|
||
|
|
if (length === 0) {
|
||
|
|
return [];
|
||
|
|
}
|
||
|
|
for (let i = 0; i < length; i++) {
|
||
|
|
const n = random.next(i, length - 1);
|
||
|
|
const value = array[i];
|
||
|
|
array[i] = array[n];
|
||
|
|
array[n] = value;
|
||
|
|
}
|
||
|
|
return array;
|
||
|
|
}
|