8000 added shuffle to list · immutable-js/immutable-js@98c5923 · GitHub
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mazertymazerty
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added shuffle to list
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‎__tests__/List.ts

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@@ -1,5 +1,6 @@
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import { fromJS, List, Map, Range, Seq, Set } from 'immutable';
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import * as jasmineCheck from 'jasmine-check';
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import { create as createSeed } from 'random-seed';
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jasmineCheck.install();
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@@ -1012,6 +1013,31 @@ describe('List', () => {
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});
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});
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describe('when shuffling', () => {
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const list = List.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
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it('should work when empty', () => {
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expect(List().shuffle()).toStrictEqual(List());
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});
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it('should work with Math.random', () => {
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expect(list.shuffle().sort()).toStrictEqual(list);
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});
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it('should work with a pseudo random number generator', () => {
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const seed = createSeed('lorem ipsum');
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const random = () => seed.random();
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expect(list.shuffle(random)).toStrictEqual(
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List.of(5, 2, 4, 7, 6, 3, 10, 1, 9, 8)
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);
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expect(list.shuffle(random)).toStrictEqual(
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List.of(1, 6, 2, 3, 9, 7, 4, 10, 5, 8)
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);
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expect(list.shuffle(random)).toStrictEqual(
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List.of(6, 1, 8, 10, 9, 5, 4, 7, 3, 2)
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);
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});
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});
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describe('Iterator', () => {
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const pInt = gen.posInt;
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‎package-lock.json

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‎package.json

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"@size-limit/preset-small-lib": "^8.2.6",
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"@types/jest": "^29.0.0",
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"@types/prismjs": "^1.26.3",
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"@types/random-seed": "0.3.5",
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"@types/react": "17.0.11",
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"benchmark": "2.1.4",
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"colors": "1.4.0",
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"npm-run-all": "4.1.5",
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"prettier": "^3.5.0",
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"prismjs": "^1.29.0",
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"random-seed": "0.3.0",
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"react": "^18.2.0",
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"react-dom": "^18.2.0",
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"rimraf": "2.7.1",

‎src/List.js

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@@ -140,6 +140,22 @@ export class List extends IndexedCollection {
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return setListBounds(this, 1);
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}
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shuffle(random = Math.random) {
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return this.withMutations((mutable) => {
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let current = mutable.size,
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destination,
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tmp;
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while (current) {
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destination = Math.floor(random() * current--);
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tmp = mutable.get(destination);
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mutable.set(destination, mutable.get(current));
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mutable.set(current, tmp);
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}
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});
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}
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// @pragma Composition
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concat(/*...collections*/) {

‎type-definitions/immutable.d.ts

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@@ -758,6 +758,14 @@ declare namespace Immutable {
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zipper: (...values: Array<unknown>) => Z,
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...collections: Array<Collection<unknown, unknown>>
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): List<Z>;
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/**
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* Returns a new List with its values shuffled thanks to the
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* [Fisher–Yates](https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle)
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* algorithm.
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* It uses Math.random, but you can provide your own random number generator.
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*/
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shuffle(random?: () => number): this;
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}
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/**

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