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js-combinatorics

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Simple combinatorics like power set, combination, and permutation in JavaScript

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/* * use mocha to test me * http://visionmedia.github.com/mocha/ */ var assert, Combinatorics; if (this['window'] !== this) { assert = require("assert"); Combinatorics = require('../.'); } var is_deeply = function (a, e, m) { return function () { assert.equal(JSON.stringify(a), JSON.stringify(e), m) } }; var IT=function(t,f){it(JSON.stringify(t),f)}; // mocha 3 describe('Combinatorics.permutationCombination', function () { var a = 'a'.split(''), c = Combinatorics.permutationCombination(a); IT(a, is_deeply(c.toArray(), [ ["a"] ])); IT(c + 0, is_deeply(c + 0, c.toArray().length)); IT(c.length, is_deeply(c.length, c.toArray().length)); a = 'ab'.split(''); c = Combinatorics.permutationCombination(a); IT(a, is_deeply(c.toArray(), [ ["a"], ["b"], ["a", "b"], ["b", "a"] ])); IT(a, is_deeply(c.filter(function(a){ return a[0] === 'a'}), [ ["a"], ["a", "b"] ])); IT(c + 0, is_deeply(c + 0, c.toArray().length)); IT(c.length, is_deeply(c.length, c.toArray().length)); // Testing lazy filter c = Combinatorics.permutationCombination(a).lazyFilter(function(a){ return a[0] === 'a' }); IT(a, is_deeply(c.toArray(), [ ["a"], ["a", "b"] ])); // And resetting the lazy filter c.lazyFilter(); IT(a, is_deeply(c.toArray(), [ ["a"], ["b"], ["a", "b"], ["b", "a"] ])); a = 'abc'.split(''); c = Combinatorics.permutationCombination(a); IT(a, is_deeply(c.toArray(), [ ["a"], ["b"], ["c"], ["a","b"], ["b","a"], ["a","c"], ["c","a"], ["b","c"], ["c","b"], ["a","b","c"], ["a","c","b"], ["b","a","c"], ["b","c","a"], ["c","a","b"], ["c","b","a"] ])); IT(c + 0, is_deeply(c + 0, c.toArray().length)); IT(c.length, is_deeply(c.length, c.toArray().length)); a = 'abcd'.split(''); c = Combinatorics.permutationCombination(a); IT(a, is_deeply(c.toArray(), [ ["a"], ["b"], ["c"], ["d"], ["a","b"], ["b","a"], ["a","c"], ["c","a"], ["b","c"], ["c","b"], ["a","d"], ["d","a"], ["b","d"], ["d","b"], ["c","d"], ["d","c"], ["a","b","c"], ["a","c","b"], ["b","a","c"], ["b","c","a"], ["c","a","b"], ["c","b","a"], ["a","b","d"], ["a","d","b"], ["b","a","d"], ["b","d","a"], ["d","a","b"], ["d","b","a"], ["a","c","d"], ["a","d","c"], ["c","a","d"], ["c","d","a"], ["d","a","c"], ["d","c","a"], ["b","c","d"], ["b","d","c"], ["c","b","d"], ["c","d","b"], ["d","b","c"], ["d","c","b"], ["a","b","c","d"], ["a","b","d","c"], ["a","c","b","d"], ["a","c","d","b"], ["a","d","b","c"], ["a","d","c","b"], ["b","a","c","d"], ["b","a","d","c"], ["b","c","a","d"], ["b","c","d","a"], ["b","d","a","c"], ["b","d","c","a"], ["c","a","b","d"], ["c","a","d","b"], ["c","b","a","d"], ["c","b","d","a"], ["c","d","a","b"], ["c","d","b","a"], ["d","a","b","c"], ["d","a","c","b"], ["d","b","a","c"], ["d","b","c","a"], ["d","c","a","b"], ["d","c","b","a"] ])); IT(c + 0, is_deeply(c + 0, c.toArray().length)); IT(c.length, is_deeply(c.length, c.toArray().length)); a = 'ab'.split(''); // Testing lazy map c = Combinatorics.permutationCombination(a).lazyMap(function(a){ if (a[0] === 'a') { a[0] = 'z' } return a; }); IT(a, is_deeply(c.toArray(), [ ["z"], ["b"], ["z", "b"], ["b", "a"] ])); // And resetting the lazy filter c.lazyMap(); IT(a, is_deeply(c.toArray(), [ ["a"], ["b"], ["a", "b"], ["b", "a"] ])); // Testing .reduce var r = function(a, e, i){return a + i + ":" + e + ";"}; var s = c.toArray().reduce(r, ""); IT( s + " // c.reduce", is_deeply(s, c.reduce(r, ""))); });