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luhn-generator

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A generator of numbers that passes the validation of Luhn algorithm or Luhn formula, also known as the 'modulus 10' or 'mod 10' algorithm

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var bind = require('../internals/function-bind-context'); var IndexedObject = require('../internals/indexed-object'); var toObject = require('../internals/to-object'); var toLength = require('../internals/to-length'); var arraySpeciesCreate = require('../internals/array-species-create'); var push = [].push; // `Array.prototype.{ forEach, map, filter, some, every, find, findIndex }` methods implementation var createMethod = function (TYPE) { var IS_MAP = TYPE == 1; var IS_FILTER = TYPE == 2; var IS_SOME = TYPE == 3; var IS_EVERY = TYPE == 4; var IS_FIND_INDEX = TYPE == 6; var NO_HOLES = TYPE == 5 || IS_FIND_INDEX; return function ($this, callbackfn, that, specificCreate) { var O = toObject($this); var self = IndexedObject(O); var boundFunction = bind(callbackfn, that, 3); var length = toLength(self.length); var index = 0; var create = specificCreate || arraySpeciesCreate; var target = IS_MAP ? create($this, length) : IS_FILTER ? create($this, 0) : undefined; var value, result; for (;length > index; index++) if (NO_HOLES || index in self) { value = self[index]; result = boundFunction(value, index, O); if (TYPE) { if (IS_MAP) target[index] = result; // map else if (result) switch (TYPE) { case 3: return true; // some case 5: return value; // find case 6: return index; // findIndex case 2: push.call(target, value); // filter } else if (IS_EVERY) return false; // every } } return IS_FIND_INDEX ? -1 : IS_SOME || IS_EVERY ? IS_EVERY : target; }; }; module.exports = { // `Array.prototype.forEach` method // https://tc39.github.io/ecma262/#sec-array.prototype.foreach forEach: createMethod(0), // `Array.prototype.map` method // https://tc39.github.io/ecma262/#sec-array.prototype.map map: createMethod(1), // `Array.prototype.filter` method // https://tc39.github.io/ecma262/#sec-array.prototype.filter filter: createMethod(2), // `Array.prototype.some` method // https://tc39.github.io/ecma262/#sec-array.prototype.some some: createMethod(3), // `Array.prototype.every` method // https://tc39.github.io/ecma262/#sec-array.prototype.every every: createMethod(4), // `Array.prototype.find` method // https://tc39.github.io/ecma262/#sec-array.prototype.find find: createMethod(5), // `Array.prototype.findIndex` method // https://tc39.github.io/ecma262/#sec-array.prototype.findIndex findIndex: createMethod(6) };