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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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'use strict'; var charAt = require('../internals/string-multibyte').charAt; var InternalStateModule = require('../internals/internal-state'); var defineIterator = require('../internals/define-iterator'); var STRING_ITERATOR = 'String Iterator'; var setInternalState = InternalStateModule.set; var getInternalState = InternalStateModule.getterFor(STRING_ITERATOR); // `String.prototype[@@iterator]` method // https://tc39.github.io/ecma262/#sec-string.prototype-@@iterator defineIterator(String, 'String', function (iterated) { setInternalState(this, { type: STRING_ITERATOR, string: String(iterated), index: 0 }); // `%StringIteratorPrototype%.next` method // https://tc39.github.io/ecma262/#sec-%stringiteratorprototype%.next }, function next() { var state = getInternalState(this); var string = state.string; var index = state.index; var point; if (index >= string.length) return { value: undefined, done: true }; point = charAt(string, index); state.index += point.length; return { value: point, done: false }; });