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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 anObject = require('../internals/an-object'); var isArrayIteratorMethod = require('../internals/is-array-iterator-method'); var toLength = require('../internals/to-length'); var bind = require('../internals/function-bind-context'); var getIteratorMethod = require('../internals/get-iterator-method'); var iteratorClose = require('../internals/iterator-close'); var Result = function (stopped, result) { this.stopped = stopped; this.result = result; }; module.exports = function (iterable, unboundFunction, options) { var that = options && options.that; var AS_ENTRIES = !!(options && options.AS_ENTRIES); var IS_ITERATOR = !!(options && options.IS_ITERATOR); var INTERRUPTED = !!(options && options.INTERRUPTED); var fn = bind(unboundFunction, that, 1 + AS_ENTRIES + INTERRUPTED); var iterator, iterFn, index, length, result, next, step; var stop = function (condition) { if (iterator) iteratorClose(iterator); return new Result(true, condition); }; var callFn = function (value) { if (AS_ENTRIES) { anObject(value); return INTERRUPTED ? fn(value[0], value[1], stop) : fn(value[0], value[1]); } return INTERRUPTED ? fn(value, stop) : fn(value); }; if (IS_ITERATOR) { iterator = iterable; } else { iterFn = getIteratorMethod(iterable); if (typeof iterFn != 'function') throw TypeError('Target is not iterable'); // optimisation for array iterators if (isArrayIteratorMethod(iterFn)) { for (index = 0, length = toLength(iterable.length); length > index; index++) { result = callFn(iterable[index]); if (result && result instanceof Result) return result; } return new Result(false); } iterator = iterFn.call(iterable); } next = iterator.next; while (!(step = next.call(iterator)).done) { try { result = callFn(step.value); } catch (error) { iteratorClose(iterator); throw error; } if (typeof result == 'object' && result && result instanceof Result) return result; } return new Result(false); };