luhn-generator
Version:
A generator of numbers that passes the validation of Luhn algorithm or Luhn formula, also known as the 'modulus 10' or 'mod 10' algorithm
70 lines (67 loc) • 2.78 kB
JavaScript
'use strict';
var LIBRARY = require('./_library');
var $export = require('./_export');
var redefine = require('./_redefine');
var hide = require('./_hide');
var Iterators = require('./_iterators');
var $iterCreate = require('./_iter-create');
var setToStringTag = require('./_set-to-string-tag');
var getPrototypeOf = require('./_object-gpo');
var ITERATOR = require('./_wks')('iterator');
var BUGGY = !([].keys && 'next' in [].keys()); // Safari has buggy iterators w/o `next`
var FF_ITERATOR = '@@iterator';
var KEYS = 'keys';
var VALUES = 'values';
var returnThis = function () { return this; };
module.exports = function (Base, NAME, Constructor, next, DEFAULT, IS_SET, FORCED) {
$iterCreate(Constructor, NAME, next);
var getMethod = function (kind) {
if (!BUGGY && kind in proto) return proto[kind];
switch (kind) {
case KEYS: return function keys() { return new Constructor(this, kind); };
case VALUES: return function values() { return new Constructor(this, kind); };
} return function entries() { return new Constructor(this, kind); };
};
var TAG = NAME + ' Iterator';
var DEF_VALUES = DEFAULT == VALUES;
var VALUES_BUG = false;
var proto = Base.prototype;
var $native = proto[ITERATOR] || proto[FF_ITERATOR] || DEFAULT && proto[DEFAULT];
var $default = $native || getMethod(DEFAULT);
var $entries = DEFAULT ? !DEF_VALUES ? $default : getMethod('entries') : undefined;
var $anyNative = NAME == 'Array' ? proto.entries || $native : $native;
var methods, key, IteratorPrototype;
// Fix native
if ($anyNative) {
IteratorPrototype = getPrototypeOf($anyNative.call(new Base()));
if (IteratorPrototype !== Object.prototype && IteratorPrototype.next) {
// Set @@toStringTag to native iterators
setToStringTag(IteratorPrototype, TAG, true);
// fix for some old engines
if (!LIBRARY && typeof IteratorPrototype[ITERATOR] != 'function') hide(IteratorPrototype, ITERATOR, returnThis);
}
}
// fix Array#{values, @@iterator}.name in V8 / FF
if (DEF_VALUES && $native && $native.name !== VALUES) {
VALUES_BUG = true;
$default = function values() { return $native.call(this); };
}
// Define iterator
if ((!LIBRARY || FORCED) && (BUGGY || VALUES_BUG || !proto[ITERATOR])) {
hide(proto, ITERATOR, $default);
}
// Plug for library
Iterators[NAME] = $default;
Iterators[TAG] = returnThis;
if (DEFAULT) {
methods = {
values: DEF_VALUES ? $default : getMethod(VALUES),
keys: IS_SET ? $default : getMethod(KEYS),
entries: $entries
};
if (FORCED) for (key in methods) {
if (!(key in proto)) redefine(proto, key, methods[key]);
} else $export($export.P + $export.F * (BUGGY || VALUES_BUG), NAME, methods);
}
return methods;
};