/* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter#Compatibility

   under MIT license / public domain, see

   https://developer.mozilla.org/en-US/docs/MDN/About#Copyrights_and_licenses */

if (!Array.prototype.filter)

{

    Array.prototype.filter = function(fun /*, thisArg */)

    {

        "use strict";

        if (this === void 0 || this === null)

            throw new TypeError();

        var t = Object(this);

        var len = t.length >>> 0;

        if (typeof fun !== "function")

            throw new TypeError();

        var res = [];

        var thisArg = arguments.length >= 2 ? arguments[1] : void 0;

        for (var i = 0; i < len; i++)

        {

            if (i in t)

            {

                var val = t[i];

                // NOTE: Technically this should Object.defineProperty at

                //       the next index, as push can be affected by

                //       properties on Object.prototype and Array.prototype.

                //       But that method's new, and collisions should be

                //       rare, so use the more-compatible alternative.

                if (fun.call(thisArg, val, i, t))

                    res.push(val);

            }

        }

        return res;

    };

}