Playing at a simple app framework

framework.js

(function (window) {

    var document = window.document;

    var getType = function (thing) {
            return Object.prototype.toString.call(thing).match(/\s(\w+)/)[1].toLowerCase();
        };

    var getIsType = function (type) {
            return (function (thing) {
                return getType(thing) === type;
            });
        };

    var isObject = getIsType('object');
    var isArray = getIsType('array');
    var isFunction = getIsType('function');

    var getParams = function () {
            var search, pairs, pair, idx, val, params, i, l;

            search = document.location.search.replace('?', '');
            pairs = search.split('&');
            params = {};

            for (i = 0, l = pairs.length; i < l; i++) {
                pair = pairs[i].split('=');
                idx = pair[0];
                val = pair[1];
                if (params.hasOwnProperty(idx)) {
                    if (isArray(params[idx])) {
                        params[idx].push(val);
                    } else {
                        params[idx] = [params[idx], val];
                    }
                } else {
                    params[idx] = val;
                }
            }

            return params;
        };

    var globalRoutes = {};

    var addRoutes = function (routes) {
            var i;

            if (isObject(routes)) {
                for (i in routes) {
                    if (routes.hasOwnProperty(i)) {
                        globalRoutes[i] = routes[i];
                    }
                }
            }
        };

    var router = function () {
            var loc, route, params;

            loc = document.location;
            route = loc.pathname;
            params = getParams();

            if (isFunction(globalRoutes[route])) {
                globalRoutes[route].call(this, params);
            }
        };

    window.addRoutes = addRoutes;

})(this);