JS Queue (with support for a delay)

queue.js

var queue = function () {
        this.items = [];
        this.timer = null;
    };

queue.prototype = {
    add: function (item) {
        var self = this;
        self.items.push(item);
    },

    flush: function () {
        var self = this;

        if (self.timer) {
            return;
        }

        while (self.items.length) {
            var fn = self.items.shift();

            if (fn.toString().indexOf('delay:') !== -1) {
                var ms = Number(fn.split(':')[1]);

                self.timer = setTimeout(function () {
                    self.timer = null;
                    self.flush();
                }, ms);

                return;
            }

            fn();
        }
    }
};