/**

     * 迷你版的deferred

     */

    function Deferred(func) {

        if (this instanceof Deferred === false) {

            return new Deferred(func)

        }

        var tuple = [];

        var promise = {

            resolve: function() {

                var t = tuple.shift(),

                    n;

                t && (n = t.apply(null, arguments), n instanceof Deferred && (n.tuple = tuple));

            },

            then: function(n) {

                return tuple.push(n), this;

            }

        }

        if (func) {

            func.call(promise, promise.resolve);

        }

        return promise;

    };

var d = new Deferred();

    setTimeout(function() {

        d.resolve('aaaa')

    }, 500)

    d.then(function(bbb){

        console.log(bbb)

    })

Deferred(function(resolve) {

    resolve('aaaa')

}).then(function(bbb) {

    console.log(bbb)

})