JS Promise的简单实现

//constructorvar Promise = function() {    this.callbacks = [];}Promise.prototype = {    construct: Promise,    resolve: function(result) {        this.complete("resolve", result);    },    reject: function(result) {        this.complete("reject", result);    },    complete: function(type, result) {        while (this.callbacks[0]) {            this.callbacks.shift()[type](result);        }    },    then: function(successHandler, failedHandler) {        this.callbacks.push({            resolve: successHandler,            reject: failedHandler        });        return this;    }}// testvar promise = new Promise();