Javascript：自己写异步流程编程框架

背景

自从NodeJs出来以后，异步编程便更加系统化和框架话了，为了应对异步编程框架带来的深层嵌套问题，社区也出现了异步流程编程框架，本文主要对异步流程框架做一个简单的解析。

现配代码了

 var Asy = function () {
 };

 Asy.start = function (action, success, failure) {
     var asy = new Asy();
     asy._addAction(action, success, failure);

     return asy;
 }

 Asy.emptyFun = function () { };

 Asy.prototype.then = function (action, success, failure) {
     var me = this;

     me._addAction(action, success, failure);

     return me;
 };

 Asy.prototype._addAction = function (action, success, failure) {
     var me = this;

     me._actions = me._actions || [];

     me._actions.push({
         action: action || Asy.emptyFun,
         success: success || Asy.emptyFun,
         failure: failure || Asy.emptyFun
     });
 };

 Asy.prototype.execute = function () {
     var me = this;

     var length = me._actions.length;

     var resultFun = function () {
         var args = Array.prototype.slice.call(arguments)
                                   .concat([me._actions[length - 1].success, me._actions[length - 1].failure])

         me._actions[length - 1].action.apply(null, args);
     };

     for (var i = me._actions.length - 2; i >= 0 ; i--) {
         (function (action) {
             var oldResultFun = resultFun;

             resultFun = function () {
                 var newSuccess = function () {
                     var args = Array.prototype.slice.call(arguments);
                     action.success.apply(null, args);
                     oldResultFun.apply(null, args);
                 };

                 var args = Array.prototype.slice.call(arguments)
                                           .concat([newSuccess, action.failure]);

                 action.action.apply(null, args);
             };
         })(me._actions[i]);
     };

     var args = Array.prototype.slice.call(arguments);
     resultFun.apply(null, args);
 }

 var testAsyFun = function (i, success, failure) {
     setTimeout(function () {
         i = i + 1;

         success(i);
     }, 2000);
 };

 Asy
    .start(testAsyFun, function (i) {
        console.log("A:" + i);
    })
    .then(testAsyFun, function (i) {
        console.log("B:" + i)
    })
    .then(testAsyFun, function (i) {
        console.log("C:" + i)
    })
    //.wait([testAsyFun], [testAsyFun], function () {

    //})
    .execute(1);