co

Could someone help me understand the differences between using Koa.js and Bluebird.js with ES6 Harmony. Specifically, how does co( function * () { //stuff } ); compare to, Promise.coroutine( function * () { //stuff } ); It just seems Koa should be using Bluebird and not recreating the wheel. What's different? For now the difference is that Koa allows yielding more than just promises. However a feature is being added that allows not only yielding callbacks, thunks etc but any arbitrary thing that comes to your mind. Bluebird is also the fastest. So after this version koa should be just using

I want to hold the error from func() reject , not direct to onError() by choise, Before I always let func() resolve , and determine return result after yield func() , if I want to direct to onError() use throw ..; Wondering any better idea I can just let func() reject but detemire after yield func() , direct to onError() or not co(function* () { yield func(); // if reject catch here, not direct to onError yield func(); // if reject don't catch here just direct to onError }).then(function (response) { response = JSON.stringify(response); res.send(response); }, function (err) { onError(err); });

I am new to nodejs. Here, I want to avoid callback using Co generators with promises. But when I execute this code, it only executes first yield or does not assign the result of get function to processedData0 variable. How to solve this ? co(function *() { console.log("hello"); try{ console.log("hello"); var processedData0= yield Promise.promisify(get); //console.log("hello"); var processedData1 = yield Promise.promisify(abc1)(processedData0); //console.log("hello2"); var processedData2 = yield Promise.promisify(xyz)(processedData1); //console.log("hello3"); var processedData3 = yield Promise