Anders Hejlsberg: Introducing Async – Simplifying Asynchronous Programming

Async CTP link doesn't work

oh, they are doing it for C# too, when this emerges on PDC08 IIRC its a VB language feature, oh right they are co-evolving now, mmm...

uhhh...maybe its just my first sight of these stuff are demoed in vb language ... heh

busy watching PDC now ...

Iterators and async, IEnumerable and IObservable, state machines and duality, oh yes, LINQs abound.

Great explanation from Anders.

Isn't it amazing how how much easier it is to comprehend a complex subjecct when presented by someone with so much enthusiasm?

Great work Anders & Team. Can't wait to see what you attack next

the async stuff sounds great. Any plans in C# to make dependency properties a part of the language? Having to understand and debug dependency properties made learning WPF kind of hard for me.

Erm... how come no comment on IObservable? Seriously guys, you talked about IEnumerable, iterators and all the good stuff, but not a word on Rx? What hath thou done Charles? *rant*

I know you can't have try { ... } finally { ...} or using (...) { ... } inside an iterator in .NET 2.0. Do asynchronous methods have the same problem?

this is what I have throughout my program and it is very annoying just like Mr. Anders mentioned, inverse flow of control with 2 delegate callbacks one for regular return, the other one for exception. 
EventHandler<T> failureHandler = null;
EventHandler<T> successHandler = null;
 
failureHandler = (s,ea) =>
{
    obj.FailureEvent -= failureHandler;
    obj.SuccessEvent -= successHandler;
    // handle failed state
   ...
};
 
successHandler = (s,ea) =>
{
    obj.FailureEvent -= failureHandler;
    obj.SuccessEvent -= successHandler;
    // handle success state
    ...
};
 
obj.SuccessEvent += successHandler;
obj.FailureEvent += failureHandler;
obj.RunAsync();
I am very looking forward to this feature.
 

Hmm, I guess line break (carriage return) is not an option.

Does anyone know when this async stuff gets offically released? I guess my question is whether Async CTP is reliable enough to be incorporated into my product code.

Fantastic stuff, I need to read up on F#'s async some more and look at the TPL!

Did anyone else find themselves checking their inbox while watching that video ?

For some reason, I really like this guy's attitude. Brilliance is one thing. Addressing the credit is one thing. But, something else makes me really put me in comfort with him. Maybe he makes it easier to understand for me. Or maybe some other reasons. So, I hope he continues his good work in MS and I hope MS values his work too. After all, I hope to use his stuff for a long long time.

@ elmer. Absolutely. But then I realized I didn't have Windows Live Mail open. Nice explanation Mr. Anders.

@elmer:Nope.

I don't mean to be mean, but Anders did dodge the final question. In having asynchrony done by the compiler you will lose control, so... how well is it optimised, what efficiency compromises are inherent in a solution that cannot be "hand-coded". Hejlsberg just turned around the question and answered it as if it had been about the comparatively minimal creeping featurism of the syntax.

Hmm.. I think this is more for the VB guys, its already easy using anonymous methods from C# for which this syntax is just a shortcut (I am guessing):
someThread.BeginInvoke(new Action(delegate() 
 {
  // do something
});
 
 

No Async love for Express editions? I tried installing the CTP (I have Visual Studio Web Developer and C# Express installed) but could not located the Async DLLs after.

What if ALL functions will be decared async automatically? What are the implications of that?

@Clint: Thanks.

@ecofriend: Express SKUs are not supported. you can download one of the trial version of Visual Studio from here http://www.microsoft.com/visualstudio/en-us/download

Why did you choose to implement it so that an await statement can only be resumed once? For example you can't implement await on List (or most other monads for that matter):
 
async List<int> CartesianProduct(List<int> A, List<int> B){
    var a = await A;
    var b = await B;
    return new Tuple(a,b);
}

 
Great work ! 

I'm sort of sad Because of parallel and async tasks I had an argument to start learning F#. Now I have only wait for new C#  

@Charles:Yup you are right, I just getting into current C# and .Net4, till I will get into f# there will be next c# it is so so little time to learn it