"F# async on the server side" - node.fs in waiting? | Hacker News Reader

"F# async on the server side" - node.fs in waiting?

lorgonblog.wordpress.com

The article compared "async" C# to async F# and makes the claim that F# is better because of the lighter syntax. The only problem is that they're using the wrong version of C#. C# is expected to get the same async feature in the next version. Version 4 brought dynamic features to C# and completely changed the language. Version 5 is expected to bring async and change how people use C# again.

It's really slick and MS should really be commended for their work on it. It makes writing asynchronous code as straightforward as writing regular code. No crazy callbacks. That's what is so great about the CLI. All the .NET languages get an upgrade when the CLI gets an upgrade. All the work done to support Python and Ruby on .NET led to the dynamic and functional features of C# 4.

But F# is stable, officially supported (as one of the three - VB.Net, C#, F#) - and comes with this _now_.

I like the language a lot and think that it has great potential. It's a shame that there's so little weight behind it so far, ignoring niche markets (banks for example).

It took Python and Ruby over 10 years to break into the "big time". F#, while really cool, still doesn't have its "killer app" to drive adoption.

Keep in mind, F# only just became a first-class language in the MS suite with VS2010. Give it time.

And they didn't release an f# express, you have to install shell and then install the f# runtime on top of that, instead of just one simple install the way c# and vb.net is. It isn't the end of the world but seems stupid if they want to increase adoption of the language.

That's because it's not an Express -- i.e. stripped down -- version. It's the full package. You can easily use F# from the command line, as you can with Ruby and Python. F# is also open sourced [1], so you can also build and run it on *nix with Mono [2]. Why would I want an Express edition?

[1] https://github.com/fsharp/fsharp [2] http://chrismarinos.com/f-on-ubuntu-linux-with-mono-and-mono...

The Async CTP framework brings a lot of that functionality now, and from my personal experience it seems pretty stable.

It's well worth checking out if you want a better async experience in C#, but I still find that I have to write a lot of wrapper methods to make existing classes play nicely.

http://msdn.microsoft.com/en-us/vstudio/gg316360

The F# async implementation isn't just lighter syntax, it's a fully baked-in approach for building complicated computations. You can find more examples around the web, many of which I have rolled into the FSharp.Monad library [1].

[1] http://github.com/panesofglass/FSharp.Monad

(I don't follow C# 5 but inability to generate tail calls in C# seems to be a significant issue:

http://fsharpnews.blogspot.com/2010/12/performance-related-f...

(comments)

http://msmvps.com/blogs/jon_skeet/archive/2010/10/29/initial...

The C#/VB async feature looks like a variation of the F# feature and seems to derive from it. The C# team work pretty closely with the F# team. There is a good comparison here of the C# and F# features here: http://tomasp.net/blog/csharp-fsharp-async-intro.aspx. There's a paper on the F# asynchronous model mentioned at the end.

As soon as I saw node.fs, I knew it had to be done in F# (preferably with Mono). It's just too good not to be done. All the goodness of functional-reactive servers with the .NET pantheon of libraries thrown in.

I especially like the code/time comparisons at the bottom. For those C# and other .NET guys, yes, you can do the same thing in any .NET language. That's not the point. What F# brings is the ability to think and write code in a quicker, more concise manner that's also more error-free. Modern coding environments are more and more lending themselves to FP.

It would be great to see an F# aync http server combined with something like WebSharper(which allows writing a lot of javascript in F#).

http://websharper.com/samples/Canvas

http://websharper.com/samples/WebGL

Get it to work on Mono and it would be Mono and F#'s killer app(stack).

Working on it... ;)

http://github.com/fractureio/fracture

NB I found this after listening to a podcast about IronJS, during which Fredrik Holmström mentioned that F# would be a much better starting point for an async http server.

He wrote this blog post today.

http://ironjs.wordpress.com/2011/06/22/my-gripes-with-javasc...

cough

There are things like https://github.com/panesofglass/frack already. That's not the only one. This entire approach running on the stack and frameworks it can is a massive deal, and running silent at present.

For semi-related further reading, here is the second in a blog series extending async F# in the context of developing GUIs:

http://tomasp.net/blog/safe-gui-async.aspx

Reply on news.ycombinator.com