Somasegar's WebLog

1st :D

Soma, pls fix the code examples. It would be great if one could just copy/paste them in VS.

Async example doesn't have the full name of classes specified. Does one still use 'open' keyword to import namespaces?

And the ray tracer code in text would be nice.

BTW when is VS beta 2 coming out? And what is the current estimate for RTM date?

OK, this took just a few hours, but now I have the 2nd example working. Fsharp PowerPack from CodePlex is required. The compiler gives a few warnings.

#light

open System

open System.IO

open System.Net

let http url =

   async { let req =  WebRequest.Create (url :> string)

           let! resp = req.AsyncGetResponse()

           let stream = resp.GetResponseStream()

           let reader = new StreamReader(stream)

           let! contents = reader.AsyncReadToEnd()

           return contents }

let sites = ["http://bing.com"; "http://microsoft.com";

            "http://msdn.com"; "http://msnbc.com"]

let htmlOfSites =

   Async.Parallel [for site in sites -> http(site)]

   |> Async.RunSynchronously

printfn "html: %a" output_any htmlOfSites

Console.ReadKey()

Hi John -

That's right, the async example requires the 3 open declarations you mention and the F# PowerPack.

The raytracer sample is similar to the F# Raytracer in the Parallel Samples for .Net 4.0 at http://code.msdn.microsoft.com/ParExtSamples.

More F# samples also at http://fsharp.net.  

It is nice to see F# moving along and being included with the other main stream languages. What I would like see is how to integrate it with other languages. A Visual Studio solution with a C# project referencing a F# project. Correct me if I'm wrong but I see F# as a complementary language. F# is a language to handle complex math easier than other languages but not to build a complete application with. One would use F# to build a library of intense math function. These math functions in an assembly would be referenced and used in a WPF, XNA, or Silverlight application written in C# or VB. If that is the case are there any examples showing that type of integration?  I see the ray tracing application but it looks to be bolted to Visual Studio. How could I build a Windows Form or WPF application to drive the ray tracing logic via C#? Maybe a game demo built with XNA using an F# library for the physic logic?

SomeONe:

For the most part you can expose classes and interfaces in your F# project and instantiate them, call their methods, subclass them etc. from C# like any other .NET class library.  If you expose types based on F#-specific features like pattern matching, workflows or units of measure, you can still use them from other languages but you'll have to know a bit about how those features are implemented and you won't get the benefits of them.

The initial release of F# will (as far as I know) not be quite on a par with C# or VB.NET.  You don't automatically get it in th GAC, so in some deployment scenarios you have extra work to do.

My guess is that a lot of people are going to try the waters and really like them.  The code can, in some cases, just be so clean, lean and right that it will become the language of choice for some.

I'm really hoping that in a fairly short time it will become fully first class and just be installed everywhere like the main languages currently are.

Congratulations to Don Syme, and all those involved at Microsoft and in the community, in the brillant work to bring F# to this point.

I'm looking forward to a bright F#UN (read that BIG F# FUN) future. Using VS, F# and .NET to leverage the power of manycore CPUs and GPUs for visualization.

The future is bright,now and F#!

contextfree:

I know it can be done because that is one of the great things about .NET and the CIL/CLR . My question was more of where is a real world example of it being done. Not just the "in theory" discussions because it is .NET. Prove it by example.

Mike Gale:

IMHO I don't believe F# "will become fully first class (language)"

That is why there needs to be some kind of integration between the two. C# or VB.Net will be the first class language driving the UI/UX (if that be WinForm, WPF, or XNA, etc…) calling function in an F# library/assebmly.

Unless there are demos showing a complete application (menus, multiple forms, dialog boxes, tabs, combo box, etc…) written in F# driving the UI/UX and handling UI Events that otherwise would have been written in C# or VB.net. Or maybe a UI framework written completely in F# like MVC or MVVM or MVM? I'm thinking that is what C# and Vb.Net is for not F#.

I'm just wondering in the real world for consumer applications where F# fits. Or is meant as a lab tool for the Engineers and Scientist and is used in house.

I guess I know now what I need to work on. A C#/F# application.

SomeOne (sic):

Your comment about first class misses what I'm saying.

In the narrow meaning I'm using here it becomes first class when it get's automatically distributed the same way that C# and VB.NET are "just there".

Mike Gale:

Got it, and from what I hear VS2010 it will be there. Even with the May 2009 Community Technology Preview.

To put the theory to practice is easy as alluded to in previous post. I knew and know it I just want to see it. The question as far as namespace, what an object name would be, what would I get returned from a function, do I need to reference F# in my C# all came to light.

I did the following got the code from http://fsharpsamples.codeplex.com/

1. Downloaded the May 2009 CTP.

2. Created a C# WPF application/solution.

3. Add a new F# Library Project

4. In this case I need to reference FSharp.Core in my c# project.

5. Made a reference in the C# to the F# project.

6. Copied the Fractal.fs from the samples to the F# project.

7. Copied the XAML from the sample to my C# application

8. Added to the XAML x:Class="CandFWPF.Window1"

9. Then add an Window_Loaded event handler coverted the F# to C#.

var br = new SolidColorBrush();

br.Color = Color.FromRgb(255, 255, 255);

var x = Fractal.CreateFractal();

this.fractal.Content = new GeometryModel3D(x.Item2, new DiffuseMaterial(br));

This is the line doing the call out to the F# assembly. Answers to questions, no name space, the class name is the file name. Function are static.

var x = Fractal.CreateFractal();

Now on to a bigger challenge QuotationsVisualizer. There seems to be a lot of code to write and handle GUI stuff. That is not math related and looks to me cumbersome in F#. I get complaints that at times C# is hard to read and interpret into English statement. Even with form designers and other GUI tools. I would hate for those people to try and read these:

member this.OpenFsAssembly () =

  let opf = new OpenFileDialog()

  opf.Filter <- "F# assemblies|*.dll;*.exe";

  match opf.ShowDialog(this) with

    | DialogResult.OK ->

        ResolveAssemblyDefinitions(opf.FileName)

          ( fun t ->

              let nd = new TreeNode(t.Name, 1, 1)

              ignore(exprTree.Nodes.Add(nd))

              nd )

          ( fun ndType mi exp ->

              let fn = new Text.StringBuilder()

              ignore(fn.AppendFormat("Loaded from assembly: {0}\r\n", mi.DeclaringType.Assembly.FullName));

              ignore(fn.Append("Declared in type: "));

              if (mi.DeclaringType.Namespace <> null) then ignore(fn.AppendFormat("{0}.", mi.DeclaringType.Namespace))

              ignore(fn.Append(mi.DeclaringType.Name));

              let nd = this.AddQuotationNode mi.Name (fn.ToString()) exp

              ignore(ndType.Nodes.Add(nd)) )          

    | _ -> ()

or this to build a Tree and assign properies and event handler:

  exprTree.Left <- 32

  exprTree.Width <- 200

  exprTree.Height <- 268

  exprTree.Top <- 288

  exprTree.HideSelection <- false

  exprTree.AfterSelect.Add(fun e ->

    if (e.Node.Tag <> null) then

      this.SelectPanel(e.Node.Tag :?> QuotationPanel))

Hi There,

This is very cool feature.

Thanks for letting us know this.

Thanks,

Thani

Will there be a F# Express product?

CA Reed -

There are no plans at this time for an F# Express with VS2010.  There will definitely continue to be free development tools for F# available though.

Created a Class Library (dll) in F# using VS 08 with the F# CTP October release.

Tried using the Assembly from VS2010 beta 1, after referencing the library (dll file generated by the F# Compiler) I can access the Namespaces in the library, but these namespaces vanish once I try to build the project and I can't henceforth access the referenced F# library.

It used to work with assemblies I built with the F# May CTP release, this problem started after i installed the October CTP

What could be wrong.

Thanks in advance.

Hi Adenegan -

Each F# CTP releases is matched with a Beta release of VS2010.  The October F# CTP can build libraries which can be be used in VS2010 Beta2.  If you still need to work with VS2010 Beta1, you'll want to contiue using the matching F# May CTP.  If you can, I'd encourage you to move to VS2010 Beta2, which has many improvements over the Beta1 release.