F# Released!

[ Note: An update to this release has been announced: see version at http://blogs.msdn.com/dsyme/archive/2007/05/06/f-1-9-1-9-available-currently-msi-only-includes-overloaded-numeric-conversion-functions-and-checked-arithmetic.aspx ]

I am very pleased to announce that F# 1.9.1 is now available for download. This is a major release for us, a first step toward F# 2.0, and incorporating two exiciting new features: Active Patterns and Implicit Class Construction.

The release is not yet the default download on research.microsoft.com/fsharp, but you can get it at: http://research.microsoft.com/research/downloads/details/c8d270ce-dc93-4b82-8125-2c57036520b3/details.aspx http://research.microsoft.com/research/downloads/details/b46c7032-149c-4da3-a027-7768210a158d/details.aspx

[ Note: we’ve had one report of an installation issue on Windows XP, and one on Windows Vista. If you have a problem try installing the VC runtime libraries http://www.microsoft.com/downloads/details.aspx?FamilyID=32BC1BEE-A3F9-4C13-9C99-220B62A191EE&displaylang=en
Please let us know if you have problems, by emailing us at “fsbugs at microsoft dot com”. ]

I’ve posted the full release notes in another blog entry, and a draft paper on active patterns is now also available. The highlights in this release are:

  • Active Patterns.  Active patterns give a form of extensible pattern matching on abstract values. F# active patterns allow you to pattern match against .NET object values such as XML, System.Type values and LINQ Expression trees. In this redesigned version they become an official part of the language and some novel additions give a lightweight and non-intrusive mechanism to both partial patterns, parameterized patterns and “complete” decompositions (views) of types.

  • Implicit Class Construction.  This lovely feature makes writing classes considerably more succinct and helps to further bridge the gap between type-inferred functional programming and object-oriented programming.

  • Simpler Quotation Library.  The F# Quotation library has been redesigned to use active patterns and to have a much simpler model of types, and as such is now much more powerful.  F# Quotations are used to interoperate with LINQ, Accelerator and other meta-programming components.

  • Methods as first-class values.  You can now use .NET methods as functions in many situations, e.g. “map File.ReadAllLines [“a.txt”; “b.txt”]”

  • Attributes for C Interoperability.  StructLayout, FieldLayout etc. now supported

  • Better IntelliSense.  IntelliSense on more expressions, more information in ToolTips.

  • Syntactic improvements, Bug fixes, Library additions and much more.  A whole bunch of things here – more detail in the release notes

  • Since I preannounced the release we’ve been stabilizing it with our internal users – many thanks to all those who tried out earlier versions of the release and submitted bug reports.

    Happy coding!


    Comments (13)

    1. That’s awesome news Don. Kudos to yourself and the rest of the F# team 🙂

    2. Gilles Ratel says:


       Thank you for this release in Easter time.

       A just in time for me.

       I download and look.

       Happy Easter for you.

      ratel_gilles0videotron_ca (replace _ and 0 …)

    3. I’m glad to announce the availability of a draft paper on F# Active Patterns, co-authored by James Margetson

    4. falcon says:


      Thanks for the release.  I’ll be going over the Active Patterns paper over the next few days.  In the mean time, I hope you do a substantial demo of using F# with WPF for data visualization.  3D looks very snazzy, but rarely makes sense in a business setting.  For example, I’d like to link up a stock feed to WPF through F#. It is overkill to use some 3rd party charting component, just show us how to link the output of a list-comprehension to an x/y-axis display.  I think WPF and F# are a fantastic combination.

    5. Justin y yo estamos empezando a jugar con F# (version 1.9.1 esta disponible ) open System; Console.WriteLine("hello

    6. On Don Syme’s WebLog on F# and Other Research Projects , there are several interesting recent entries

    7. Hi all, I’m glad to announce the availability of F# It’s available for download from this link:

    8. F# has been released by the F# team. To quote: This is in general a bug fix release over,…

    9. Don Syme’s WebLog on F# and Other Research Projects : F# available (currently MSI only): Includes

    10. Aswath says:

      Thanks for your post . i am unable to download new version i.e(F# ). any body help me out

    11. Effexor. says:

      Effexor. Side effects of effexor xr. Effexor withdrawl.