Rash thoughts about .NET, C#, F# and Dynamics NAV. » F#

"Fake – F# Make" 1.40.5.0 released – Bugfixes for CruiseControl.NET

Steffen Forkmann — Wed, 14 Jul 2010 09:15:05 +0000

Today I released “FAKE – F# Make” version 1.40.5.0. This release fixes some issues with CruiseControl.NET compatibility and improves the MSBuild task.

Important links:

Changes for CruiseControl.NET

Daniel Nauck created a FAKE task for CC.Net. This task allows a much easier configuration of FAKE. Please download the latest CC.NET build if you want to use it.

Daniel also created a FAKE build project on his server which showed us some compatibility issues:

In FAKE:
- Race condition in FAKE’s trace functionality
- Better XML tracing if something fails
- The tracing buffer will be flushed after every build target
- Every task has a Timeout property (Default: 5 min.)
- Setting of environment variables fixed
- Showing labels in NUnit is now the default
In Docu:
- Unhandled exception in Docu.exe
In CC.NET:
- Implemented support for git submodules (CCNET-1922)

@Daniel: Thank you very much for helping me on this CruiseControl.NET stuff. I really appreciate this.

MSBuild task changes

The MSBuild task in FAKE gets a sequence of project files and compiles them in the given order. This might be slow if you have lots of dependent projects. Then MSBuild might analyze the dependencies over and over again. To fix this issue I currently see two possible solutions:

Generate a temporary solution file and use this for compilation.
Analyze the given projects and remove all dependent projects from the list.

FAKE 1.40.5.0 implements the second idea. If you have a better idea please contact me.

“Fake – F# Make” 1.33.0 released

Steffen Forkmann — Sun, 11 Jul 2010 15:11:49 +0000

Yesterday I released “FAKE – F# Make” version 1.33.0. This release has lots of small bug fixes and a couple of new features.

Important links:

Git helpers -Fake.Git.dll

Git is a distributed revision control system with an emphasis on speed. Git was initially designed and developed by Linus Torvalds for Linux kernel development. Every Git working directory is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on network access or a central server.

[Wikipedia]

In the last couple of months I worked on small helper library for controlling Git. This library is now released as part of “FAKE – F# Make”. You can find the source code at http://github.com/forki/FAKE/tree/master/src/app/Fake.Git/.

Features:

Repository handling
- init, clone
Submodules
- init, clone, information about submodules
Branches
- checkout, create, delete, merge, rebase, tag, pull, push, reset, commit, …
SHA1 calculation

Documentation generation with James Gregory’s docu tool

What’s a docu? A documentation generator for .Net that isn’t complicated, awkward, or difficult to use. Given an assembly and the XML that’s generated by Visual Studio, docu can produce an entire website of documentation with a single command.

[docu website]

Fake comes bundled with James Gregory’s documentations generator “docu”, which converts XML-Documentation comments into HTML files. All you need to do is downloading a template and calling the docu task inside your build script:

!+ (buildDir + "*.dll")
     |> Scan
     |> Docu (fun p ->
         {p with
             ToolPath = docuPath + "docu.exe"
             TemplatesPath = templatesSrcDir
             OutputPath = docsDir })

Since FAKE builds its own documentation with docu I started to add more (and hopefully better) XML doc comments. My plan is to describe more and more of the internal FAKE functions in the next releases. An updated HTML-document (generated via a docu task) can be found at http://www.navision-blog.de/fake/.

Side by side specification

For Test-driven development (TDD) it’s sometimes nice to have the specifications next to the implementation files since the specs are considered as documentation.

By using a tool like VSCommands it is possible to group the implementation with the specs (see also http://gist.github.com/457248).

This “side by side specification” makes TDD a lot easier but of course we don’t want to deploy the specification classes and the test data.

==>

FAKE has a new feature which automatically removes all specification files and test framework references according to a given convention:

Target "BuildApp" (fun _ –>
      !+ @"src\app\**\*.csproj"
         |> Scan
         |> Seq.map (
             RemoveTestsFromProject
                 AllNUnitReferences      // a default references convention
                 AllSpecAndTestDataFiles // a default file convention
                 )
         |> MSBuildRelease buildDir "Build"
         |> Log "AppBuild-Output: "
)

The conventions are simple functions and can be customized e.g.:

/// All Spec.cs or Spec.fs files and all files containing TestData
let AllSpecAndTestDataFiles elementName (s:string) =
     s.EndsWith "Specs.cs" ||
       s.EndsWith "Specs.fs" ||
       (elementName = "Content" && s.Contains "TestData")

Miscellaneous

SQL Server helpers are moved to Fake.SQL.dll
- Additional functions for attaching and detaching databases.
FileHelper.CopyCached function was added
- Copies the files from a cache folder. If the files are not cached or the original files have a different write time the cache will be refreshed.
EnvironmentHelper.environVarOrDefault added
- Retrieves the environment variable or a given default.
Fixed Issue 3: toRelativePath calculates paths with ..\..\ if needed
Added a build time report to the build output.
XPathReplace and XMLPoke tasks added.
- Replaces text in an XML file at the location specified by an XPath expression.
ILMerge task added
Windows Installer XML (WiX) task added

“FAKE – F# Make” 1.20.0 released

Steffen Forkmann — Wed, 12 May 2010 12:26:43 +0000

Today I released a new bugfix release for “FAKE – F# Make”. We fixed some path and logging issues and as a new feature we introduced the @@ operator which allows to combine paths.

Using a MailboxProcessor to speedup “FAKE – F# MAKE”

Steffen Forkmann — Fri, 07 May 2010 11:37:28 +0000

Earlier today I released “FAKE – F# Make” version 1.10.0. This new release contains a lot path issue fixes for Mono and a new architecture for logging and tracing.

A guy named Joel Mueller had an awesome idea and sent me some patches. He noticed that TraceHelper.fs writes all messages synchronously to the console and/or a XML output file, which means the actual build operations must wait on the writing of hundreds of trace messages, slowing down the actual build.

His idea was to use a MailboxProcessor to buffer up the trace messages and write them out asynchronously, so that the actual build can proceed at full speed.

type Message = 
    { Text      : string
      Color     : ConsoleColor
      Newline   : bool
      Important : bool}
 
/// ….
 
let buffer = MailboxProcessor.Start (fun inbox ->
    let rec loop () = 
        async {
            let! (msg:Message) = inbox.Receive()
            match traceMode with
            | Console -> logMessageToConsole msg
            | Xml     -> appendXML msg.Text
 
            return! loop ()}
 
    loop ())      

Now all internal logging and tracing functions can post their their messages to the inbox of the MailboxProcessor:

/// Logs the specified string (via message buffer)
let logMessage important newLine message =
    match traceMode with
    | Console ->
        { Text = message; 
          Important = important; 
          Newline = newLine; 
          Color = ConsoleColor.White }
          |> buffer.Post
    | Xml     -> 
        { defaultMessage with 
            Text = sprintf "" 
                     message }
          |> buffer.Post 

This idea reduces the build time of FAKE’s self build from 3 min. to 2 min. Which is really amazing, since I didn’t have to change anything in the build script. This version is compatible to the last released version.

Please download “FAKE – F# Make” version 1.10.0 and tell me what you think.

Solving KataYahtzee with F# and NaturalSpec

Steffen Forkmann — Sat, 24 Apr 2010 19:04:36 +0000

Today I’m starting a new blog post series about solving code katas in F# and with the help of my NaturalSpec project. A code kata is a programming exercise which helps to improve your skills through practice and repetition. In this series we want to use the Test Driven Development TDD approach which means in the context of NaturalSpec that we have to write our specs before we implement the algorithm.

Problem Description

“The game of yahtzee is a simple dice game. Each round, each player rolls five six sided dice. The player may choose to reroll some or all of the dice up to three times (including the original roll). The player then places the roll at a category, such as ones, twos, sixes, pair, two pairs etc. If the roll is compatible with the score, the player gets a score for this roll according to the rules. If the roll is not compatible, the player gets a score of zero for this roll.

The kata consists of creating the rules to score a roll in any of a predefined category. Given a roll and a category, the final solution should output the score for this roll placed in this category.”

[codingdojo.org]

Category 1 – Ones, Twos, Threes, Fours, Fives, Sixes

“Ones, Twos, Threes, Fours, Fives, Sixes: The player scores the sum of the dice that reads one, two, three, four, five or six, respectively. For example, 1, 1, 2, 4, 4 placed on "fours" gives 8 points.”

After reading this category description we could come up with the following spec:

module Yahtzee.Specs
 
open NaturalSpec
 
let placed_on category list =
    printMethod category
    calcValue category list
 
[]     
let “Given 1,1,2,4,4 placed on "fours" gives 8 points.“ () =   
    Given (1, 1, 2, 4, 4)
      |> When (placed_on Fours)
      |> It should equal 8
      |> Verify

Since we really want to implement six different categories we should also add some more scenarios like this one:

[]     
let “Given 1,1,6,4,6 placed on "sixes" gives 12 points.“ ()=   
    Given (1, 1, 6, 4, 6)
      |> When (placed_on Sixes)
      |> It should equal 12
      |> Verify
 
// …

Now we have some specs but they will all fail since we don’t have anything implemented yet. So we have to come up with a model of dice rolls and categories. As the specs suggests we model the dice roll as a tuple of ints and the category as a discriminated union:

module Yahtzee.Model
 
type Roll = int * int * int * int * int
 
type Category =
| Ones
| Twos
| Threes
| Fours
| Fives
| Sixes   

The tuple is a natural choice for the dice roll, but for easier calculation we add a helper function which converts it into a list. This allows use to use the standard list functions and therefore summing the values becomes trivial:

let toList (roll:Roll) =
    let a,b,c,d,e = roll
    [a;b;c;d;e]
 
let sumNumber number =
    Seq.filter ((=) number)
      >> Seq.sum
 
let calcValue category roll =
    let list = toList roll
    match category with
    | Ones   -> sumNumber 1 list
    | Twos   -> sumNumber 2 list
    | Threes -> sumNumber 3 list
    | Fours  -> sumNumber 4 list
    | Fives  -> sumNumber 5 list
    | Sixes  -> sumNumber 6 list

Now we can run our scenarios with any NUnit runner. I’m using the default NUnit GUI runner here, which gives me a picture like this:

Category 2 – Pair

“Pair: The player scores the sum of the two highest matching dice. For example, 3, 3, 3, 4, 4 placed on "pair" gives 8.”

The kata description gives us some new scenarios. As seen above we should specify them before writing the code.

[]     
let “Given 3,3,3,4,4 placed on "pair" gives 8.“ () =   
    Given (3, 3, 3, 4, 4)
      |> When (placed_on Pair)
      |> It should equal 8
      |> Verify
 
[]     
let “Given 5,3,5,4,4 placed on "pair" gives 10.“ () =   
    Given (5, 3, 5, 4, 4)
      |> When (placed_on Pair)
      |> It should equal 10
      |> Verify    
 
[]     
let “Given 1,2,3,4,5 placed on "pair" gives 0.“ () =   
    Given (1, 2, 3, 4, 5)
      |> When (placed_on Pair)
      |> It should equal 0
      |> Verify      

Since we use a new category we now have to extend our model and the calcValue function:

type Category =
| Ones
  // …
| Sixes
| Pair
 
// …
let sumAsPair list number =
    let numberCount = 
        list 
          |> Seq.filter ((=) number) 
          |> Seq.length
 
    if numberCount >= 2 then 2 * number else 0
 
let calcValue category roll =
    let list = toList roll
    match category with
    | Ones   -> sumNumber 1 list
        // …
    | Sixes  -> sumNumber 6 list
    | Pair   -> 
        [1..6]
          |> Seq.map (sumAsPair list)
          |> Seq.max   

Category 3 – Two pairs

“Two pairs: If there are two pairs of dice with the same number, the player scores the sum of these dice. If not, the player scores 0. For example, 1, 1, 2, 3, 3 placed on "two pairs" gives 8.”

[]     
let “Given 1,1,2,3,3 placed on "two pair" gives 8.“ () =   
    Given (1, 1, 2, 3, 3)
      |> When (placed_on TwoPair)
      |> It should equal 8
      |> Verify
 
[]     
let “Given 1,6,6,3,3 placed on "two pair" gives 18.“ () =   
    Given (1, 6, 6, 3, 3)
      |> When (placed_on TwoPair)
      |> It should equal 18
      |> Verify
 
[]     
let “Given 1,1,2,4,3 placed on "two pair" gives 0.“ () =   
    Given (1, 1, 2, 4, 3)
      |> When (placed_on TwoPair)
      |> It should equal 0
      |> Verify  

Implementing this category is a little bit tricky but with the help of our Pair function and some more standard sequence combinators we can get our spec green:

type Category =
| Ones
  // …
| TwoPair
 
let allPairs =
    [for i in 1..6 do
       for j in 1..6 -> i,j]
 
let calcValue category roll =
    // …
    | TwoPair   -> 
        allPairs
          |> Seq.filter (fun (a,b) -> a <> b)
          |> Seq.map (fun (a,b) -> 
                let a’ = sumAsPair list a
                let b’ = sumAsPair list b
                if a’ = 0 || b’ = 0 then 0 else a’ + b’)
          |> Seq.max     

Category 4 – Three of a kind

“Three of a kind: If there are three dice with the same number, the player scores the sum of these dice. Otherwise, the player scores 0. For example, 3, 3, 3, 4, 5 places on "three of a kind" gives 9.”

[]     
let “Given 3,3,3,4,5 placed on "three of a kind" gives 9“()=   
    Given (3, 3, 3, 4, 5)
      |> When (placed_on ThreeOfAKind)
      |> It should equal 9
      |> Verify
 
[]     
let “Given 3,4,3,4,5 placed on "three of a kind" gives 0“()=   
    Given (3, 4, 3, 4, 5)
      |> When (placed_on ThreeOfAKind)
      |> It should equal 0
      |> Verify 

Now it is time to refactor our code. The sumAsPair function should be extended to a sumAsTuple function:

type Category =
| Ones
  // …
| ThreeOfAKind
 
let sumAsTuple value list number =
    let numberCount = 
        list 
          |> Seq.filter ((=) number) 
          |> Seq.length
 
let takeBestTuple value list =
    [1..6]
        |> Seq.map (sumAsTuple value list)
        |> Seq.max  
    if numberCount >= value then value * number else 0
 
let calcValue category roll =
      // …
    | Pair   -> takeBestTuple 2 list
    | TwoPair   -> 
        allPairs
          |> Seq.filter (fun (a,b) -> a <> b)
          |> Seq.map (fun (a,b) -> 
                let a’ = sumAsTuple 2 list a
                let b’ = sumAsTuple 2 list b
                if a’ = 0 || b’ = 0 then 0 else a’ + b’)
          |> Seq.max
    | ThreeOfAKind –> takeBestTuple 3 list

Category 5 – Four of a kind

“Four of a kind: If there are four dice with the same number, the player scores the sum of these dice. Otherwise, the player scores 0. For example, 2, 2, 2, 2, 5 places on "four of a kind" gives 8.”

[]     
let “Given 2,2,2,2,5 placed on "four of a kind" gives 8“ ()=   
    Given (2, 2, 2, 2, 5)
      |> When (placed_on FourOfAKind)
      |> It should equal 8
      |> Verify
 
[]     
let “Given 2,6,2,2,5 placed on "four of a kind" gives 0“ ()=   
    Given (2, 6, 2, 2, 5)
      |> When (placed_on FourOfAKind)
      |> It should equal 0
      |> Verify   

With the help of the takeBestTuple function this becomes trivial:

type Category =

| Ones

// …

| FourOfAKind

let calcValue category roll =

// …

| FourOfAKind -> takeBestTuple 4 list

Category 6 – Small straight

“Small straight: If the dice read 1,2,3,4,5, the player scores 15 (the sum of all the dice), otherwise 0.”

[]     
let “Given 1,2,3,4,5 placed on "Small Straight" gives 15“()=   
    Given (1,2,3,4,5)
      |> When (placed_on SmallStraight)
      |> It should equal 15
      |> Verify
 
[]     
let “Given 1,2,5,4,3 placed on "Small Straight" gives 15“()=   
    Given (1,2,5,4,3)
      |> When (placed_on SmallStraight)
      |> It should equal 15
      |> Verify
 
[]     
let “Given 1,2,6,4,3 placed on "Small Straight" gives 0“()=   
    Given (1,2,6,4,3)
      |> When (placed_on SmallStraight)
      |> It should equal 0
      |> Verify  

As in all the above scenarios we don’t assume any specific order in our rolls but for this category it is easier to test if the data is sorted:

type Category =
| Ones
  // …
| SmallStraight
 
let calcValue category roll =
      // …
    | SmallStraight -> 
        match list |> List.sort with
        | [1;2;3;4;5] -> 15
        | _ -> 0

Category 7 – Large straight

“Large straight: If the dice read 2,3,4,5,6, the player scores 20 (the sum of all the dice), otherwise 0.”

[]     
let “Given 2,3,4,5,6 placed on "Large Straight" gives 20“()=   
    Given (2,3,4,5,6)
      |> When (placed_on LargeStraight)
      |> It should equal 20
      |> Verify
 
[]     
let “Given 6,2,5,4,3 placed on "Large Straight" gives 20“()=   
    Given (6,2,5,4,3)
      |> When (placed_on LargeStraight)
      |> It should equal 20
      |> Verify
 
[]     
let “Given 1,2,6,4,3 placed on "Large Straight" gives 0“()=   
    Given (1,2,6,4,3)
      |> When (placed_on LargeStraight)
      |> It should equal 0
      |> Verify  

Of course the implementation is exactly the same as for the small straight:

type Category =
| Ones
  // …
| LargeStraight
 
let calcValue category roll =
      // …
    | LargeStraight -> 
        match list |> List.sort with
        | [2;3;4;5;6] -> 20
        | _ -> 0

Category 8 – Full house

“Full house: If the dice are two of a kind and three of a kind, the player scores the sum of all the dice. For example, 1,1,2,2,2 placed on "full house" gives 8. 4,4,4,4,4 is not "full house".”

[]     
let “Given 1,1,2,2,2 placed on "full house" gives 8.“ () =   
    Given (1,1,2,2,2)
      |> When (placed_on FullHouse)
      |> It should equal 8
      |> Verify
 
[]     
let “Given 4,4,4,4,4 placed on "full house" gives 0.“ () =   
    Given (4,4,4,4,4)
      |> When (placed_on FullHouse)
      |> It should equal 0
      |> Verify
 
[]     
let “Given 1,1,2,3,2 placed on "full house" gives 0.“ () =   
    Given (1,1,2,3,2)
      |> When (placed_on FullHouse)
      |> It should equal 0
      |> Verify 

Implementing the FullHouse category is easy if we reuse our solutions to the Two pairs category:

type Category =
| Ones
  // …
| FullHouse
 
let takeBestCombo value1 value2 list =
    allPairs
        |> Seq.filter (fun (a,b) -> a <> b)
        |> Seq.map (fun (a,b) -> 
            let a’ = sumAsTuple value1 list a
            let b’ = sumAsTuple value2 list b
            if a’ = 0 || b’ = 0 then 0 else a’ + b’)
        |> Seq.max
 
let calcValue category roll =
      // …
    | TwoPair   -> takeBestCombo 2 2 list
      // …
    | FullHouse   -> takeBestCombo 2 3 list

Category 9 – Yahtzee

“Yahtzee: If all dice are the have the same number, the player scores 50 points, otherwise 0.”

Here we can use NaturalSpec’s ScenarioTemplates in order to specify all Yahtzees:

[]
[]
[]
[]
[]
[]
let “Given n,n,n,n,n placed on "Yahtzee" gives 50.“ n =   
    Given (n,n,n,n,n)
      |> When (placed_on Yahtzee)
      |> It should equal 50
      |> Verify
 
[]     
let “Given 1,1,1,2,1 placed on "Yahtzee" gives 50.“ () =   
    Given (1,1,1,2,1)
      |> When (placed_on Yahtzee)
      |> It should equal 0
      |> Verify

The implementation is pretty easy:

type Category =
| Ones
  // …
| Yahtzee
 
let calcValue category roll =
      // …
    | Yahtzee -> 
        let a,b,c,d,e = roll
        if a = b && a = c && a = d && a = e then 50 else 0 

Category 10 – Chance

“Chance: The player gets the sum of all dice, no matter what they read.”

[]     
let “Given 1,1,1,2,1 placed on "Chance" gives 6.“ () =   
    Given (1,1,1,2,1)
      |> When (placed_on Chance)
      |> It should equal 6
      |> Verify
 
[]     
let “Given 1,6,1,2,1 placed on "Chance" gives 11.“ () =   
    Given (1,6,1,2,1)
      |> When (placed_on Chance)
      |> It should equal 11
      |> Verify

This seems to be the easiest category as we only have to sum the values:

type Category =
| Ones
  // …
| Chance
 
let calcValue category roll =
      // …
    | Chance -> List.sum list

Conclusion

We used a lot of F#’s sequence combinators, pattern matching and discriminated unions in this kata. I think this shows that F# is very well suited for such a problem and with NaturalSpec we can easily use a TDD/BDD approach.

The complete source code can be found in the NaturalSpec repository.

If you want to know more about a specific part of the kata or NaturalSpec feel free to contact me.

“FAKE – F# Make” and NaturalSpec released

Steffen Forkmann — Tue, 13 Apr 2010 08:06:46 +0000

Yesterday Microsoft released the RTM versions of Visual Studio 2010, .NET Framework 4.0 and F# 2.0.0.0 and so it is time to announce the first official releases of “Fake – F# Make” and NaturalSpec. Both projects are now compatible with Visual Studio 2010 RC and RTM and the corresponding F# versions.

Fake – F# Make version 1.0.0

"FAKE – F# Make" is a build automation system, which is intended to provide a much better tooling support than XML-based build languages like MSBuild or NAnt. Due to its integration in F#, all benefits of the .NET Framework and functional programming can be used, including the extensive class library, powerful debuggers and integrated development environments like Visual Studio 2008, Visual Studio 2010 or SharpDevelop, which provide syntax highlighting and code completion.

Like F# itself the new build language was designed to be succinct, typed, declarative, extensible and easy to use.

Project page with samples and articles
Download page
Github repository

NaturalSpec version 1.0.0

NaturalSpec is a UnitTest framework based on NUnit and completely written in F# – but you don’t have to learn F# to use it. The idea is that you can write your spec mostly in a natural language like in the following sample:

[]
let “When removing an element from a list it should not contain the element“() =
  Given [1;2;3;4;5]                 // "Arrange" test context
    |> When removing 3              // "Act"
    |> It shouldn’t contain 3       // "Assert"
    |> It should contain 4          // another assertion
    |> It should have (Length 4)    // Assertion for length
    |> It shouldn’t have Duplicates // it contains duplicates ?
    |> Verify                       // Verify scenario

Project page with samples and articles
Download page
Github repository

If you have any questions about the projects feel free to contact me.

F# Vortrag in Hamburg-Altona

Steffen Forkmann — Mon, 15 Mar 2010 09:25:30 +0000

Am Mittwoch, den 17.03.2010 werde ich in Hamburg-Altona einen Vortrag zu “Funktionaler Programmierung mit F#” halten.

“Funktionale Programmiersprachen nehmen seit geraumer Zeit einen hohen Stellenwert in der Wissenschaft ein. Demnächst könnte es eine dieser Sprachen sogar aus dem Forschungsbereich direkt in den Mainstream schaffen. Visual Studio 2010 wird neben C# und VB.NET die funktionale Programmiersprache F# als dritte Hauptsprache anbieten. Der Vortrag soll einen Einblick in funktionale Konzepte und deren Umsetzung in F# geben. Insbesondere soll auf “Funktionen höherer Ordnung”, Typinferenz, Currying, Pattern Matching, “Unveränderlichkeit” und parallele Programmierung eingegangen werden.”

Mittwoch, 17.03.2010 um 19:00 Uhr
Kinderkrankenhaus Altona
Bleickenallee 38
22763 Hamburg
Treffpunkt: Haupteingang Empfang

“FAKE – F# Make” 0.29 released – Ready for F# February 2010 CTP and .NET 4.0 RC

Steffen Forkmann — Sun, 14 Feb 2010 16:56:07 +0000

Last week I released version 0.29 of my build automation tool “FAKE – F# Make”. The new version comes along with a couple of changes which I will now describe.

F# February 2010 CTP and .NET 4.0 RC

“FAKE – F# Make” should be completely compatible with both, the F# February 2010 CTP and the F# version which is included in Visual Studio 2010 RC.

FAKE self build and binaries on teamcity.codebetter.com

Since “FAKE – F# Make” is a build automation tool, it was always used for it’s own build process. Now this build process could be moved to an open CI server at teamcity.codebetter.com. If you login as a guest you can download the latest “FAKE – F# Make” binaries from there.

FAKE on build servers without F#

With the new F# CTP there is no longer a need for installing F# on the build agents. In fact FAKE itself was built on build agents which don’t have a F# installation.

If you want to create such build scripts you have to do the following:

Download the standalone zip file of the F# CTP
Put the bin subfolder into your project tree
Modify the FSIPath value in the FAKE.exe.config file to match your FSharp bin folder
1. If you copy the contents the F# bin folder into ./tools/FSharp/ it should just work.

If you have F# projects you also need to modify your .fsproj files like this:

….
..\..\..\tools\FSharp\

…

This modifications should take care that MSBuild will use the F# compiler from your tools paths.

Generate your documentations with “docu”

“What’s a docu? A documentation generator for .Net that isn’t complicated, awkward, or difficult to use. Given an assembly and the XML that’s generated by Visual Studio, docu can produce an entire website of documentation with a single command.” [docu Homepage]

“FAKE – F# Make” 0.29 is bundled with this new documentation tool which can easily convert your xml-Documentation into some nice html pages. You can use the tool with the new Docu task like this:

Target? GenerateDocumentation <-
    fun _ ->
        Docu (fun p ->
            {p with
               ToolPath = @".\tools\FAKE\docu.exe"
               TemplatesPath = @".\tools\FAKE\templates"
               OutputPath = docDir })
            (buildDir + "MyAssembly.dll")

You will also need the docu templates, which you can download from the product homepage. I’m planning to bundle some basic templates with the next version of FAKE.

What’s next?

At the moment I’m working on ILMerge task for FAKE. I hope to release this with the next version. There are also some open issues with the Mono support but since teamcity.codebetter.com is getting a mono build agent I hope to make some progress here too.

If you have any questions or ideas for new features please contact me.

New syntactic sugar for “FAKE – F# Make” – Getting rid of magic strings

Steffen Forkmann — Mon, 08 Feb 2010 17:58:12 +0000

The new version 0.27 of “FAKE – F# Make” comes with new syntactic sugar for build targets and build dependencies. Don’t be afraid the old version is still supported – all scripts should still work with the new version.

The problem

Consider the following target definition:

let buildDir = "./build/"
 
Target "Clean" (fun _ ->
  CleanDir buildDir
)
 
Target "Default" (fun _ ->
  trace "Hello World from FAKE"
)
 
"Default" <== ["Clean"]
 
run "Default"

As you can see we are having a lot of “magic strings” for the target names and the dependency definitions. This was always a small shortcoming in FAKE, since this doesn’t allow refactoring and may result in runtime errors.

One of my goals for “FAKE – F# Make” is to remove these strings in future versions. Unfortunately this is not that easy, because it causes a lot of internal issues. In particular logging to the build server is much harder if you don’t have a target name.

The first step

As posted in a bitbucket comment by cipher we could use the “dynamic lookup operator” to remove some of the magic strings without breaking any internal code.

As a result we can rewrite the above sample as:

let buildDir = "./build/"
 
Target? Clean <-
    fun _ -> CleanDir buildDir
 
Target? Default <-
    fun _ -> trace "Hello World from FAKE"
 
For? Default <- Dependency? Clean
 
Run? Default

All magic strings suddenly disappeared. I think this syntax looks really nice, but unfortunately the strings are not really gone, since the token Default is only checked at runtime.

The idea for future versions

Since the new syntax is really just syntactic sugar I’m always interested in a better solution. Currently I’m working on a syntax using monads. The result could look like this:

let buildDir = "./build/"
 
let Clean = target { CleanDir buildDir }
let Default = 
  target { 
    trace "Hello World from FAKE" 
    trace "Another line"
  }
 
Default <== [Clean]

Run Default

This way the magic string are really gone, but my current problem is retrieving the target name from the let-binding name. Please leave a comment if you have an idea to solve this issue.

Terminverschiebung des F#-Vortrages in Bad Homburg

Steffen Forkmann — Mon, 11 Jan 2010 14:04:47 +0000

Der Termin für meinen F#-Talk bei der .NET Usergroup Frankfurt hat sich auf nächste Woche Donnerstag (21.01.2010) 18:30 verschoben.

Veranstaltungsort ist die Geschäftsstelle von Microsoft in Bad Homburg, Siemensstrasse (Anfahrtsbeschreibung).

Bitte beachten Sie, dass für den Besuch dieses User Group Meetings eine Anmeldung auf der Web Seite der .NET User Group zwingend notwendig ist.

Abstract:

Funktionale Programmiersprachen nehmen seit geraumer Zeit einen hohen Stellenwert in der Wissenschaft ein. Demnächst könnte es eine dieser Sprachen sogar aus dem Forschungsbereich direkt in den Mainstream schaffen. Visual Studio 2010 wird neben C# und VB.NET die funktionale Programmiersprache F# als dritte Hauptsprache anbieten. Der Vortrag soll einen Einblick in funktionale Konzepte und deren Umsetzung in F# geben. Insbesondere soll auf “Funktionen höherer Ordnung”, Typinferenz, Currying, Pattern Matching, “Unveränderlichkeit” und parallele Programmierung eingegangen werden.