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

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:

1. Download the standalone zip file of the F# CTP
2. Put the bin subfolder into your project tree
3. 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:

<PropertyGroup>
   ….
  <FscToolPath>..\..\..\tools\FSharp\</FscToolPath>
</PropertyGroup>
…
<Import Project="..\..\..\tools\FSharp\Microsoft.FSharp.Targets" />

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:

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.

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:

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:

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:

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.