F# and using strings for method and class/type names

So after about 2 months of jumping back and forth between languages (Including and not only: Ruby, Python, IronPython, Boo, Scala, and a lot more I don’t remember) I’ve finally settled on F# for more reasons than I will put in this post. BUT one thing that kind of blew me away, and I realize that doesn’t take much (I thought the ending to Terminator 3 was great), was the ability to name methods with string representations… eh wha?

Well I was writing unit tests and stumbled onto the FSUnit “library” (and by “library” I mean a single file). Well on the page there was an example that looked a sumthin’ like this:

type ``Given a LightBulb that has had its state set to true`` ()=  

Now if you haven’t used F# just replace “type” with “class”. Essential there is a string/text built name. Not something you see, or at least I haven’t, in any old language. So I went forth and was fruitful and multipled… with unit tests… gross.

type public ``When Adding``() =
    let returnThing = new MethodResult() :> IResult
    let randomTool = new RandomTool()

    member public x.``A Warning Message The Success Flag Is Set To True``() =
        returnThing.AddMessage(new MessageItem(randomTool.RandomString(10), MessageCategory.Warning)).Success |> should be True

And using Resharper’s unit test box thingy it gave a read out of:

  When Adding A Warning Message  
     The Success Flag Is Set To True             Success

Now I’m not sure how useful this is for non unit testing but I think it’s obvious it is to reading Unit Test results. Pretty nice.

XUnit and Connection Strings

A real quick one but maybe a good one.

I was running the xUnit.gui.exe program to run units tests using xUnit… duh. Problem I ran into is that xUnit is not a part of the solution that the tests were. This caused issues when trying to run integration tests since the needed app.config wouldn’t be read by xUnit as the config file used when running an app is the config file from the topmost (Usually UI) project/application. So I made a wild guess that if I follow that logic, what little there may be, and add the connection strings to the xunit.gui.exe.config file as if it were an app.config/web.config, it should use the connection strings added… and turns out it did.

And there you have it… it being the solution and not a clown.

Fun with F# and Method Reduction

So the first and second methods came from this book , but I thought for fun I might reduce it further to see
how small a call could get.

Basically take a number and divide it by another number 3 times.

let bytesToGb item =
let itemB = item / 1024I
let itemC = itemB / 1024I
let itemD = itemC / 1024I

Is the same as:
let bytesToGb item =
let x = x / 1024I
let x = x / 1024I
let x = x / 1024I

And more reduction:
let bytesToGb item =
|> (fun x -> x/1024L)
|> (fun x -> x/1024L)
|> (fun x -> x/1024L)

Or more:
let divide x = x/1024L
let bytesToGb = divide >> divide >> divide

If you’re familiar with Func/Action, Linq, ect this might actually look a lot like some of the newer “functional like” additions to C#. Well at least the third one. Funny part, and I didn’t know this, is that most of the more interesting additions to C# (Generics, Linq, Lambda expressions) actually came from F#; Which was built to match other existing functional languages like Haskel)  Go figure.

XUnit.gui.exe – this assembly is built by a runtime newer than the currently…

So ran into this while using XUnit (For my new F# adventure) and I ran into this error when I tried to use the XUnit.gui.exe thing:

“This assembly is built by a runtime newer that the currently loaded runtime and cannot be loaded.”

Pretty straightforward in that I am creating projects in 4.0 and one can infer XUnit wasn’t ready for this. At first I was thinking, painful as that is, that XUnit can’t handle 4.0. To my relief, I found this post at:


Great… except it only talks about the xunit.console.exe.config and there wasn’t a xunit.gui.exe.config. Well in a moment of questionable brilliance, more like a slight moment of clarity, I decided to copy the xunit.console.exe.config and rename the copied file to “xunit.gui.exe.config” and it worked. Go figure.

This is a picture for the slighty less lazy:

And for those more lazy than that:

Here’s the xml in case you’re more lazy than I am.

Into the unknown… sort of.

So after about eh 3? months of not writing anything (Mostly due to the joy slash nightmare of a newborn) I’ve had a real “come to [Religious Figure]” moment… And that moment has taught me that java based off shoot languages are a pain in the ass to even get started with. This is the typical how to guide:

So yeah, I’m back to the Net but with a twist. Not much an M. Night ‘They call me Mr. Glass’ kind of twist, more of the ‘Oh for &$#@’s sake’ The Happening kind of twist. Yes, I am venturing into F#… and maybe never back again… except for work. But never to be back again outside of work. Ah who am I kidding? Who cares. (That includes me)