fsharpener

Setting up Visual Studio 2008... What to do when all the Templates are gone.

2008-12-09T07:56:00.000-08:00

I bought a Visual Studio license. I was previously running Visual Studio integrated shell . When I installed it, all of the templates were missing.

This was fixed by opening a command prompt, changing to the ide directory where devenv.exe is located and running the command "devenv /installvstemplates"

(make sure VS is shutdown first).

"F-dull": F# beginner's mistake... put a space between '-' and a number

2008-12-03T08:03:00.001-08:00

I made a very simple mistake while trying to follow the PDC 2008 Intro to F# lecture. "JaredPar" straightened me out about two minutes after I submitted it to http://stackoverflow.com . Here is the problem and solution:

PROBLEM:

I was trying to code along with the PDC2008 Into to F# video. I get an error in the last line of the code snippet shown below (that the presenter did not get) "Error 1 This value is not a function and cannot be applied". I am running Fsharp-1.9.6.2 on Visual Studio 2008 shell. The startprice symbol in the last line isunderlined red with same error on mouse over.

type StockAnalyzer (lprices, days) =
    let prices =
        lprices
        |> Seq.map snd
        |> Seq.take days
    static member GetAnalyzers (tickers,days) =
        tickers
        |> Seq.map loadPrices
        |> Seq.map (fun prices -> new  StockAnalyzer (prices, days))
    member s.Return =
        let  lastPrice = prices |> Seq.nth 0
        let  startPrice = prices |> Seq.nth (days - 1)
        lastPrice / startPrice  -1.

SOLUTION:

Try putting a space between the "-" and "1". The F# compiler is interpretting -1 as literally a negative value of 1 instead of subtract 1.

Thanks Jaredpar!

The original stackoverflow post is here.

Microsoft Solver Foundation -Express

2008-12-01T08:12:00.000-08:00

Microsoft jsut released an express edition of their optimization framework called "Solver Foundation". The framework can be used with F#.

http://code.msdn.microsoft.com/solverfoundation/

The best overview of F# that I've seen ...

2008-11-25T07:41:00.000-08:00

Luca Bolognese presented an amazing overview of F# at Microsoft's PDC 2008 conference. You can watch the video here .

The Title of the session is "TL11 An Introduction to F#".

I am watching it a second time right now...