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24hrs in F#

October 14, 2014 10:55 by phil

The easiest place to see what’s going on in the F# community is to follow the #fsharp hash tag on Twitter. The last 24hrs have been as busy as ever, to the point where it can be hard to keep up these days.

Here’s some of the highlights

Events

Build Stuff conference to feature 8 F# speakers:


and workshops including:

FP Days programme is now live, and features key notes from Don Syme & Christophe Grand, and presentations from:


New Madrid F# meetup group announced:


F# MVP Rodrigo Vidal announces DNA Rio de Janeiro:


Try out the new features in FunScript at MF#K Copenhagen:


Mathias Brandewinder will be presenting some of his work on F# & Azure in the Bay Area


Let’s get hands on session in Portland announced:


Riccardo Terrell will be presenting Why FP? in Washington DC


Sessions featuring FsCheck, Paket & SpecFlow scheduled in Vinnitsa (Ukraine)


Projects

Get Doctor Who stats with F# Data HTML Type Provider:


Major update to FSharp.Data.SqlClient:


ProjectScaffold now uses Paket:


Microsoft Research presentation on new DBpedia Type Provider:


Blogs

More F#, Xamarin.Forms and MVVM by Brad Pillow


Cross-platform MSBuild API by Robin Neatherway


Hacking the Dream Cheeky Thunder Missle Launcher by Jamie Dixon:



Want more?

Check out Sergey Tihon’s F# Weekly!


Tags:
Categories: F# | .Net | Mono
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Unboxing FP

October 7, 2014 23:39 by phil

How hard is it to get started in functional programming?

Let’s have a look at how quickly you can get started on a selection of simple expression-oriented programming languages.

Today let’s try Clojure, Elm, F#, Haskell and OCaml.

Online REPL

No install required just point your browser at a URL and you’re off:

Language Online REPL
Clojure http://tryclj.com/
F# http://www.tryfsharp.org/
Elm http://elm-lang.org/try
Haskell http://tryhaskell.org/
OCaml http://try.ocamlpro.com/

 

Each language has an easy to use online REPL with simple lessons to get you through the basics. Elm’s online offering lets you edit multi-line programs, as does Try F#, which also includes intellisense in the online editor.

Development environment

Now you’ve covered the basics you probably want to install a lightweight development environment and start building larger programs:

Clojure

I found LightTable very quick to install and setup. The editor comes with psychedelic colours to help you track opening and closing parenthesis:

FizzBuzz Clojure


I’ve been using Stuart Holloway’s Programming Clojure book as a guide.

Elm

Elm has a very usable online editor, a simple installable REPL, and a wonderful playground feature with Elm Reactor:


F#

If you’re on Windows and have Visual Studio installed then you’ve already got F#. From the file menu click New and select a new F# project or script file.

No Visual Studio, no problem, for Windows the Tsunami IDE is a fast 25MB download, which gives you the latest compiler and an editor with intellisense:

Tsunami IDE

On Mac I’d recommend Xamarin Studio and for Linux MonoDevelop or Emacs.

Functional Programming using F# and Dave Fancher’s recent Book of F# are both great introductory texts.

Haskell

The Haskell platform gives you a compiler and REPL from a simple 100MB install. A combination of a text editor along with the REPL gets you going in no time:

Haskell FizzBuzz

As a guide I’ve been using the Real World Haskell book. Learn you an Erlang some Haskell for great good! looks like a fun read too.

OCaml

Like Haskell, OCaml is bundled in a simple installer and includes the compiler and REPL. Choose your own editor and use the REPL to explore your programs.

I recently picked up OCaml from the Very Beginning and More OCaml, which are both nice concise introductions.

OCaml From The Very BeginningMore OCaml

Conclusions

Using an online REPL you can get started with any of these languages in seconds, and there are plenty of lightweight install options too. Combine that with a good selection of learning resources from books to online courses, and we can conclude that nowadays it’s really not that hard to get started with FP.


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Categories: Clojure | Elm | F# | Haskell | OCaml
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C# 6 Cuts

October 2, 2014 00:21 by phil

In a recent thread on CodePlex Mads Torgeson, C# Language PM at Microsoft, announced 2 of the key features planned for C# 6 release have now been cut:

  • Primary constructors
  • Declaration expressions

According to Mads:

They are both characterized by having large amounts of downstream work still remaining.

primary constructors could grow up to become a full-blown record feature

Reading between the lines Mads seems to be saying the features weren’t finished and even if they were they seemed to conflict with a potential record feature currently being prototyped.

The full thread is here: Changes to the language feature set

Language Design

I think there’s two distinct options when adding new features to an existing language with a large user base:

  • upfront design
  • implement incrementally

Upfront design should mean that all cases are met but comes at a time-to-market cost, where as an incremental implementation means quick releases with the potential risk of either sub-optimal syntax or backward compatibility issues when applying more features.

It appeared at the high level that the C# team’s had initially opted for the incremental option. The feature cuts however suggest to me that there may have been a change in direction towards more upfront design.

Primary Constructors

The primary constructors feature was intended to reduce the verbosity of C#’s class declaration syntax. The new feature appeared to be inspired by F# ’s class syntax.

If you like the idea of a lighter syntax for class declarations then you may just want to try F# which already has a well thought out mature implementation, i.e.

type Person(name:string, age:int) =
    member this.Name = name
    member this.Age = age

Or for simple types use the even simpler record type:

type Person = { Name:string, Age:int }

Note: on top of lighter class syntax F# also packs a whole raft of cool features not available in C#, including powerful pattern matching and data access via Type Providers.

Declaration Expressions

Declaration expressions was again designed to reduce verbosity in C# providing a lighter syntax for handling out parameters. Out parameters are used in C# to allow a method to return multiple values:

int result;
bool success = Int32.TryParse("123", out result);

Again handling multiple return values is handled elegantly in F# which employs first-class tuples, i.e.

let success, value = Int32.TryParse("123")

As shown above, C# out parameters can be simply captured in F# as if the method were returning multiple values as a tuple.

Conclusion

The first time I saw Mads publicly announce the now cut primary constructor syntax and declaration expressions was nearly a year ago at NDC London. At the time the features were announced with a number of disclaimers that they may not actually ship. I think in future it may be better for everyone to take those disclaimers with more than just a pinch of salt.


Tags:
Categories: C# | F# | .Net
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