F# all the things, Java equality, Hole-driven Haskell

  • February 26, 2013 · 5:45 PM
  • This location is no longer available

This month we are delighted to present three first-time BFPG speakers!

If you find yourself stuck outside the venue, please contact Matt on 0431926131.

match C# with Some(F#)

Phil de Joux

If F# is being sold as a niche language, it's being sold short. F# really can do all the things C# can, except perhaps to be generated by tooling wizards. Get your hands on default immutability, first class functions, algebraic data types and persistent data structures, with a compiler that knows your types, makes them generic and gets out of your way.

Phil is a rock climber and hang glider pilot at heart, and a mathematical modeler by training, but he's also been programming C++ and C# for many years. More recently, he's discovered that F# makes his work easier and more enjoyable, and he's used F# in commercial projects, for analysing time-series data in the REPL, pulling in web services with type providers, and distributing messages with mailbox processors. Phil was the technical reviewer for the book Expert F# 3.0, by Don Syme et al.

Value equality for Java

Dylan Just

This talk examines some issues with the equals method in Java, and presents some alternative approaches, including simulating Haskell-style type classes in Java. We'll look at the roles of types and type checking, and what it really means for two values to compare equal.

Dylan is a mad keen functional programmer that loves to code. His hobbies include sticking computers in strange cases and arguing with Erik Meijer on Twitter. He can be found at Ephox yabbering on about types and compulsively recabling the server room. Blog: techtangents.com Twitter: @techtangents

Hole driven development

Greg Davis

When writing Haskell programs, we tend to use lots of polymorphic types. That's good! We can reuse those pieces, thanks to the types. But when implementing polymorphic functions, it can sometimes be difficult to see how things fit together, especially if we don't have a systematic approach.

At a recent Haskell course taught by members of this group, I discovered such an approach, which we call "hole driven development". I'll demonstrate the technique, including some tricks to get help from the compiler. I'll also preview an exciting new language feature which will hit the Haskell platform soon.

 

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  • Phil de J.

    I gave a presentation on F# at http://www.canterburysoftware.org.nz/events/previous-events/august-2013-event/ last night. The slides are up at https://bitbucket.org/philderbeast/fsharptalk. It's the same repo as before with a new tag and quite a few changes in the slide deck. Missing from the Feb BFPG and quite a major plus is that reference types in F# only allow null by opting in otherwise you will be refused with "error FS0043: The type 'XYZ' does not have 'null' as a proper value". Null reference exceptions can be a thing of the past.

    August 7, 2013

  • Rob M.

    I put the tech roundup on vimeo, since I noticed that the past ones get a fair amount of views.
    https://vimeo.com/61000603

    March 4, 2013

  • Phil de J.

    F# all the things slides and a solution for the code snippets are up on https://bitbucket.org/philderbeast/fsharptalk

    March 1, 2013

  • Raahul K.

    Thanks a lot! Any chance of slides(please no powerpoint).

    March 1, 2013

  • Rob M.

    Third talk is up on vimeo:
    Hole DD: https://vimeo.com/60782964
    A cracker. Some of the livelier jesting just missed inclusion - Tony's quip about F# was said before I rolled the camera.

    March 1, 2013

  • Rob M.

    First two talks are up on vimeo:
    F# all : https://vimeo.com/60597962
    Java = : https://vimeo.com/60696694
    3rd talk aiming for tonight

    February 28, 2013

    • Ben K.

      Awesome work, Rob! Thanks for putting in the effort to get these out. :)

      February 28, 2013

  • techtangents

    Also, I just found a gist from Tony Morris that defines equality in scala. https://gist.github.com/tonymorris/4481469

    February 27, 2013

  • techtangents

    Hi, all. Slides and code for my talk are up at https://github.com/techtangents/javaeq

    February 27, 2013

  • Andrew N.

    I was really impressed with all 3 talks. I really enjoyed everyone different experiences with FP.

    February 27, 2013

  • Raahul K.

    Loved the last talk. Great to to be reminded the Scala course is back on.

    February 26, 2013

    • Andrew H.

      The Scala course is awesome. I went in with only a rudimentary knowledge of functional programming and came out with a 100% mark and a very good base level of Scala knowledge to work from.

      February 26, 2013

  • Raahul K.

    The last talk was fantastic .. but it went on very long. Didn't get out of there till 9 pm.

    February 26, 2013

  • Ben K.

    Great night regardless of our little drama with the venue. Thanks to everyone for making this happen. :)

    February 26, 2013

  • Rob M.

    Great talks and good audience banter.

    February 26, 2013

  • Christopherys A.

    Nice to have been there.

    February 26, 2013

  • Darren M.

    Would love to be there - but will be in the other extremity of the earth, ( several hundred kms north of the arctic circle in Tromsø, Norway )

    Will this be recorded by any chance ?

    Cheers. Darren

    February 20, 2013

    • Darren M.

      Cool !! Btw - are you up very very late ? Or very very early? ;-)

      February 20, 2013

    • Ben K.

      Early, but not that early. It is currently 0518 here in Brissy.

      February 20, 2013

  • Darren M.

    :-(.

    February 20, 2013

  • Raahul K.

    Looking forward to hearing more about F#.

    February 19, 2013

  • A former member
    A former member

    I'm afraid that the 26th is my wife's birthday. I won't be able to make it. Very sorry all, have a blast!

    February 14, 2013

  • Rob M.

    Usual video duties assumed

    February 13, 2013

    • Matthew B.

      You're awesome! Thanks, Rob!

      February 14, 2013

50 went

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