Introducing Lambda Expressions to the Java Programming Language

Alen Ribic will be presenting Java 8 JSR-335 (Lambda Expressions)

18:00 – 19:00 Networking and supper
19:00 – 20:00 Presentation
20:00 onward  Networking


About Alen: He is an avid hacker and programming language design enthusiast. Current area of interest is in understanding complexity of large software systems. Focus is on difficulty of testing and informal reasoning rather than computational complexity. He is working for Oracle South Africa.


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  • mohamed

    Wish more attended

    May 27, 2013

  • Richard K.

    Interesting how Guava which is the subject of the next meetup already has Functions and Predicates

    April 25, 2013

  • Tomasz S.

    Btw If you enjoyed the functional programming part of the presentation there's a brilliant (free) course on coursera on scala which also talks a bit on the theory. Very enjoyable

    April 24, 2013

    • Guillaume B.

      Yes, this is a good course. By the way, I've setup a Scala Jozi meetup group­ . The 1st meetup is yet to be decided as I need to work out logistics, etc...

      2 · April 25, 2013

    • Richard K.

      Good luck. If you need any help, give me a shout. :)

      1 · April 25, 2013

  • Tomasz S.

    very interesting presentation

    1 · April 23, 2013

  • A former member
    A former member

    Sorry I had to leave early, but I didn't expect us to start a bit late and I still had some work to do before the next morning :-)

    Anyway, the talk and examples was interesting and I am happy Java is finally embracing things some of us have taken for granted for many years. I have to agree that Lambda for a strongly OOP focused language must be a real challenge.

    Lucky I come from a Pascal/C/Perl background, so the take-on for me of Lambda in Java should be very natural and "just start to happen" when Java 8 launch.

    I look forward to the next meetup :-)

    2 · April 23, 2013

  • Ashirvaad R.

    Have been looking forward to this one, but as usual delayed at work today so I might be running late for the start ... Apologies!

    April 22, 2013

  • Alen R.

    As promised, here are the links:


    Code we wrote during the session:

    Code where we push the limits of lambda expressions; building lists out of lambdas and beyond":

    Direct link to downloading Java SE ,8 the EA release, with Lambda support:


    3 · April 22, 2013

  • Kayle M.


    1 · April 22, 2013

  • Tomasz S.

    So where is the piz^H^H^H everybody?

    April 22, 2013

  • A former member
    A former member

    I'm in Texas for the next 2 weeks

    April 21, 2013

  • Alen R.

    Final agenda for the talk:

    * What's all this lambda (λ) speak about?
    - Brief History
    - Informal introduction to Lambda calculus
    * Lambda expressions and Java
    * Lambda syntax and semantics in Java (JSR 335)
    * Time to write some code
    * JSR 335, work in progress

    Food and drinks will be provided.

    The url to the presentation will be available after the talk.

    See you all there!


    1 · April 21, 2013

  • Simanga M.

    I'm glad, i found you

    1 · April 12, 2013

  • Alen R.

    To get an idea from the audience, I list below a few possible things I can talk about or demo in no particular order. Provide your comments below, and I'll tailor the talk towards the demand.

    - We take exiting Java code and turn it into smaller, more expressive code that is simpler to read and maintain.

    - Introduction to Lambda Calculus, the formal mathematical model that underpins Closures/Lambda Expression in programming languages - The Java Type System, type checking, Rules to support Lambda Expressions

    - The Scoping Rules, bound, unbound variables, shadowing and effects of mutation on scoping

    - Beyond Java 8, potential future enhancements to improve the Lambda Expressions support in Java (Feedback welcome!)

    Any other suggestions welcome.

    3 · March 26, 2013

    • Alen R.

      So by polymorphic lambdas, I mean you can do more than saying that my lambda is of the following type: "Integer -> Integer" or "A -> A" where A is one "specific" type. You can actually say: <? extends Number> -> <? extends Number>, to mean polymorphic on "related generic types"!

      April 5, 2013

    • Guillaume B.

      In Scala, you can do this using a typeclass, see http://stackoverflow....­. I am looking forward to your talk.

      April 5, 2013

  • Tomasz S.

    beware, cause i will be there ;]

    1 · March 27, 2013

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