Lambdafication (was Re: Default methods in JFX-8)

Tom Schindl tom.schindl at bestsolution.at
Mon Oct 7 07:21:51 PDT 2013 

... I can't see any real improvement for using lambdas beside that you
killed off warnings which could be fixed otherwise as well.

So I really don't get what it would help us beside making e.g. RoboVM
our sole chance to get FX on iOS harder to maintain.

Tom

On 07.10.13 16:16, Sven Reimers wrote:
> Ok. So I will file a P4 saying Lambdafication for Controls
> and send the diff to Richard/Kevin/Jonathan to be attached..
> 
> should I base the change on b110 (master)?
> 
> I could create a public bitbucket branch based on master and add my changes
> there - better idea?
> 
> What approach is most simple for review?
> 
> Should I split test and library code changes?
> 
> -Sven
> 
> P.S. Shall I try to get this done as well for other modules? Which would be
> preferred? (Just in case I have some more time to spend)
> 
> 
> 
> On Mon, Oct 7, 2013 at 1:26 PM, Kevin Rushforth
> <kevin.rushforth at oracle.com>wrote:
> 
>> **
>>
>> 5. Should we enable more -Xlint warnings in OpenJFX build?
>>
>> 6. Any chances anything of this can still go in 8 (e.g. get rid of warnings
>>
>>
>> We have 2 weeks where we can still accept P4-P5 bugs into FX 8, and
>> getting rid of warnings would be a P4 bug. I guess it depends on how
>> intrusive the changes are and whether someone has time to review it in the
>> next two weeks.
>>
>> -- Kevin
>>
>>
>>
>>
>> Sven Reimers wrote:
>>
>> Ok. So here are the results of trying to add lambda and diamond to the
>> controls module:
>>
>> 1. A lot of generics and typing to be fixed (esp. in tests). Seems you can
>> get  some anonymous inner classes type checked by the compiler, but not the
>> lambda equivalent.. very interesting.
>>
>> 2.  279 Files modified (including tests)
>>
>> 3. A lot of the automatic replacements could probably be nicer e.g.
>>
>> ft.setOnFinished(new EventHandler<ActionEvent>() {
>>                         @Override public void handle(ActionEvent
>> actionEvent) {
>>                           getChildren().remove(tm.textNode);
>>                         }
>>                     });
>>
>> was replaced to:
>>
>> ft.setOnFinished((ActionEvent actionEvent) -> {
>>     getChildren().remove(tm.textNode);
>> });
>>
>> most unobtrusive code probably:
>>
>> ft.setOnFinished((actionEvent) -> getChildren().remove(tm.textNode));
>>
>> 4. A lot of illegal forward reference errors - these were result of missing
>> this in the automatic transformation from anonymous inner to lambdas (seems
>> the rules are not identical - you have to add "this." as prefix if using
>> lambdas - not sure this is the expected way it should work)
>>
>> 5. Should we enable more -Xlint warnings in OpenJFX build?
>>
>> 6. Any chances anything of this can still go in 8 (e.g. get rid of warnings
>>
>> 7. Probably more things I just can't think of at the moment...
>>
>> How to take this forward? If there is interest in the change I could make
>> available...
>>
>> Comments? Ideas?
>>
>> -Sven
>>
>>
>>
>> On Fri, Oct 4, 2013 at 2:19 PM, Sven Reimers <sven.reimers at gmail.com> <sven.reimers at gmail.com> wrote:
>>
>>
>>
>>  Oh and btw - would you go for lambda with or without additional type info
>>  before parameter name?
>>
>> -Sven
>>
>>
>> On Fri, Oct 4, 2013 at 2:05 PM, Sven Reimers <sven.reimers at gmail.com> <sven.reimers at gmail.com>wrote:
>>
>>
>>
>>  Ok. Here you go...
>>
>> I just did an inspection run for the controls module and my IDE came up
>> with  (drum roll) 888 possible lambda conversions..
>>
>> Looking through them I discovered that usage of <> (aka diamond syntax)
>> is   not used (or at least not used a lot) in at least the controls
>> modules. My IDE showed me 1171 occurrences.
>>
>> Is there a good reason not to use diamonds?
>>
>> Will now try to apply all those changes and figure out if this still
>> builds... up next: go through the other modules...
>>
>> -Sven
>>
>>
>> On Fri, Oct 4, 2013 at 1:35 AM, Richard Bair <richard.bair at oracle.com> <richard.bair at oracle.com>wrote:
>>
>>
>>
>>  Brian was telling me at J1 that whether parallel gets you performance or
>> not depends on the size of the collection and the complexity of the work to
>> perform. There is definitely a point at which parallel helps -- and a point
>> at which it hurts.
>>
>> Richard
>>
>> On Oct 3, 2013, at 3:33 PM, Hervé Girod <herve.girod at gmail.com> <herve.girod at gmail.com> wrote:
>>
>>
>>
>>  Here is a nice example, taking advantage of the ease of going
>>
>>
>>  parallel. Apparently the performance without parallel will also further
>> improve.http://blog.hersen.name/blog/2013/10/01/project-lambda-it-was-worth-the-wait/
>>
>>  Hervé
>>
>> Sent from my iPad
>>
>>
>>
>>  On 4 oct. 2013, at 00:20, David Grieve <david.grieve at oracle.com> <david.grieve at oracle.com>
>>
>>  wrote:
>>
>>
>>  And what about Stream? I like the declarative code that comes from
>>
>>
>>  using Stream and I can see places in the code where Stream could be used,
>> but I wonder about its performance relative to iterators and/or enhanced
>> for loops.
>>
>>
>>  On Oct 3, 2013, at 4:45 PM, Richard Bair <richard.bair at oracle.com> <richard.bair at oracle.com>
>>
>>  wrote:
>>
>>
>>   Hello, OpenJFX Community.
>>
>> There's a question about using Java 8 features in FX.
>>
>> I've been working on the support for InputMethods in JFXPanel which
>>
>>
>>   is an important feature for many users who speak hieroglyphic languages.
>>
>>
>>   The issue is tracked under:
>>
>>
>>   https://javafx-jira.kenai.com/browse/RT-13248
>>
>>   In order to have a high-quality support we need to change
>>
>>
>>   javafx.scene.input.InputMethodRequests interface and introduce 3 new
>> methods. This is not needed for pure FX applications right now, but
>> absolutely required for InputMethods in the JFXPanel. However, the
>> interface is public and it was present since FX2.0, so changing it would
>> become a breaking change. So the only way to avoid the problem is using the
>> default methods. Those would return some stub values, the JDK is OK with
>> that, as it would not crash or throw exceptions, but text composition would
>> not work correctly.
>>
>>
>>   I know that we want to avoid using the Java 8 features in the
>>
>>
>>   JFX-8, so I wanted to ask - is it OK to use the default methods here?
>>
>>
>>   If you are staying away from JDK8 features for the JFX78 backport,
>>
>>
>>   don't worry.  There are more issues with new JDK8 APIs than with the new
>> language features.
>>
>>
>>   For example there were default methods put into some collections
>>
>>
>>   classes that we solved by pushing them down to the first implements.  But
>> the Date and Time picker depends on the new time package.  The threeten
>> backport won't be updated until after 8 ships, so that has been removed so
>> far.
>>
>>
>>   I'de be interested to know what a wholesale lamdaization would
>>
>>
>>   result in speed wise and code size wise (both source and compiled).  From
>> what I can tell the IDEs can lambda and de-lambda fairly easily, so it jsut
>> makes the backport more of a busy work proposition.  If there were
>> performance gains it would also make a great front page story in the next
>> java magazine or a case study..
>>
>>
>>   After having used Lambda's for JavaOne, I'd love to make the
>>
>>
>>   conversion, even if in the end the performance was the same, because the
>> savings in noise in the Java files is so big. At one time I just took the
>> concurrent classes and lambda-ized them to measure the impact on those
>> classes. You could maybe pick a package and just lambda-ize that one
>> package and see what happens in terms of size reduction. We might see:
>>
>>
>>    + A reduction in the overall class size (not pack-200'd)
>>  - An increase in startup time (have to spin up synthetic classes
>>
>>
>>   created at usage time)
>>
>>
>>    +/- And increase or decrease in performance
>>  + A decrease in source code
>>
>> It would be interesting to get some data for these points and see
>>
>>
>>   what effect lambda's have. Especially if an IDE can just do it in bulk…
>>
>>
>>   Richard
>>
>>
>>            --
>> Sven Reimers
>>
>> * Senior Expert Software Architect
>> * NetBeans Dream Team Member: http://dreamteam.netbeans.org
>> * Community Leader  NetBeans: http://community.java.net/netbeans
>>                               Desktop Java:http://community.java.net/javadesktop
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>>
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>>
>> Join the NetBeans Groups:
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>>
>>
>> --
>> Sven Reimers
>>
>> * Senior Expert Software Architect
>> * NetBeans Dream Team Member: http://dreamteam.netbeans.org
>> * Community Leader  NetBeans: http://community.java.net/netbeans
>>                               Desktop Java:http://community.java.net/javadesktop
>> * Duke's Choice Award Winner 2009
>> * Blog: http://nbguru.blogspot.com
>>
>> * XING: https://www.xing.com/profile/Sven_Reimers8
>> * LinkedIn: http://www.linkedin.com/in/svenreimers
>>
>> Join the NetBeans Groups:
>> * XING: http://www.xing.com/group-20148.82db20
>> * NUGM: http://haug-server.dyndns.org/display/NUGM/Home
>> * LinkedIn: http://www.linkedin.com/groups?gid=1860468
>>                    http://www.linkedin.com/groups?gid=107402
>>                    http://www.linkedin.com/groups?gid=1684717
>> * Oracle: https://mix.oracle.com/groups/18497
>>
>>
>>
>>
> 
>

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