Groovy Weekly #18

The Easter bunny is delivering the latest Groovy Weekly column!


With your chocolate eggs, you’ll get some bits of functional programming, a tutorial on Groovy traits, details of the JSON serialization performance improvements, and also get the chance of voicing your feedback on things like Groovy’s support of Java 8 lambda syntax, on the Ratpack async support, and more.

Releases

  • groovy-comprehension is a groovy extension module / AST transformation which provides simple list comprehension functionality similar to that of Haskell, Scala or Python. Under the hood it’s a 'monad' comprehension but you don't care about it for use.

Presentations

  • Guillaume Laforge gave a brand new presentation on Groovy, at Devoxx France 2014, covering the novelties in the upcoming Groovy 2.3 release

  • Cédric Champeau spoke about Gradle vs Maven at the Devoxx France 2014 conference last week. The slides are in French, but even if you're not speaking it, you should get some interesting tidbits from the code samples and links

Articles

Tweets

Google+ posts

News

Books

Jobs

  • James Foley is currently looking to network with an experienced (3 years plus) Groovy/Grails Application Developer for an excellent on going contract OR contract to hire scenario. 100% Remote opportunity!

Events

Groovy Weekly #17

Busy conference times:


Greach is over, but we’re lucky to get the next batch of presentations and videos online on the Greach Youtube channel.


The GR8Conf Europe early bird price has been extended for another week.


And Cédric and myself (Guillaume) are heading to the Devoxx France conference to speak about Groovy and Gradle.


While at the same time, the Groovy team is delivering a new beta for the lovely Groovy 2.3 release.


Busy times, I tell you!

Releases

Interviews

  • Interviews recorded at Greach: Alberto Vilches, Russel Winder, Cédric Champeau, Graeme Rocher, Guillaume Laforge, Sébastien Blanc, Corrine Krych and others

Presentations

Articles

Code snippets

Tweets

News

Jobs

Events

Second beta for Groovy 2.3

Hot on the heels of our first beta for Groovy 2.3, here's already a second one!

We've received a lot of feedback, which is really awesome!
Thanks a lot to all those who put the first beta to its pace and reported their findings.

The most important change in this release is that the groovy.jar no longer depends on ASM and Antlr.

It's the first release ever of Groovy where the groovy.jar itself is "jajar-ed" like the groovy-all JAR, which means that the ASM and Antlr libraries are embeded (and translated to a different package) so that you don't need to depend on those libraries in your projects, and run the risk of a version clash with other frameworks or libraries depending on differing versions.

It's an important step for those who wish to have smaller JARs, and who don't want the whole libraries offered by Groovy, but who want to pick up just the components they are interested in.

Please report any problem you might find, in case you're using groovy.jar instead of groovy-all.jar.

Apart from that, several issues have been fixed, regarding traits, generics handling, a problem when running Groovy on Google App Engine.

There is a minor breaking change with regards to whitespace handling in our XML support.

You can check the JIRA release notes to see the issues fixed:

And head to our download area to get the latest and hottest beta:

If you're using Gradle or Maven, we noticed some issues with our deployment process which made the groovy-all.jar lacking a pom.xml file on Central and JCenter. We're working on solving that issue with the JFrog team and we will let you know when it's fixed.

Keep up the feedback coming!

Groovy Weekly #16

After the Groovy knights in Madrid, at the Greach conference, the Groovy team delivers the first beta of Groovy 2.3!


An impressive feature list: including traits, official JDK 8 support, tail recursion, NIO2 module, super fast JSON support, closure type inference, a new markup template engine, and much more.


You will also notice the new documentation shaping up but the Groovy Core team still looks forward to contributions to help with this gigantic task, so don’t hesitate to voice your will to help!


Also double check the new style for GroovyDoc documentation as well as GDK documentation.


In the presentations section, don’t miss the bullet linking to all the excellent presentations given at the Greach conference.

Releases

Presentations

Articles

Code snippets

Tweets

News

Jobs

Events

A beta release for Groovy 2.3

The Groovy team is very pleased to announce the first beta of the Groovy 2.3 release!


Groovy 2.3.0-beta-1 is actually already a feature-complete beta, so the release cycle towards the final version will be very short. Furthermore, Grails 2.4 is looking forward to integrating it rapidly as well for its upcoming major release too! So you can expect a general availability version of Groovy in the coming weeks, as we’ll move directly in “release candidate” mode after this beta. But your feedback, as usual, will be very important for trying out this beta in your respective projects, to tell us about any problem you might encounter.


In this email, below, I’ll give you a few pointers regarding the scope of the release, but we’ll be fleshing out a more detailed release notes document in the coming days and weeks with more information.


Warning: this is a lengthy email, but you’ll get to see all the new stuff and improvements the Groovy team and contributors have been working on!


The key highlights of Groovy 2.3 are:


  • Official support for running Groovy on JDK 8

    This is the first version of Groovy to be officially compatible with JDK 8.

    JDK 8 and its interface default methods introduced some incompatibilities with a few methods of the Groovy Development Kit, so we had to adapt to the situation, introducing minor breaking changes for the affected methods and their outcome.

    Note that we’re not planning to backport the changes to older versions of Groovy, so if you want to run Groovy on JDK 8, you’ll have to upgrade to the shiniest version of Groovy!

  • Traits

    A major highlight for Groovy 2.3 is the introduction of the
    concept of traits.

    Traits are reusable components of behavior that you can make your class implement, and are an additional Object-Oriented concept alongside classes and interfaces.

    Groovy traits are stateful (unlike Java 8 interface default methods).

    They allow the composition of behavior without going into the “diamond inheritance” problem allowing you to decide which behavior prevails upon conflict.

    Traits support inheritance, thus a trait can extend another trait or implement an interface.

    Traits are compatible with static type checking and compilation, as well as our usual dynamic behavior. Trait mixed-in methods are actually “real” methods (ie. visible from Java as well) and not just dynamic.

    Traits can also be implemented at runtime with “as” or with “withTraits” if you just want to add behavior of a trait to an object you’re instantiating.

    You can find more information on traits in the exhaustive
    trait documentation.

  • New and updated AST transformations

    • @TailRecursive on methods adds tail recursion to methods which are recursive and call themselves at the last operation of the method body, which helps blowing up the stack with the recursive calls (GROOVY-6570).

    • @Sortable on classes implement comparison methods for you, according to the declaration order of your properties (GROOVY-6649).

    • @Delegate supports includes and excludes attributes so as to let you decide if certain methods should be included or excluded from the delegation (GROOVY-6329).

  • New NIO module for Java 7+

    On JDK 7 and beyond, you can benefit from the same methods as the ones of File, URLs, the various Stream classes, etc, but for the new NIO2 methods, like Path.

    See
    GROOVY-6377 and the pull request for some further hints of the new methods.

  • Various minor performance improvements across the board, for static compilation, the “invoke dynamic” backend, as well as “normal” dynamic Groovy

  • Drastic JSON parsing and serialization performance improvements

    The Rick / Andrey duo spent a fair amount of time optimizing our JSON support, making Groovy 2.3’s JSON support usually
    faster than all the JSON libraries available in the Java ecosystem.

    With
    JsonSlurper, you’ll be able to set different parser types depending on the kind of input you wish to parse, particularly if you know the size of the payload you expect to parse, or whether you want a more tolerant parser which accepts elements like comments which are not normally supported by the JSON specification (GROOVY-6546).

    On the output front, with
    JsonBuilder and StreamingJsonBuilder, which both use JsonOutput for output generation, the serialization has also been tremendously improved (GROOVY-6554).

  • Closure type parameter inference

    We closed a gap which forced you to type your closure parameters to get correct type inference with static type checking or static compilation enabled. In situations like the following, you would have to explicitly give the type of the parameter, but it’s no longer required:

    ['a','b'].each { it.toUpperCase() }

    In the signature of your methods taking closures as arguments, you’ll also be able to annotate the closure parameter with
    @ClosureParams to give additional hints to the type checker to infer the type of the parameters passed to your closure.

    You can also find more about this in Cédric’s blog post on
    closure parameter type inference.

  • New Markup template engine

    Groovy now has an additional template engine, in the form of the Markup template engine, which gives you a very fast template engine, based on the familiar Markup builder approach and notation, but also offering formatting options (indentation, escaping), internationalization, includes, as well as proposing type checked templates and models.

    More details about the new
    Markup template engine in the documentation (GROOVY-6596), as well as in Cédric’s blog, if you want to learn more about the “behind the scenes” stories!

  • Further Groovysh enhancements


Along with some slightly reduced startup time, Groovysh has seen new improvements in its code-completion capabilities:

  • GroovyConsole enhancements

    It is now possible to configure the font used by the console, and also to be able to run a selected snippet of code reusing the imports defined in your script making it easier to just run quick snippets of your script.

  • JUnit 4 GroovyAssert class

    The venerable
    GroovyTestCase (JUnit 3 based approach) has often been used as a base class for your test classes — unless you’ve been using the Spock testing framework, of course. One of the drawback of this class is that your test classes can’t extend your own classes, but must derive from GroovyTestCase to benefit from the additional assertion methods.

    Groovy 2.3 introduces the JUnit 4-friendly
    GroovyAssert, which is a convenient class offering the usual assertion methods of GroovyTestCase, but in the form of static methods that you can static import in your test class.

    We have not included the myriads of assertEquals method from GroovyTestCase as they have become useless with Groovy’s power assert, but it provides the handy shouldFail*() methods (
    GROOVY-6588).

  • ConfigSlurper

    ConfigSlurper just supported a single “environments” non-configurational conditional block, but you couldn’t let you define your own. With Groovy 2.3 you can also create your own ones too, for instance if you wanted to support “flavors” like OS variants (
    GROOVY-6383).

    In addition, the isSet() / hasSet() combo methods (
    GROOVY-4639) have been added so you can double check if a given node of your configuration has been defined. Before, whether the node wasn’t defined or containing null, you couldn’t differentiate either case easily.

  • @BaseScript class improvements

    @BaseScript is a fairly recent addition in Groovy, and it allowed to annotate a variable in your script to instruct the compiler to use a particular base script class for this script. Now we have another notation which is nicer as you can annotate an import or a package (GROOVY-6592) to indicate that base script class:

    @BaseScript(MyScript)
    import groovy.transform.BaseScript


    Additionally, base script classes can now use any abstract method for the script body. This means that you can implement the run() method to implement specific behavior like setup and tear down in tests (
    GROOVY-6585 and GROOVY-6615).

  • New style for the GroovyDoc documentation of Groovy and the GDK methods

    GroovyDoc has been updated with a new fresh and modern skin that will be part of the future visual identity of the Groovy website. Those style updates are also available by default for your own usage of GroovyDoc, making your own documentation nicer on the eye.

    You can have a look at the
    GroovyDoc documentation for Groovy 2.3.0-beta-1.

    We also took the opportunity to apply the same stylesheet to our “DocGenerator” tool which is responsible for the generation of the GDK documentation, showing the methods the Groovy library adds on top of the JDK classes.

    Please also have a look at the new
    restyled GDK documentation.

  • New documentation

    We are still working on the brand
    new documentation for Groovy (in Asciidoc(tor) format), so you can already have a glimpse at what’s already covered or not.

    We’re looking forward for help for fleshing out the various TBD (To Be Done) sections of the documentation, as it’s a gigantic taks to re-document each and every aspect of the language and its libraries! So please shout if you want to
    contribute to the new documentation! All help is warmly welcome!

  • Dependency upgrades

    • Gradle 1.10 for building Groovy

    • ASM 5.0.1 library for generating our bytecode (also needed for our JDK 8 support)

    • JLine 2.11 and JANSI 1.11 library for Groovysh


Groovy wouldn’t be what it is without your support, your bug reports and feature requests, your contributions and pull requests, so big thanks to all those who contributed to this release in a way or another, including the usual suspects of the core team (Jochen, Paul, Cédric and myself), but also André (documentation, GroovyAssert, Groovy Console), Andres (Config slurper, @Sortable with Paul), Tim, Pascal (ConfigSlurper), Johanes (@TailRecursive), Paolo (new NIO module), Thibault (groovysh), Rick and Andrey (for the JSON support), Jim (base script class), Damien (GroovyDoc / GDK styling), Kenneth and several others I’ve forgotten to mention!


And in honor of this first beta release of Groovy 2.3, Cédric even decided to put his birthday on the same day, so happy birthday Cédric, and great work on this release!


We’re looking forward to your feedback running this beta to its pace!

It’s important to make this 2.3 release rock solid!


Download Groovy 2.3-beta-1 and have a look at the JIRA release notes for additional details on issues and bug fixes closed.


Keep on groovy’ing!


 
© 2012 Guillaume Laforge | The views and opinions expressed here are mine and don't reflect the ones from my employer.