Monday, October 01, 2012

Current Development and Future Plans for Xtext and Xtend

It has been a couple of weeks now since we released Xtext and Xtend with Eclipse Juno. Time for an update on what we are doing and where we want to go. In the following I describe the main new topics the team is working on. In addition to what is described below there is of course also a lot of maintenance work we are doing, i.e. fixing bugs and improving the core framework. Also we are doing some awesome work for customers, which I’m not allowed to talk about (But, yes, you can hire us. Even the whole team!).

Editors For Other Platforms

We are experimenting with support for other IDE-platforms than Eclipse. The first platform we are looking at right now is the web, more concrete Orion. Other platforms we want to look at are Netbeans, Xcode, Visual Studio and IntelliJ. Also basic configuration settings for TextMate and the like could be something we will be looking at.
Which one do you think is most interesting?
This part of our work is funded by Zukunftsprogramm Wirtschaft

Improved Type System

The type system and linking for Xbase-based languages (Xtend falls into this class) is currently redeveloped. Although the existing one does a decent job it has some architectural flaws which makes it too slow when working with bigger files. The new one is fast and it can do even more and cooler things. Type inference, for instance, now uses control flow analysis. That is you can write the following:
val myMap = newHashMap
myMap.put(23, new StringBuilder)
myMap.put(42, "some string")
// myMap is of type Map<Integer, CharSequence> by now
There are some other new features, which are possible with the new typesystem and even more importantly it will fix the outstanding typing bugs and be a solid foundation for future improvements. I'm sure there will be a blog post about the details in the next couple of weeks.


Xtend gets a new formatter. I’m already using it on a daily basis and must say that it works very well. Especially with a language like Xtend which is syntactically much more flexible than Java, you need to look into language idioms to make sure a formatter does what you expect. There will also be a preference page to adjust formatting settings, but it won’t have as many options as the Java formatter in the beginning. Would be nice to have some more beta testers and feedback. What kind of options do you want to see?
Although we are implementing the formatting for Xtend now, we plan to have a new or at least an improved API for all Xtext languages. And of course the formatting for the expression goes into Xbase.

Active Annotations

Active Annotations allow you to participate in the translation step from Xtend to Java source code. It’s a bit like Java’s annotation processing but much more flexible and less complicated to integrate at the same time. You basically declare an annotation and implement a processing method, where you define how to translate annotated Xtend code to Java. I'll write a separate blog post on this.
Also Sebastian is giving a sneak-preview on Active Annotations tomorrow at JavaOne and the feature will play an important role in the session Web Development with GWT and Xtend Olli and I are giving at EclipseCon in a couple of weeks.

Release Plans

Currently the overhauled type system has highest priority and we are targeting a release as soon as it is done. We hope to have it in December this year. That release will contain the formatting and might have an @Beta-flagged prototype for Active Annotations included. We plan to have a prototype for Xtext & Orion later this year as well, maybe the team can even give a so demo during their EclipseCon talk.

Additional Topics

I want to make contributing simpler. The idea is to provide a one click download, which materialises a working IDE, workspace and target platform on your box. The git repository should already be connected with our gerrit instance. Also we want to start writing breaking and ignored unit tests for defects so potential contributors can easily reproduce a problem and see how our test framework works. Let's see if we can make contributing and fixing bugs simple and fun.
Another topic is to provide an alternative for debugging Xbase-languages. Currently they work through JSR-045 which is great as long as you run your code in a standard JVM. Unfortunately JSR-045 isn't supported by Android's Dalvik-VM or GWT's new SuperDevMode. We need to come up with a solution for this as well.
Finally I want to mention that there is now a package for "Java and DSL Developers" on the Eclipse download page. It doesn't have a neat welcome page so far but it's a one-stop-shopping for people who want to get started with Xtend or Xtext (or both).