What will be coming in Xtext/Xpand/Xtend in June

If you are interested in MDD and DSLs on the Eclipse platform, you have of course heard about the upcoming release of Xtext and the accompanying tools. If not, let me give you my view on what will come, and summarize the two most important points. At the core of the new stuff is XBase, an expression language. It can be reused is DSLs, and it is part of Xtend2.

Xtend2 is basically a re-implementation of the old (i.e. current :-)) Xpand and Xtend. It can be used for model-to-model transformation as well as for code generation. A cleaned-up version of Xpand's template syntax is embedded in special Xtend strings. Xtend itself is a "streamlined Java" with higher-order functions, type inference and closures. A really big benefit of Xtend2 compared to the current stuff is that the tooling is implemented with Xtext, and hence is much better quality than the current one. This will be a significant step forward for generator and transformation developers.

XBase is part of Xtend, but it can also be embedded in DSLs. Strictly speaking, you don't *embed* Xbase, rather you make your own grammar inherit from Xbase, so you can reuse the expressions from Xbase in your own DSL. Since basically every (more interesting) DSL has expressions, this simplifies life quite a bit. Xbase is tightly integrated with the JVM and its type system -- it is not yet completely clear to me what this will mean for DSLs whose expressions are not related to JVM types. We'll see.

In addition to these two major steps forward, there are of course any number of bug fixes and improvements. Some small, some a bit bigger, but they are incremental evolutions of what has been possible with the existing Xtext. The improvements
regarding performance and memory consumption are quite significant.

Obviously, I haven't done a lot of real work with this stuff so far, so I am not able to talk from actual experience. But what I have seen so far looks really good and makes me look forward to working with the new release.

Xtext with Xtend, and of course, also MPS with BaseLanguage, clearly shows that language workenches are mature: you can absolutely implement "real" programming languages. These technologies have a great future ahead :-)  permalink