MPS Workshop at itemis
Last week, we had a workshop about JetBrains MPS
in Pforzheim. Konstantin Solomatov
, MPS' lead developer, was kind enough to spend a whole week with the team in Pforzheim to teach us MPS to a level of detail where I feel comfortable to start using the tool in real projects (thank you very much, Konstantin!).
We have built a couple of example languages, all of them extensions of Java. Remember that one of the benefits of MPS is the ability to extend existing languages, in particular, the version of Java (called BaseLanguage) they ship with MPS: we have extended Java classes with state machines, we've added pre- and postconditions to Java interfaces, we implemented a new type to represent money and we've built a way to express product line variability for arbitrary languages.
Once we got used to some of the particularities of MPS, working with the tool was actually very productive and comfortable. In the time we had, we got further along than I had expected. JetBrains have done a really good job with making the projecting editor "feel" as much as text as possible. Within a week or two, you can easily get used to working with this approach.
Because MPS is a projectional editor, you can be extremely flexible regarding modularization and combination of languages. The four example languages we have built can be combined arbitrarily in a single program. Of course the drawback is, that programs are not stored as plain text, but rather as an abstract representation (XML). This means, that you can edit MPS programs only with MPS. However, the projectional approach does give you a significant amount of additional flexibility over storing the concrete syntax. In other words: there are many environments where storing the textual syntax is preferable, in which case tools like Xtext
are the better choice. But there are also a number of scenarios where you don't care as much about how programs are stored, and you want to exploit the benefits regarding flexibility that projectional editors deliver. In those scenarios MPS is a very interesting candidate and certainly worth considering (remember, that it is also open source).
In the next weeks, I will continue my evaluation of the Intentional Domain Workbench
to complete my picture about the three most interesting DSL tools out there: Eclipse Xtext
, JetBrains MPS
and the Intentional Domain Workbench
. These tools are different enough to warrant familiarity with each of them. They all have a particular sweet spot regarding where and how they should be used.