language parallax

I’m frantically trying to nail down an example to use at OOPSLA in just a week and a half. I procrastinated for a while on learning about BPEL, which was what I had intended to use as my “domain specific language”.

I’m using Eclipse’s BPEL editor, which is built on EMF and all sorts of other hefty doodads. There are definitely still a few bugs, but overall it’s been fun working with it.

The challenge now is to find a good example to use with my project. One issue is that I haven’t yet found a really compelling BPEL sample. If I had that, I could better visualize my “projection” of BPEL onto a java-based implementation.

In this case, the project, evolve, and co-evolve functions would really be taking the place of using a generic BPEL “engine”. That makes sense to me as an alternative way to think about what an “engine” should look like. The end result of using code generation techniques is that there would be a lot less “meta” code on the “engine” side. Rather, the entire development process/toolset is the “engine”. The concrete (generated) java would actually contain a more literal representation of a particular BPEL instance, rather than manipulating a BPEL model object. In addition to making this code easier to understand for a person writing/maintaining/debugging a particular application, it would significantly reduce the number of dynamic, runtime lookups needed to execute the logic.

The conceptual problem I have is that the project as originally designed matches a “model” expressed in a domain-specific language with the concrete platform-specific artifacts that implement it. I’m not sure that the BPEL example is the same. Hopefully this will become clear in the next day or two. A good set of BPEL examples would really help…