On the Oslo team, we think of three kinds of models:
Drawings: This is modeling to communicate from human to human, e.g. on a white board or in Visio. An architecture diagram in a design document is an example of such a thing.
Model-Assisted: This is modeling where we’re talking to a computer, most often to generate code, e.g. the .edmx file used by Visual Studio to generate C# data access code.
Model-Driven: Here we’re also communicating from a human to a computer, but instead of doing it at development-time to generate code, the model is actually used at run-time to drive a run-time, e.g. a Workflow definition to drive the Workflow engine.
The M family of languages is meant for all kinds of things, from executable models, e.g. defining a workflow and executing it via the Workflow runtime, to allowing a business person to express something in a language, either visual or textual, that they understand so that it can be communicated as formally as desired to another human. As an example of the latter, Claudio Perrone has implemented a DSL in MGrammar for Behavior-Driven Development.
It is amazing to me how many of these little DSLs have popped in M just since the PDC. Keep ’em coming!
Justin Bailey has built a little language in MGrammer to create tasks and even better, he’s provided a very tutorial on how he did it. Following along with him would make a great way to learn the basics of Mg. Plus, I love his conclusions:
“Mg is clearly a powerful technology for defining languages. The above is a trivial use, but already we have bypassed most simple file parsing techniques. Quoted strings and balanced parentheses are the bane of non-parsing techniques and it appears that Mg will be placing those abilities within reach of most .NET developers.”
Oh my lord above. I have been working towards last week for about 3.5 years altogether. It started with an incubation in the Connected Systems Division (CSD — the folks that own WF, WCF, BizTalk, etc) doing work to see if modeling was a feasible way to build applications and we just announced the work so far along these lines at the PDC last week. It’s called “Oslo” and here are the top places you should look to get up to speed on it:
