Action Language Metamodel

I've been pondering the action language metamodel the last couple of days. For reseach, I've printed out the in-depth SMALL paper from back in 97 and xeroxed the two page summary from Executable UML as well as my SCRALL notes.

Goals of this action language are:

1. Emphasize parallel processing and data flows.
2. Ensure that the language is as easy to read as the class and state models.
3. Support a full range of data types and domain bridge mechanisms.
   

I'm really impressed with the quality of the SMALL paper. I will probably just implement it straight out. But how?

I certainly need to model action behaviors (link, create, write attribute, etc.) as primitive operations in the class and state metamodel subystems. For now I will just imagine these as domain functions with appropriate signatures. Example:

::Unlink(object_id1, object_id2, rnum)

Clearly we need a lex-yacc generated parser, which means I need to write up a full grammar. I'm thinking that the intermediate representation produced by the parser will populate an action language metamodel - yet to be built.

So when action language is entered, it will be parsed and the action language metamodel will be populated. When a block of action language is triggered at run-time, the action language metamodel will invoke the primitive operations with appropriate parameter values.

The lex-parser and primitive ops are the easy parts, so I will save those for last. I hope to post progress here in the coming days.

It's a nice day for a walk so I'm heading to the local cafe to ponder further.