1.3 Action semantics and Syntax Definition Formalism (SDF)

As mentioned above, the descriptions in original action semantics are still too language-specific, because lexical symbols are directly embedded. When the language is changed, all these symbols, scattered in the description, have to be changed accordingly. Even worse, sometimes it is the overall appearance of those structures that differs. Even if the semantics is the same, migrating from one language to another results in the change of the whole description.

The way to make action semantics even more modular and reusable is to separate the definition of semantics from that of language-specific constructs. This issue is recently proposed, and nicely introduced in [Mos02].