The Action Environment

When writing semantic descriptions of programming languages it is highly desirable to reuse descriptions of constructs from previous language descriptions. This is usually not possible without adaptations, due to the lacking modularity of the formalism used. In [3] Doh and Mosses proposed organizing language descriptions such that each construct is described in a separate module, which promotes reuse. They used Action Semantics [5] and ASF+SDF [4] as description language, but experience showed that the notation was too cumbersome, so we developed the ASDF language, which is tailor-made for writing action semantic descriptions (ASDs) of single language constructs. Here we will demonstrate an environment which supports working with ASDF modules.