Defining semantic variations of diagrammatic languages using behavioral programming and queries

We present a methodology for describing executable semantics of diagrammatic modeling languages, and an execution engine based on such definition. Under proposed methodology, languages are defined using a set of pairs, composed of a query and a group of mappers. The queries, defined over the language's diagrammatic syntax, return language constructs. These constructs are mapped by the mappers to behavioral programming-based models. Resultant definition is executable, can inter-operate with similar definitions of other languages, and is accessible to practitioners who read code but shy away from transition formulae. We demonstrate our approach by defining a subset of the LSC language, and by implementing an LSC runtime engine based on that definition.