Formal interpreters for diagram notations

Abstract

The article proposes an approach for defining extensible and flexible formal interpreters for diagram notations with significant dynamic semantics. More precisely, it addresses semi-formal diagram notations that have precisely-defined syntax, but informally defined (dynamic) semantics. These notations are often flexible to fit the different needs and expectations of users. Flexibility comes from the incompleteness or informality of the original definition and results in different interpretations.The approach defines interpreters by means of a mapping onto a semantic domain. Two sets of rules define the correspondences between the elements of the diagram notation and those of the semantic domain, and between events and states of the semantic domain and visual annotations on the elements of the diagram notation.Flexibility also leads to notation families, that is, sets of notations that share core concepts, but present slightly different interpretations. Existing approaches usually interpret these notations in isolation; the approach presented in this article allows the interpretation of a family as a whole. The feasibility of the approach is demonstrated through a prototype generator that allows users to implement special-purpose interpreters by defining relatively small sets of rules.