Using visitor patterns in object-oriented action semantics

Object-Oriented Action Semantics is a semantic framework for the definition of programming languages. The framework incorporates some object-oriented concepts to the Action Semantics formalism. Its main goal is to obtain more readable and reusable semantic specifications. Object-Oriented Action Semantics provides support for the definition of syntax-independent specifications, due to the way its classes are written. In a previous work, a library of classes ( called LFL) was developed to improve specification reuse and to provide a way to describe semantic concepts, independent from the syntax of the programming language. This paper aims to address some problematic aspects of LFL, and presents a case study, where a specification is built by using the Visitor Pattern technique. The use of this pattern allows a clear separation between the syntax of a programming language and its different semantic aspects.