VAlloy – Virtual functions meet a relational language

Abstract

We propose VAlloy, a veneer onto the first order, relational language Alloy. Alloy is suitable for modeling structural properties of object-oriented software. However, Alloy lacks support for dynamic dispatch, i.e., function invocation based on actual parameter types. VAlloy introduces virtual functions in Alloy, which enables intuitive modelling of inheritance. Models in VAlloy are automatically translated into Alloy and can be automatically checked using the existing Alloy Analyzer. We illustrate the use of VAlloy by modeling object equality, such as in Java. We also give specifications for a part of the Java Collections Framework.