Translation polymorphism in Object Teams

In this paper we present the mechanisms of lifting and lowering which have been incorporated into recent programing languages. In these languages, lifting and lowering are key features in the integration of static, class based inheritance and instance based composition with delegation. We present the embedding of these concepts into our model Object Teams. We elaborate the details of rules and constraints at the type level, which give to the approach the capability of non-invasively integrating modules with different inheritance structures. These rules setup a new kind of substitutability called translation polymorphism. We show how translation polymorphism integrates with subtype polymorphism. By generalizing over the presented techniques we conclude that lifting opens a second dimension for dispatch in object-oriented languages, be supplementing method dispatch with instance dispatch.