Aspects and Polymorphism in AspectJ

Erik Ernst
Dept. of Computer Science,
University of Aarhus
Åbogade 34, DK-8200 Århus N
Denmark

David H. Lorenz
College of Computer & Information Science,
Northeastern University
360 Huntington Avenue 161 CN
Boston, Massachusetts 02115 USA

Supported in part by the National Science Foundation (NSF) under Grant No. CCR-0098643 and CCR-0204432, and by the Institute for Complex Scientific Software at Northeastern University.

Abstract:

There are two important points of view on inclusion or subtype polymorphism in object-oriented programs, namely polymorphic access and dynamic dispatch. These features are essential for object-oriented programming, and it is worthwhile to consider whether they are supported in aspect-oriented programming (AOP). In AOP, pieces of crosscutting behavior are extracted from the base code and localized in aspects, losing as a result their polymorphic capabilities while introducing new and unexplored issues. In this paper, we explore what kinds of polymorphism AOP languages should support, using AspectJ as the basis for the presentation. The results are not exclusive to AspectJ--aspectual polymorphism may make aspects in any comparable AOSD language more expressive and reusable across programs, while preserving safety.