Programming with Crosscutting Effective Views

Aspect-oriented systems claim to improve modularity by providing explicit mechanisms that allow modularization of concerns which crosscut the object-oriented decomposition of a system in terms of classes. However, by modularizing concerns which crosscut classes, at the same time the structure and functionality associated with the classes themselves becomes scattered across the implementation of different aspects. This may hamper system understanding in other ways. In this paper we present a system that addresses this issue by allowing a developer to move fluidly between two alternative modular views on the decomposition of the program, editing the program either as decomposed into classes, or alternatively as decomposed into modules that crosscut classes. Thus developers gain the advantages of open classes, without having to give up the ability to edit the program directly in terms of classes.