New Tech Report: A Safe and Practical Decoupling of Aspects with Join Point Interfaces
Eric | May 18, 2012We have made available a new Technical Report giving information about the current state of the art of our programming language for Join Point Interfaces:
In current aspect-oriented systems, aspects usually carry, through their pointcuts, explicit references to the base code. Those references are fragile and give up important software engineering properties such as modular reasoning and independent evolution of aspects and base code. In this work, we introduce a novel abstraction called Join Point Interfaces, which, by design, supports modular reasoning and independent evolution by decoupling aspects from base code and by providing a modular type-checking algorithm. Join point interfaces can be used both with implicit announcement through pointcuts, and with explicit announcement, using closure join points. Join point interfaces further offer polymorphic dispatch on join points, with an advice-dispatch semantics akin to multi-methods. In this work, we show how our proposal solves a large number of problems observed in previous related approaches. We have implemented join point interfaces as an open-source extension to AspectJ. A first study on existing aspect-oriented programs supports our initial design in general, but also highlights some limitations, which we then address by introducing parametric polymorphism and a more permissive quantification mechanism. As a result, join point interfaces are a safe and practical way of decoupling aspects.
