On dynamically-scoped crosscutting mechanisms

Many crosscutting mechanisms proposed in the literature offer means to restrain aspects to some dynamically-defined scopes. Dynamically-scoped mechanisms are particularly interesting because of the flexibility, expressiveness, and control they give over structural and behavioral changes made by aspects. Since the nature of dynamic scopes as well as the scoping mechanisms themselves greatly vary among proposals, It is relatively complex to compare them. This paper aims at filling this gap by proposing a first characterization of dynamically-scoped crosscutting mechanisms, hence providing a reference frame for comparing different approaches. As a result, this work clarifies some differences between related approaches, suggests possible tracks for further exploration of the design space of such mechanisms, and discusses some issues raised by dynamically-scoped aspects.