Declarative definition of contexts with polymorphic events

Abstract

This paper introduces a new model of event handling combining explicitly triggered events with events intercepted with aspect-oriented features. The model supports event abstraction, polymorphic references to events, and declarative definition of events as expressions involving references to events from other objects. We show that this model makes it easy to define a declarative and compositional notion of event-based context. We illustrate these ideas with examples in ECaesarJ, a language with concrete support for our model, and relate the events of ECaesarJ to other event-handling and context-handling models.