Rule-based Object Coordination

. We discuss a framework in which the traditional features of objects (encapsulation, communication, etc.) are enhanced with synchronization and coordination facilities, using the declarative power of rules. We propose two interpretations of rules, one re-active and the other proactive, corresponding to different kinds of interactions between the rules and the objects. Finally, we consider the problem of capturing domain specific knowledge within a general coordination framework, for which constraints offer a promising direction of research. keywords: objects, rules, coordination, constraints. 1 Introduction Object-oriented Programming (OOP) is meant to provide an integrated framework for a technology of software components [20]. In OOP languages (such as Smalltalk and C++), objects have an interface that specifies applicable operations, and have a local state shared by the objects' operations. Variables representing the internal state of the object are called instance variables and ..