Sequence Traces for Object-Oriented Executions

Researchers have developed a large variety of semantic models of object-oriented computations. These include object calculi as well as denotational, small-step operational, big-step operational, and reduction semantics. Some focus on pure object-oriented compu-tation in small calculi; many others mingle the object-oriented and the procedural aspects of programming languages. In this paper, we present a novel, two-level framework of object-oriented computation. The upper level of the framework borrows elements from UML’s sequence diagrams to express the message exchanges among objects. The lower level is a parameter of the upper level; it represents all those elements of a programming lan-guage that are not object-oriented. We show that the framework is a good foundation for both generic theoretical results and practical tools, such as object-oriented tracing debuggers