This paper gives a semantics for discrete-event (DE) models that generalizes that of synchronous/reactive (SR) languages, and a continuous-time (CT) semantics that generalizes the DE semantics. It shows that all three semantic models can be used in actor-oriented composition languages, and that despite the fact that CT is the most general, there are good reasons for using each of the more specialized semantics. Moreover, because of the generalization relationship between them, these three models of computation (MoCs) compose hierarchically in arbitrary order. We describe a design system that supports arbitrary combinations of these three MoCs, leveraging the actor abstract semantics of Ptolemy II. Categories and Subject Descriptors D.2.2 [Software Engineering]: Design Tools and Tech
Edward A. Lee, Haiyang Zheng