Conjunction of synchronous and asynchronous languages for reactive programming

In the framework of reactive programming, we examine the complementarity between the synchronous and asynchronous approaches. Some issues related to the synchrony assumption of the Esterel language are highlighted. We claim that it is possible to obtain asynchronous features (e.g. lengthening actions and memorized events) while keeping the benefits of the synchronous approach (e.g. proofs on the correctness of behaviors). From this comparison, principles are derived in order to translate the asynchronous Electre programs into the common code of the reactive languages (using the Esterel synchronous language). Furthermore, the idea of a mixed programming style is presented. It makes it possible to write programs consisting with a synchronous part together with an asynchronous part. Some aspects of this new approach called ambisynchronism are illustrated through an example.