Implementation Techniques for Petri Net Based Specifications of Human-Computer Dialogues

Modern window-based user interfaces are actually a special kind of reactive system, and Petri nets may be fruitfully used to design such user-computer dialogues. This paper describes two techniques allowing to produce an executable system from a Petri net based specification of dialogue, namely interpretation and compilation. We first describe the compiled solution, where the Petri net structure is translated into conventional algorithms and data structures that can be implemented into any conventional event-driven UIMS. We then detail the object-oriented software architecture of an environment based on the interpreted approach, where the net structure is preserved at run-time, and present an original algorithm for interpreting high-level Petri nets in an event-driven environment.