M.: Finally, a comparison between Constraint Handling Rules and Join-Calculus

Abstract. We provide a comparison between Constraint Handling Rules and Join-Calculus. Constraint Handling Rules is a concurrent constraint programming language originally designed for writing constraint solvers. Join-Calculus is a process calculus designed to provide the programmer with expressive concurrency abstraction. The semantics of both calculi is based on the Chemical Abstract Machine. Hence, we expect that both calculi share some commonalities. Surprisingly, both calculi have thus far been studied independently, yet we believe that a comparison of these two independent fields of study is long overdue. This paper establishes a first bridge between Constraint Handling Rules and Join-Calculus as a basis for future explorations. Specifically, we provide examples showing that Join-Calculus can benefit from guarded constraints and constraint propagation as found in Constraint Handling Rules. We provide a com-pilation scheme for such an enriched Join-Calculus by applying the con-straint matching methods of the refined operational Constraint Handling Rules semantics.