Isomorphic Types for Open Coordination Systems

Open coordination systems traditionally force pro grammers to use a very limited set of types when com municating. As the system is open nothing is known at creation time about which processes will connect, how many of them there will be and what types they will use. This paper describes the first steps in an architecture to allow open systems, such as Linda, to coordi nate heterogeneous processes using general datatypes. By describing types in terms of products, sums and functions and providing functions that translate between this abstract representation and the concrete representation in the program, types can be trans ferred between programs which have no prior knowl edge of each other’s type systems. Combining this with a type isomorphism algorithm allows types that are not identical but are equivalent to be used in com munications between processes.