DVispatch: A Visual Language with Distributed Rewriting

Our figure-rewriting visual language is extended by a general method so that it rewrites figures distributed on multiple hosts. With this language, network applications or distributed systems can be built simply by drawing figures as a graphical code on a single host. At run-time, the code is partitioned according to the number of target hosts and distributed on them. The partitioned codes then start running distributively and asynchronously, so as to simulate, as a whole, the behavior of the code in the original single-host language. Conversely speaking, a programmer can design and test the distributed behavior of the program by working on the code on a single host. With rewriting rules reflecting the locality of operations, describing distributed systems in such a visual geometrical language makes it easy to grasp the topological structure of their algorithm. Furthermore, geometrical coding of distributed resources enables finergrained control of resources than the conventional models.