Garp: a graphical/textual language for concurrent programming

Concurrent systems in which the number of processes and their interconnections can change dynamically suffer from the problem of ensuring that process interconnections are correctly maintained at all times. We propose a hybrid solution to this problem in which processes are described textually, but interconnections are described graphically using a graph grammar to constrain the legal sets of processes and interconnections that the system may evolve. This paper discusses GARP, a hybrid graphical/textual concurrent programming language that acts as a testbed for our ideas, and illustrates its use with an example.