Graph pattern matching in progres

Abstract

The work reported here is part of the PROGRES (PROgrammed Graph Rewriting Systems) project. PROGRES is a very high level multi paradigm language for the specification of complex structured data types and their operations. The data structures are modelled as directed, attributed, node and edge labeled graphs (diane graphs). The basic programming constructs of PROGRES are graph rewriting rules (productions and tests) and derived relations on nodes (paths and restrictions). Although graph rewriting systems have successfully been used for specification purposes in many application areas since about 20 years, there was no sufficient tool available for the execution and implementation of graph grammar specifications. Especially, the problem of efficiently searching for a redex for an arbitrary given rewrite rule has been unsolved for a long time. In this paper we propose a new, heuristic, graph based algorithm solving this graph pattern matching problem. This algorithm has been implemented and is used successfully within the PROGRES environment.