PROGRESS: A VHL-language based on graph grammars

Abstract

The Very High Level language PROGRESS presented within this paper is the first statically typed language which is based on the concepts of PROgrammed Graph RE-writing SyStems. This language supports different programming paradigms by offering procedural and declarative programming constructs for the definition of integrity constraints, functional attribute dependencies, derived binary relationships, atomic graph rewrite rules, and complex graph transformations. Both the language and its underlying formalism are based on experiences of about ten years with a model-oriented approach to the specification of document classes and document processing tools (of the Integrated Programming Support ENviroment IPSEN). This approach, called graph grammar engineering, is characterized by using attributed graphs to model object structures. Programmed graph rewriting systems are used to specify operations in terms of their effect on these graph models. This paper informally introduces PROGRESS” underlying graph grammar formalism and demonstrates its systematic use by specifying parts of a syntax-directed editor for a simple expression language. The construction of a PROGRESS-specific environment with an integrated set of tools is the topic of another paper within this volume (cf./NS 90/).