PROGRESS: A VHL-Language Based on Graph Grammars

A. Schürr

	   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 REwriting 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
	   ENvironment 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.