Modules and Updatable Graph Views for PROgrammed Graph REwriting Systems

Andreas Winter, Andy Schürr

           Specification and rapid prototyping of graph manipulating
           software by means of PROgrammed Graph REwriting Systems
           (PROGRES) is a paradigm, which attracts more and more
           interests in various fields of computer science. Nowadays
           produced specifications for process modelling tools,
           database query languages, or Conceptual Graph manipulations
           have a typical size of about 100 printed pages. They suffer
           severely from the lack of any graph rewriting system module
           concept. As a first remedy, we have just developed a module
           concept in the flavor of Modula-2 for our graph rewriting
           language and system PROGRES. It supports a variety of
           programming-in-the-large styles, including the construction
           of Abstract Graph Types. Having made the experience that
           ``full data abstraction'' is in conflict with the visual
           programming paradigm of PROGRES, we are now starting to
           add active database system concepts for the construction of
           updatable abstract graph views.