The PROGRES approach: language and environment

Graphs play an important role within many areas of computer science. Rule-based languages, on the other hand, are well-suited for the description of transformation or inference processes on complex data structures. Why not combining two successful principles in one formalism? This is the common vision of the graph transformation community and the main motivation behind the development of PROGRES, a visual language that supports PROgramming with Graph REwriting Systems. The language PROGRES was developed having the following three design goals in mind: (1) Distinguish between data deenition and manipulation activities and use graph schemata to type-check graph transformation rules. (2) Do not rely on the rule-oriented paradigm for all purposes, but support also imperative programming with control structures. (3) Refrain users from the task to guarantee connuence of deened rules by keeping track of rewriting connicts and backtracking out of dead-end derivations. Its accompanying programming environment ooers assistance for creating, analyzing , compiling, and debugging graph transformations as well as for rapid prototyp-ing activities. Being an integrated set of tools with support for intertwining these activities, it combines the exibility of interpreted languages with the safeness of compiled and statically typed languages.