VDict mobile



language (PROGRES) A very high level language based on
graph grammars, developed by Andy Scheurr
[email protected] and Albert Zuendorf
[email protected] of RWTH, Aachen in
1991.
PROGRES supports structurally object-oriented specification
hierarchies and types of types (for parametricpolymorphism). It also supports declarative/relational
specification of derived attributes, node sets, binary
relationships (directed edges) and Boolean constraints,
rule-oriented/visual specification of parameterised graph
rewrite rules with complex application conditions,
nondeterministic and imperative programming of composite
graph transformations (with built-in backtracking and
cancelling arbitrary sequences of failing graph
modifications).
It is used for implementing abstract data types with
graph-like internal structure, as a visual language for the
graph-oriented database GRAS, and as a rule-oriented
language for prototyping nondeterministically specified
data/rule base transformations.
PROGRES has a formally defined semantics based on
"PROgrammed Graph Rewriting Systems". It is an almost
statically typed language which additionally offers "down
casting" operators for run time checked type
casting/conversion (in order to avoid severe restrictions
concerning the language's expressiveness).
Version RWTH 5.10 includes an integrated environment.
[A. Scheurr, "Introduction to PROGRES, an Attribute Graph
Grammar Based Specification Language", in Proc WG89 Workshop
on Graphtheoretic Concepts in Computer Science", LNCS 411,
Springer 1991].
for
(1993-11-02)