An optimizing OCL compiler for metamodeling and model transformation environments

Abstract

Constraint specification and validation lie at the heart of modeling and model transformation. The Object Constraint Language (OCL) is a wide-spread formalism to express constraints in modeling environments. There are several interpreters and compilers that handle OCL constraints in modeling, but these tools do not support constraint optimization, therefore, the model validation can be slow. This paper presents algorithms to optimize OCL compilers to reduce the number of database queries during the validation process by eliminating the unnecessary traversing steps and caching the database queries. Proofs are also given to show that the optimized and the unoptimized code are functionally equivalent. The optimized compiler has been integrated into the Visual Modeling and Transformation System tool and applied to constraints appearing in both metamodels and graph rewriting-based model transformation rules. © 2006 International Federation for Information Processing.