Rewriting Constraint Models with Metamodels

TL;DR

This paper introduces a general pivot metamodel for constraint models that facilitates rewriting, translation, and optimization across various constraint programming languages, independent of specific language syntax.

Contribution

The paper presents a novel, language-independent metamodel for constraint models enabling flexible rewriting and transformations across diverse constraint languages.

Findings

Metamodel captures common features of constraint models.

Rewriting operations are language-agnostic and manipulate metamodel instances.

Framework supports semantic-preserving transformations across languages.

Abstract

An important challenge in constraint programming is to rewrite constraint models into executable programs calculat- ing the solutions. This phase of constraint processing may require translations between constraint programming lan- guages, transformations of constraint representations, model optimizations, and tuning of solving strategies. In this paper, we introduce a pivot metamodel describing the common fea- tures of constraint models including different kinds of con- straints, statements like conditionals and loops, and other first-class elements like object classes and predicates. This metamodel is general enough to cope with the constructions of many languages, from object-oriented modeling languages to logic languages, but it is independent from them. The rewriting operations manipulate metamodel instances apart from languages. As a consequence, the rewriting operations apply whatever languages are selected and they are able to manage model semantic information. A bridge is created between the metamodel space and languages using parsing techniques. Tools from the software engineering world can be useful to implement this framework.