Language Family Engineering with Product Lines of Multi-level Models

Abstract

Modelling is an essential activity in software engineering. It typically involves two meta-levels: one includes meta-models that describe modelling languages, and the other contains models built by instantiating those meta-models. Multi-level modelling generalizes this approach by allowing models to span an arbitrary number of meta-levels. A scenario that profits from multi-level modelling is the definition of language families that can be specialized (e.g., for different domains) by successive refinements at subsequent meta-levels, hence promoting language reuse. This enables an open set of variability options given by all possible specializations of the language family. However, multi-level modelling lacks the ability to express closed variability regarding the availability of language primitives or the possibility to opt between alternative primitive realizations. This limits the reuse opportunities of a language family. To improve this situation, we propose a novel combination of product lines with multi-level modelling to cover both open and closed variability. Our proposal is backed by a formal theory that guarantees correctness, enables top-down and bottom-up language variability design, and is implemented atop the MetaDepth multi-level modelling tool.

Modular language product lines: concept, tool and analysis

“…These requirements stem from our own experience building language families and techniques for their engineering [14,16,26], as well as on an analysis of the literature on language product line engineering [48] and compositional language engineering [55].…”

“…Merlin is not compositional, but it overlaps all meta-models in a 150 MM, where elements attach formulae stating the configurations they belong to. MetaDepth [14] uses multi-level modelling to define language families, and product lines for their customisation. The proposal is backed by a formal theory that guarantees correctness.…”

“…Product lines permit the compact definition of a potentially large set of products that share common features. This way, earlier works have created product lines of meta-models [14,26] and model transformations [16,66]. However, the former do not consider semantics [14,26], while the latter do not support meta-model variants [66], are hard to extend [16], or are not based on formalisms that enable asserting consistency properties over the language family [16,47].…”