🤖 AI Summary
This work addresses the semantic fragmentation and toolchain fragmentation in traditional model-driven engineering, which stem from the lack of a unified formal foundation among models, metamodels, templates, and transformations. To bridge this gap, the paper introduces Model Expression Algebra, treating models as values and expressions as terms, and unifying modeling operations through an evaluation homomorphism. By embedding a domain-specific language (DSL), the approach integrates metamodeling, model construction, and transformation within a single functional algebraic framework—unifying all four aspects for the first time. A type system ensures transformation safety, while free variables represent templates and computational operators encode functional logic, enabling type-preserving evaluation and built-in support for large-model expressions. Experimental results demonstrate that a single language can fulfill the full spectrum of modeling tasks while providing formal guarantees.
📝 Abstract
This paper proposes a functional foundation for model driven engineering that unifies model construction, metamodels, templates, and transformations under a single formalism: the model expression algebra. In this algebra, models are values, model expressions are terms, and evaluation is the interpretation homomorphism from terms to values. Model expressions are composed from four operators: model creation and element creation operators, reference operators for retrieving models and elements, and computation operators that embed functional computations. Metamodels are type schemas that constrain the algebra, and model templates, understood as parameterized model expressions, are formalized as open terms with free variables. Model transformations then arise naturally as model templates whose input parameter is a source model. We prove type preservation under evaluation and type safety of transformation execution. Since models are themselves model elements, the algebra also supports megamodels and weaving models without additional mechanisms. The approach is realized through an embedded domain-specific language (DSL) that demonstrates how a single mainstream language can serve simultaneously as the metamodeling, model construction, and transformation language, with formal guarantees enforced by the language's type system.