A Design Pattern to Build Executable DSMLs and Associated V&V Tools

Model executability is now a key concern in model-driven engineering, mainly to support early validation and verification (V&V). Some approaches allow to weave executability into metamodels, defining executable domain-specific modeling languages (DSMLs). Model validation can then be achieved by simulation and graphical animation through direct interpretation of the conforming models. Other approaches address model executability by model compilation, allowing to reuse the virtual machines or V&V tools existing in the target domain. Nevertheless, systematic methods are currently not available to help the language designer in the definition of such an execution semantics and related tools. For instance, simulators are mostly hand-crafted in a tool specific manner for each DSML. In this paper, we propose to reify the elements commonly used to support state-based execution in a DSML. We infer a design pattern (called Executable DSML pattern) providing a general reusable solution for the expression of the executability concerns in DSMLs. It favors flexibility and improves reusability in the definition of semantics-based tools for DSMLs. We illustrate how this pattern can be applied to ease the development of V&V tools.