Edelta 2.0: Supporting live metamodel evolutions

Evolving metamodels is a delicate task, both from the programming effort's point of view and, more importantly, from the correctness point of view: the evolved version of a metamodel must be correct and must not contain invalid elements (e.g., dangling references). In this paper we present the new version of Edelta, which provides EMF modelers with linguistic constructs for specifying both basic and complex refactorings. Edelta 2.0 is supported by an Eclipse-based IDE, which provides in this new version a "live"development environment for evolving metamodels. The modelers receive an immediate feedback of the evolved versions of the metamodels in the IDE. Moreover, Edelta performs many static checks, also by means of an interpreter that keeps track on-the-fly of the evolved metamodel, enforcing the correctness of the evolution right in the IDE, based on the flow of the execution of the refactoring operations specified by the user. Finally, Edelta 2.0 allows the users to easily introduce additional validation checks in their own Edelta programs, which are taken into consideration by the Edelta compiler and the IDE.