Engineering a ROVER language in GEMOC STUDIO & MONTICORE: A comparison of language reuse support

Domain-specific languages (DSLs) improve engineering productivity through powerful abstractions and automation. To support the development of DSLs, the software language engineering (SLE) community has produced various solutions for the systematic engineering of DSLs that manifest in language workbenches. In this paper, we investigate the applicability of the language workbenches GEMOC STUDIO and MONTICORE to the MDETools’17 ROVER challenge. To this effect, we refine the challenge’s requirements and show how GEMOC STUDIO and MONTICORE can be leveraged to engineer a Rover-specific DSL by reusing existing DSLs and tooling of GEMOC STUDIO and MONTICORE. Through this, we reflect on the SLE state of the art, detail capabilities of the two workbenches focusing particularly on language reuse support, and sketch how modelers can approach ROVER programming with modern modeling tools

Constraint-based run-time state migration for live modeling

Live modeling enables modelers to incrementally update models as they are running and get immediate feedback about the impact of their changes. Changes introduced in a model may trigger inconsistencies between the model and its run-time state (e.g., deleting the current state in a statemachine); effectively requiring to migrate the run-time state to comply with the updated model. In this paper, we introduce an approach that enables to automatically migrate such runtime state based on declarative constraints defined by the language designer. We illustrate the approach using Nextep, a meta-modeling language for defining invariants and migration constraints on run-time state models. When a model changes, Nextep employs model finding techniques, backed by a solver, to automatically infer a new run-time model that satisfies the declared constraints. We apply Nextep to define migration strategies for two DSLs, and report on its expressiveness and performance

Revisiting visitors for modular extension of executable DSMLs

Executable Domain-Specific Modeling Languages (xDSMLs) are typically defined by metamodels that specify their abstract syntax, and model interpreters or compilers that define their execution semantics. To face the proliferation of xDSMLs in many domains, it is important to provide language engineering facilities for opportunistic reuse, extension, and customization of existing xDSMLs to ease the definition of new ones. Current approaches to language reuse either require to anticipate reuse, make use of advanced features that are not widely available in programming languages, or are not directly applicable to metamodel-based xDSMLs. In this paper, we propose a new language implementation pattern, named Revisitor, that enables independent extensibility of the syntax and semantics of metamodel-based xDSMLs with incremental compilation and without anticipation. We seamlessly implement our approach alongside the compilation chain of the Eclipse Modeling Framework, thereby demonstrating that it is directly and broadly applicable in various modeling environments. We show how it can be employed to incrementally extend both the syntax and semantics of the fUML language without requiring anticipation or re-compilation of existing code, and with acceptable performance penalty compared to classical handmade visitors

Breaking Bad? Semantic versioning and impact of breaking changes in Maven Central

ust like any software, libraries evolve to incorporate new features, bug fixes, security patches, and refactorings. However, when a library evolves, it may break the contract previously established with its clients by introducing Breaking Changes (BCs) in its API. These changes might trigger compile-time, link-time, or run-time errors in client code. As a result, clients may hesitate to upgrade their dependencies, raising security concerns and making future upgrades even more difficult.Understanding how libraries evolve helps client developers to know which changes to expect and where to expect them, and library developers to understand how they might impact their clients. In the most extensive study to date, Raemaekers et al. investigate to what extent developers of Java libraries hosted on the Maven Central Repository (MCR) follow semantic versioning conventions to signal the introduction of BCs and how these changes impact client projects. Their results suggest that BCs are widespread without regard for semantic versioning, with a significant impact on this http URL this paper, we conduct an external and differentiated replication study of their work. We identify and address some limitations of the original protocol and expand the analysis to a new corpus spanning seven more years of the MCR. We also present a novel static analysis tool for Java bytecode, Maracas, which provides us with: (i) the set of all BCs between two versions of a library; and (ii) the set of locations in client code impacted by individual BCs. Our key findings, derived from the analysis of 119, 879 library upgrades and 293, 817 clients, contrast with the original study and show that 83.4% of these upgrades do comply with semantic versioning. Furthermore, we observe that the tendency to comply with semantic versioning has significantly increased over time. Finally, we find that most BCs affect code that is not used by any client, and that only 7.9% of all clients are affected by BCs. These findings should help (i) library developers to understand and anticipate the impact of their changes; (ii) libra