Dimitrios S. Kolovos

The Epsilon Transformation Language

Support for automated model transformation is essential for realizing a Model Driven Development (MDD) process. However, model transformation is only one of the many tools in a model engineering toolkit. To apply MDD in the large, automated support for a number of additional tasks such as model comparison, merging, validation and model-to-text transformation, is essential. While a number of successful model transformation languages have been currently proposed, the majority of them have been developed in isolation and as a result, they face consistency and integration difficulties with languages that support other model management tasks. We present the Epsilon Transformation Language (ETL), a hybrid model transformation language that has been developed atop the infrastructure provided by the Epsilon model management platform. By building atop Epsilon, ETL is seamlessly integrated with a number of other task-specific languages to help to realize composite model management workflows.

The epsilon object language (EOL)

Model-Driven Development requires model management languages and tools for supporting model operations such as editing, consistency checking, and transformation. At the core of these model management techniques is a set of facilities for model navigation and modification. A subset of the Object Constraint Language can be used for some of these tasks, but it has limitations as a general-purpose language to be used in a variety of model management tasks. We present the metamodel independent Epsilon Object Language (EOL) which builds on OCL. EOL can be used both as a standalone generic model management language or as infrastructure on which task-specific languages can be built. We describe how it has been used to construct a selection of languages, such as model merging, comparison, and text generation languages.

Different models for model matching: An analysis of approaches to support model differencing

Calculating differences between models is an important and challenging task in Model Driven Engineering. Model differencing involves a number of steps starting with identifying matching model elements, calculating and representing their differences, and finally visualizing them in an appropriate way. In this paper, we provide an overview of the fundamental steps involved in the model differencing process and summarize the advantages and shortcomings of existing approaches for identifying matching model elements. To assist potential users in selecting one of the existing methods for the problem at stake, we investigate the trade-offs these methods impose in terms of accuracy and effort required to implement each one of them.

Model migration with epsilon flock

In their recent book, Mens and Demeyer state that Model-Driven Engineering introduces additional challenges for controlling and managing software evolution. Today, tools exist for generating model editors and for managing models with transformation, validation, merging and weaving. There is limited support, however, for model migration - a development activity in which instance models are updated in response to metamodel evolution. In this paper, we describe Epsilon Flock, a model-to-model transformation language tailored for model migration that contributes a novel algorithm for relating source and target model elements. To demonstrate its conciseness, we compare Flock to other approaches.

Model comparison: a foundation for model composition and model transformation testing

In the context of Model Driven Development, Model Transformation and Model Composition are two essential model management tasks. In this paper, we demonstrate how both tasks can benefit, in different ways, from the automation of another fundamental task: Model Comparison. We derive requirements for a model comparison solution incrementally, and demonstrate a concrete rule-based model comparison approach we have developed in the context of a generic model merging language.

The Epsilon Generation Language

We present the Epsilon Generation Language (EGL), a model-to-text (M2T) transformation language that is a component in a model management tool chain. The distinctive features of EGL are described, in particular its novel design which inherits a number of language concepts and logical features from a base model navigation and modification language. The value of being able to use a M2T language as part of an extensible model management tool chain is outlined in a case study, and EGL is compared to other M2T languages.

A canonical scheme for model composition

There is little agreement on terminology in model composition, and even less on key characteristics of a model composition solution. We present three composition frameworks: the Atlas Model Weaver, the Epsilon Merging Language, and the Glue Generator Tool, and from them derive a core set of common definitions. We use this to outline the key requirements of a model composition solution, in terms of language and tool support.

A research roadmap towards achieving scalability in model driven engineering

As Model-Driven Engineering (MDE) is increasingly applied to larger and more complex systems, the current generation of modelling and model management technologies are being pushed to their limits in terms of capacity and efficiency. Additional research and development is imperative in order to enable MDE to remain relevant with industrial practice and to continue delivering its widely recognised productivity, quality, and maintainability benefits. Achieving scalability in modelling and MDE involves being able to construct large models and domain-specific languages in a systematic manner, enabling teams of modellers to construct and refine large models in a collaborative manner, advancing the state of the art in model querying and transformations tools so that they can cope with large models (of the scale of millions of model elements), and providing an infrastructure for efficient storage, indexing and retrieval of large models. This paper attempts to provide a research roadmap for these aspects of scalability in MDE and outline directions for work in this emerging research area.

On the evolution of OCL for capturing structural constraints in modelling languages

The Object Constraint Language (OCL) can be used to capture structural constraints in the context of the abstract syntax of modelling languages (metamodels) defined in the MOF metamodelling architecture. While the expression language of OCL has been revised and updated a number of times since its inception, the constructs used for capturing constraints (invariants) have remained unchanged. In this paper we argue that the abstract and concrete syntax of OCL invariants should also be updated to address a number of shortcomings and render OCL more usable in a contemporary modelling environment. To support our arguments we have implemented the proposed extensions in the prototype Epsilon Validation Language (EVL). To demonstrate the benefits delivered, we present and discuss a concrete example.

Taming EMF and GMF using model transformation

EMF and GMF are powerful frameworks for implementing tool support for modelling languages in Eclipse. However, with power comes complexity; implementing a graphical editor for a modelling language using EMF and GMF requires developers to hand craft and maintain several low-level interconnected models through a loosely-guided, labour-intensive and error-prone process. In this paper we demonstrate how the application of model transformation techniques can help with taming the complexity of GMF and EMF and deliver significant productivity, quality, and maintainability benefits. We also present EuGENia, an open-source tool that implements the proposed approach, illustrate its functionality through an example, and report on the communitys response to the tool.