A Language Description is More than a Metamodel

Within the context of (software) language engineering, language descriptions are considered first class citizens. One of the ways to describe languages is by means of a metamodel, which represents the abstract syntax of the language. Unfortunately, in this process many language engineers forget the fact that a language also needs a concrete syntax and a semantics. In this paper I argue that neither of these can be discarded from a language description. In a good language description the abstract syntax is the central element, which functions as pivot between concrete syntax and semantics. Furthermore, both concrete syntax and semantics should be described in a well-defined formalism

Building a Flexible Software Factory Using Partial Domain Specific Models

This paper describes some experiences in building a software factory by defining multiple small domain specific languages (DSLs) and having multiple small models per DSL. This is in high contrast with traditional approaches using monolithic models, e.g. written in UML. In our approach, models behave like source code to a large extend, leading to an easy way to manage the model(s) of large systems

Engineering Object-Oriented Semantics Using Graph Transformations

In this paper we describe the application of the theory of graph transformations to the practise of language design. We have defined the semantics of a small but realistic object-oriented language (called TAAL) by mapping the language constructs to graphs and their operational semantics to graph transformation rules. In the process we establish a mapping between UML models and graphs. TAAL was developed for the purpose of this paper, as an extensive case study in engineering object-oriented language semantics using graph transformation. It incorporates the basic aspects of many commonly used object-oriented programming languages: apart from essential imperative programming constructs, it includes inheritance, object creation and method overriding. The language specification is based on a number of meta-models written in UML. Both the static and dynamic semantics are defined using graph rewriting rules. In the course of the case study, we have built an Eclipse plug-in that automatically transforms arbitrary TAAL programs into graphs, in a graph format readable by another tool. This second tool is called Groove, and it is able to execute graph transformations. By combining both tools we are able to visually simulate the execution of any TAAL program

Composing Transformation Operations Based on Complex Source Pattern Definitions

Rule composition and decomposition is a hot research topic within the context of model transformation. Mostly, transformation rules are considered as atomic parts of the transformation and rule composition has been the focus of recent research in the model transformation area. In our approach, we consider the transformation operations such as add, delete and update operations as the atomic parts of the transformation and the synthesis of these operations constitutes a single transformation rule. Defining complex and hierarchical source pattern definitions requires approaches and techniques about the composition and decomposition of these operations. In this paper, we discuss the problem statement and present an example case in which operation composition is required

Towards the Generation of a Text-Based IDE from a Language Metamodel

In the model driven world languages are usually specified by a (meta) model of their abstract syntax. For textual languages this is different from the traditional approach, where the language is specified by a (E)BNF grammar. Support for the designer of textual languages, e.g. a parser generator, is therefore normally based on grammars. This paper shows that similar support for language design based on metamodels is not only possible, but is even more powerful than the support based on grammars. In this paper we describe how an integrated development environment for a language can be generated from the language’s abstract syntax metamodel, thus providing the language designer with the possibility to quickly, and with little effort, create not only a new language but also the tooling necessary for using this language

From UML Activities to TAAL: Towards behaviour-preserving model transformations

Model transformations support a model-driven design by providing an automatic translation of abstract models into more concrete ones, and eventually program code. Crucial to a successful application of model transformations is their correctness, in the sense that the meaning (semantics) of the models is preserved. This is especially important if the models not only describe the structure but also the intended behaviour of the systems. Reasoning about and showing correctness is, however, often impossible as the source and target models typically lack a precise definition of their semantics. In this paper, we take a first step towards provably correct behavioural model transformations. In particular, we develop transformations from UML Activities (which are visual models) to programs in TAAL, which is a textual Java-like programming language. Both languages come equipped with formal behavioural semantics, which, moreover, have the same semantic domain. This sets the stage for showing correctness, which in this case comes down to showing that the behaviour of every (well-formed) UML Activity coincides with that of the corresponding TAAL program, in a well-defined sense