Generative and transformational techniques (GTT) have been around in the form of tools like Lex and Yacc for more than 30 years. These techniques are all about taking source- or model-level representation, and performing analysis, transformation, and potentially generating new sources or models.
Having now reached a level of maturity, GTT has become the "swiss army knife" of software development. More specifically GTT fills the need for programmable development tools that can deal with unique business or technical domain content. As such its use spreads from adding new features to mainstream languages, process sources in older languages or in new domain-specific languages (for which no compiler exists yet), to providing the glue to blend together sources and models defined at different levels, and effectively be a universal solution to model-driven development. What all these usages have in common is that they fulfill the need to have development systems and tools that work on making and managing transformations of source and models in a fully consistent manner.
To many developers, this is a new approach to software development because it gives up relying on a "single representation" for systems, such as source code. Instead, it focuses on describing systems with multiple representations and the transformations between these representations. For some industries, say game development, transformation-based methodology is now mainstream. Who would think of writing a game purely as source code? Instead, games are built from multiple inputs such as level layouts, character AI, physical and illumination models, then brought together with the help of proprietary and third-party tools.
Transformation-based approaches have not been mainstream because of the limited availability of off-the-shelf transformation tools (parser generators and compilers, for instance) and the difficulty of writing them. Now, new transformation tools are being introduced that are both powerful and flexible, making them real contenders as building blocks for any large development. These tools, their use, and some underlying theory were the subject of Generative and Transformational Techniques in Software Engineering (GTTSE2005).
Sessions covered many of the important usage trends of transformation technology, including:
- Domain-specific languages.
- Aspect-oriented programming.
- The use of features, reflection, modeling in case tools.
- The mapping and transformation of XML and databases systems.
- Source-to-source maintenance work.
It is worth mentioning that it is hard to do justice to the quality of the work that was presented at GTTSE2005. The executive committee Ralf Lämmel (Microsoft), and Joãco Saraiva Braga and Joost Visser (both of the Univeristy do Minho, Braga, Portugal) did an excellent job in leading the selection of presentations.