Improving Prolog Programs: Refactoring for Prolog

Refactoring is an established technique from the OO-community to restructure code: it aims at improving software readability, maintainability and extensibility. Although refactoring is not tied to the OO-paradigm in particular, its ideas have not been applied to Logic Programming until now. This paper applies the ideas of refactoring to Prolog programs. A catalogue is presented listing refactorings classified according to scope. Some of the refactorings have been adapted from the OO-paradigm, while others have been specifically designed for Prolog. Also the discrepancy between intended and operational semantics in Prolog is addressed by some of the refactorings. In addition, ViPReSS, a semi-automatic refactoring browser, is discussed and the experience with applying \vipress to a large Prolog legacy system is reported. Our main conclusion is that refactoring is not only a viable technique in Prolog but also a rather desirable one.Comment: To appear in ICLP 200

Proceedings of the 1st workshop on aspect reverse-engineering, Delft, 09.11.2004

This technical report contains the papers submitted to and presented at the 1st Workshop on Aspect Reverse-Engineering, held in conjunction with the 11th Working Conference on Reverse Engineering (WCRE), in Delft, The Netherlands. The aims of this workshop was to bring together researchers and practitioners within the field of aspect reverse engineering, to review the state-of-the-art and state-of-the-practice and to identify a list of interesting open issues that remain to be studied. The workshop was organised as a structured discussion, based on interesting and relevant topics extracted from position paper

Angiotensin IV displays only low affinity for native insulin-regulated aminopeptidase (IRAP).

&lt;p&gt;Radioligand binding studies revealed that Ang IV binds to insulin-regulated aminopeptidase (IRAP)/&amp;#39;AT(4) receptors&amp;#39; with high affinity. Yet, as these experiments were routinely carried out in the presence of chelators, only the catalytic zinc-depleted apo-form of IRAP was labelled. While the chelators remove the catalytic zinc from IRAP and protect Ang IV from proteolytic degradation, the aminopeptidase N selective inhibitor &amp;#39;7B&amp;#39; only exerts the latter effect. By using 7B along with the new stable Ang IV-analog [(3) H]AL-11, we here show that the native enzyme is only a low-affinity target for Ang IV.&lt;/p&gt;</p

Simple Crosscutting Concerns Are Not So Simple: Analysing Variability in Large-Scale Idioms-Based Implementations

This paper describes a method for studying idioms-based implementations of crosscutting concerns, and our experiences with it in the context of a real-world, large-scale embedded software system. In particular, we analyse a seemingly simple concern, tracing, and show that it exhibits significant variability, despite the use of a prescribed idiom. We discuss the consequences of this variability in terms of how aspect-oriented software development techniques could help prevent it, how it paralyses (automated) migration efforts, and which aspect language features are required in order to obtain precise and concise aspects. Additionally, we elaborate on the representativeness of our results and on the usefulness of our proposed method. Preprint accepted for publication in: Sixth International Conference on Aspect-Oriented Software Development, Vancouver, Canada, March 12-16, 2007Software TechnologyElectrical Engineering, Mathematics and Computer Scienc