Plenary Lecture

Visualizing Programs

Professor Harald Wertz
Department of Computer Science
Laboratoire d' Informatique Avancee de Saint- Denis (LIASD)
2, Rue de la Liberte
93526 Saint-Denis Cedex, France
E-mail: hw@ai.univ-paris8.fr

Abstract: During their live cycle, programs have a tendency to grow and, by the way, to increase their complexity, thus becoming harder and harder to read, to understand and to maintain. But understanding programs is necessary for their continuous evolution, their maintenance and debugging.
Various tools, such as metrics, abstract interpretation, model checking, code coverage, program slicing, data-flow analysis, pointer analysis, call graphs, data-flow graphs and dependency graphs (to name but a few), have been developed to help programmers in their understanding of the structure and functioning of programs. In this lecture we will present various ways of displaying graphs and focus on the impact of visualization of such static and dynamic data dependencies in the context of program maintenance. We will examine several prototypes we have developed in our laboratory, detailing especially the different visualizations we propose, which are aimed to minimize the conceptual overload in order to allow users to deal with hard to understand or buggy programs.

Brief Biography of the Speaker:
Harald Wertz was born in 1947 in Friedrichshafen, Germany, and is living in France since 1971. He is Professor of Computer Science at the Universite Paris 8, France, since 1978, and he is a founding member of the Franco-Georgian Institute. He loves to teach introductory programming classes, artificial intelligence and software engineering. His research focuses mainly on the intersection between artificial intelligence and software engineering: finding computational methods helping to understand, debug and meaningfully represent programs. His doctoral thesis, at the University of Paris 6, described a Lisp-system able to automatically debug programs written by novice programmers. His ‘these d’etat es science’, at the Universite de Vincennes, described the structure, implementation and use of an integrated and incremental programming environment, which included (then) novel features such as automatic documentation, automatic construction of outstanding task lists, on the fly correction, reverse execution and executable program annotation. He is the author of three books, several book chapters and some seventy papers.