The next Comète seminar will take place next Tuesday 18th of October at 14h00 in Salle Philippe Flajolet (LIX). Prof. Moreno Falaschi, researcher at University of Siena, Italy, will talk about “Slicing Concurrent Constraint Programs”.

Abstract: Concurrent Constraint Programming (ccp) is a declarative model for concurrency where agents interact by telling and asking constraints (pieces of information) in a shared store. Some previous works have developed (approximated) declarative debuggers for CCP languages. However, the task of debugging concurrent programs remains difficult. In this paper we define a dynamic slicer for ccp and we show it to be a useful companion tool for the existing debugging techniques. Our technique starts by considering a partial computation (a trace) that shows the presence of bugs. Often, the quantity of information in such a trace is overwhelming, and the user gets easily lost, since she cannot focus on the sources of the bugs. Our slicer allows for marking part of the state of the computation and assists the user to eliminate most of the redundant information in order to highlight the errors. We show that this technique can be tailored to timed variants of CCP. We also developed a prototypical implementation freely available for making experiments.