Towards a Generic Trace for Rule Based Constraint Reasoning

CHR is a very versatile programming language that allows programmers to declaratively specify constraint solvers. An important part of the development of such solvers is in their testing and debugging phases. Current CHR implementations support those phases by offering tracing facilities with limited information.In this paper, we propose a new trace for CHR which contains enough information to analyze any aspects of CHR∨ execution at some general abstract level.This approach is based on the idea of generic trace. Such a trace is formally defined as an extension of the ω∨ r semantics. It is currently prototyped in a SWI Prolog based CHR implementation.