3 research outputs found
Value Withdrawal Explanation in CSP
This work is devoted to constraint solving motivated by the debugging of
constraint logic programs a la GNU-Prolog. The paper focuses only on the
constraints. In this framework, constraint solving amounts to domain reduction.
A computation is formalized by a chaotic iteration. The computed result is
described as a closure. This model is well suited to the design of debugging
notions and tools, for example failure explanations or error diagnosis. In this
paper we detail an application of the model to an explanation of a value
withdrawal in a domain. Some other works have already shown the interest of
such a notion of explanation not only for failure analysis.Comment: In M. Ducasse (ed), proceedings of the Fourth International Workshop
on Automated Debugging (AADEBUG 2000), August 2000, Munich. cs.SE/001003
Rigorous design of tracers: an experiment for constraint logic programming
In order to design and implement tracers, one must decide what exactly to
trace and how to produce this trace. On the one hand, trace designs are too
often guided by implementation concerns and are not as useful as they should
be. On the other hand, an interesting trace which cannot be produced
efficiently, is not very useful either. In this article we propose a
methodology which helps to efficiently produce accurate traces. Firstly, design
a formal specification of the trace model. Secondly, derive a prototype tracer
from this specification. Thirdly, analyze the produced traces. Fourthly,
implement an efficient tracer. Lastly, compare the traces of the two tracers.
At each step, problems can be found. In that case one has to iterate the
process. We have successfully applied the proposed methodology to the design
and implementation of a real tracer for constraint logic programming which is
able to efficiently generate information required to build interesting
graphical views of executions.Comment: In M. Ronsse, K. De Bosschere (eds), proceedings of the Fifth
International Workshop on Automated Debugging (AADEBUG 2003), September 2003,
Ghent. cs.SE/030902
Prototyping CLP(FD) Tracers: a Trace Model and an Experimental Validation Environment
Developing and maintaining CLP programs requires visualization and
explanation tools. However, existing tools are built in an ad hoc way.
Therefore porting tools from one platform to another is very difficult. We have
shown in previous work that, from a fine-grained execution trace, a number of
interesting views about logic program executions could be generated by trace
analysis.
In this article, we propose a trace model for constraint solving by
narrowing. This trace model is the first one proposed for CLP(FD) and does not
pretend to be the ultimate one. We also propose an instrumented
meta-interpreter in order to experiment with the model. Furthermore, we show
that the proposed trace model contains the necessary information to build known
and useful execution views. This work sets the basis for generic execution
analysis of CLP(FD) programs.Comment: In A. Kusalik (ed), Proceedings of the Eleventh International
Workshop on Logic Programming Environments (WLPE'01), December 1, 2001,
Paphos, Cyprus. cs.PL/011104