School of Computing

A Backward Analysis for Constraint Logic Programs

A. King and L. Lu

Technical Report 4-01, University of Kent, Computing Laboratory, University of Kent at Canterbury, Kent, CT2 7NF, UK, December 2001 To appear in Theory and Practice of Logic Programming.

Abstract

One recurring problem in program development is that of understanding how to re-use code developed by a third party. In the context of (constraint) logic programming, part of this problem reduces to figuring out how to query a program. If the logic program does not come with any documentation, then the programmer is forced to either experiment with queries in an \textit{ad hoc} fashion or trace the control-flow of the program (backward) to infer the modes in which a predicate must be called so as to avoid an instantiation error. This paper presents an abstract interpretation scheme that automates the latter technique. The analysis presented in this paper can infer moding properties which if satisfied by the initial query, come with the guarantee that the program and query can never generate any moding or instantiation errors. Other applications of the analysis are discussed. The paper explains how abstract domains with certain computational properties (they condense) can be used to trace control-flow backward (right-to-left) to infer useful properties of initial queries. A correctness argument is presented and an implementation is reported.

Download publication 549 kbytes (PostScript)

Bibtex Record

@techreport{1201,
author = {A. King and L. Lu},
title = {{A Backward Analysis for Constraint Logic Programs}},
month = {December},
year = {2001},
pages = {182-196},
keywords = {determinacy analysis, Craig interpolants},
note = {To appear in Theory and Practice of Logic Programming},
doi = {},
url = {http://www.cs.kent.ac.uk/pubs/2001/1201},
    publication_type = {techreport},
    submission_id = {17038_989827719},
    number = {4-01},
    address = {University of Kent at Canterbury, Kent, CT2 7NF, UK},
    institution = {University of Kent, Computing Laboratory},
}

School of Computing, University of Kent, Canterbury, Kent, CT2 7NF

Enquiries: +44 (0)1227 824180 or contact us.

Last Updated: 21/03/2014