[ANN] constraint-0.2

Alexandre Alexandre.Fayolle at logilab.fr
Fri Jun 7 12:50:52 EDT 2002

Logilab has released constraint-0.2.

The constraint package is an extensible Constraint Satisfaction Problem
(CSP) solver using constraint propagation algorithms written in 100%
pure Python (tested with Python 2.1)

You can download it from ftp://ftp.logilab.org/pub/constraint/, read a
bit more about it on
and discuss it on the logic-sig mailing list (see
http://lists.logilab.org/mailman/listinfo/python-logic to subscribe)

The package is still young, but we find it useful enough right now, so I
thought I might as well publish it.

What can it do?
 * solve some finite-domain CSP
 * handle n-ary constraints

How can you extend it:
 * by implementing new Domain classes
 * by implementing new constraint classes
 * by implementing new Distributor classes

How well does it perform?
 * 8-queens problems solved in 15 seconds on my 1GHz PC
 * SEND+MORE=MONEY problem solved in 8 seconds on the same machine

What has changed?
 * a BasicConstraint class was added (these constraint affect only a single
 variable, and can be entailed in one pass), with several example
 * The Repository class was refactored, and a Solver class was added as
 a result, which gives a better separation of the solving logic and
 storage logic

If you're interested by constraint propagation programming in python,
please join the logic-sig mailing list.
Alexandre Fayolle
LOGILAB, Paris (France).
http://www.logilab.com   http://www.logilab.fr  http://www.logilab.org
Narval, the first software agent available as free software (GPL).

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