On 20 Nov 2003, at 09:50, Jean Jordaan wrote:


<excerpt>Hi all


I saw drobbins's mention of Prolog as a possibility for future

portage, because of the need for logic programming. As a Python

lover, I have to point at the Logilab.org - Python Logic SIG,

implementing logic programming in Python.

  http://www.logilab.org/projects/python-logic

</excerpt>

Hi,


I'm writing portage core in (iso-compliant) prolog as part of my
thesis at the free university of brussels, I'll make my papers with
implementation available to gentoo. 

I'm not familiar with the libraries you suggested, but Pylog seems
very interesting, because at first sight it is able to interpret
iso-compliant prolog. However I saw the following warning:

<fontfamily><param>Arial</param>

WARNING: The cut doesn't work well in the current PyLog version
(backtracking over a cut doesn't undo the unifications done before the
cut). This problem seems hard to fix with the current structure of
PyLog and won't be tackled soon. 

</fontfamily>

since cut is a rather crucial part of prolog, (and surely affects
performance), I doubt that Pylog implements enough of the iso standard
(efficiently?) to run a real prolog program. Same goes for the
constraints package, which seems to provide only limited support. We
also need to investigate whether bugs are fixed rappidly enough...  


I was under the impression that prolog has very few dependencies and
is able to interact with most languages (including python), so I guess
the need to really include it in python or some other language is
rather low, but I'm not excluding anything :-) 


Regards,


Pieter


<excerpt>From the site:


"""

The goal of the "unofficial" Logic-SIG is to provide logic programming
and constraint-propagation features in Python. If you are interested
in participating, please join the mailing list.


1. Available software


    * Logilab's constraint package is a full-python constraint
satisfaction solver similar that what Oz/Mozart implements.

    * PyLog from Christophe Delord is a first order logic library in
Python

"""


-- 

Jean Jordaan

http://www.upfrontsystems.co.za



--

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</excerpt>