Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!munnari.oz.au!bruce!alanf
From: alanf@bruce.OZ (Alan Grant Finlay)
Newsgroups: comp.lang.icon
Subject: Re: icon & prolog
Summary: I wrote such a beast
Message-ID: <1996@bruce.OZ>
Date: 29 Mar 90 10:54:12 GMT
References: <9003281833.AA18812@sophist.uchicago.edu>
Distribution: inet
Organization: Monash Uni. Computer Science, Australia
Lines: 25

In article <9003281833.AA18812@sophist.uchicago.edu>, goer@SOPHIST.UCHICAGO.EDU (Richard Goerwitz) writes:
> Just an idle question:  Has anyone thought of implementing
> Prolog in Icon, either as a Prolog -> Icon translator, or
> as a Prolog interpreter written in Icon?  I'm not a Prolog ...

I wrote a Prolog interpreter in Icon some time ago.  I never got
around to doing anything with it (i.e. publishing wise).  I was
in the process of writing the converse (Icon interpreter in Prolog)
when I got sidetracked.  I will post the sources and documentation.
There were four versions in increasing order of complexity.  I only got
around to documentation for versions 1 and 2.  The versions appear to
have implemented the following incrementally:
	1. Basic pure Prolog with negation by failure,
	2. List notation added (syntactic sugar),
	3. Assert and Retract,
	4. Cut.

The program documentation files *.doc are in troff format.  They're still
readable however.  The user guides *.usr are just plain text.  The source
is copyright in the sense that it can be used anywhere for any purpose 
provided the copyright is maintained and I get credit for my work.

I would be interested in any comments about the code.  I was trying to get
as succinct a source file as possible without sacrificing clarity (but its
always tempting to save a line here and there!).