Prolog-style unification?

junk junk at geekabytes.net
Sat Jun 7 22:38:40 CEST 2003


Robert Oschler wrote:

>Has anybody seen a Python module that adds Prolog-style unification (pattern
>matching) to Python?  I know about PyLog and SnoPy, but that's not quite
>what I'm looking for.
>
>thx
>
>--
>Robert Oschler,
>Android Technologies, Inc.
>http://www.androidtechnologies.com
>- The home of Off-Book! (tm)
>The scene memorization tool for Actors and Actresses!
>
>
>  
>
Hi Robert,

I am working on a Master's Thesis currently where this issue is of 
concern.  I would also like to know if there is such a module.

In the mean time, I have written my own module which does a pretty good 
job of simulating Prolog style calls.  Here is what my syntax looks like 
right now:

import logic
Father = logic.Fact()
Father("Seth","Alex")
Father("James","Seth")
X = logic.LogicalVariable()
Y = logic.LgocialVariable()
while Father(X,Y):
    print X, Y

print "--------------"

Grandfather = logic.Fact()
Grandfather(Grandfather.Grandfather, Grandfather.Grandson) (
    Father(Grandfather.Grandfather, Grandfather.Son)
    Father(Grandfather.Son, Grandfather.Grandson))

while Grandfather(X,Y):
    print X,Y


The output of this is:

James Seth
Seth Alex
------------------
James Alex

I'm still tracking down bugs all the time, but it's getting pretty good.

Would you PLEASE let me know what you think?

-- Seth James Nielson






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