A simple implementation of a subset of prolog, a logic programming language, in Clojure.
This is heavily based on the prolog in lisp implementation by Peter Norvig in Paradigms of AI Programming: Case Studies in Common Lisp
If you actually want to write logic programs in Clojure, please use the logic programming features for Clojure in core.logic
Note: This is still very much under development, as I am using this as a way of learning clojure by writing more code.
Creation of rules & facts:
(<- (likes Kim Robin))
(<- (likes Sandy Lee))
(<- (likes Sandy Kim))
(<- (likes Robin cats))
(<- (likes Sandy ?x) (likes ?x cats))
(<- (likes Kim ?x) (likes ?x Lee) (likes ?x Kim))
(<- (likes ?x ?x))Basic interaction:
user> (use :reload 'clj-prolog.core)
nil
user> (?- (likes Sandy ?who))
?who = Sandy;
?who = cats;
?who = Sandy;
?who = Robin;
?who = Kim;
?who = Lee;
nil
user> (?- (likes ?who Sandy))
?who = Sandy;
?who = Kim;
?who = Sandy;
nil
user> (?- (likes Robin Lee))
No.
nilUnification:
user> (use :reload 'clj-prolog.unify)
nil
user> (unify '(?x + 1) '(2 + ?y))
((?y 1) (?x 2))Copyright (C) 2011 Geoff Wilson
Distributed under the Eclipse Public License, the same as Clojure.