[cl-unification-cvs] CVS update: cl-unification/unifier.lisp

[Marco Antoniotti]

Update of /project/cl-unification/cvsroot/cl-unification
In directory common-lisp.net:/tmp/cvs-serv20210

Modified Files:
	unifier.lisp 
Log Message:
Fixed two major bugs reported by Norman Werver.  Unification of
strings and symbols and of numers and symbols was not recurring on
VAR-UNIFY, as required; thus

	(unify '(?x ?x) '("asd" "qweert"))
and
	(unify '(foo ?x baz) '(foo 42 ?x))

would succed.
The two cases are now fixed.

Date: Fri May 20 17:19:53 2005
Author: mantoniotti

Index: cl-unification/unifier.lisp
diff -u cl-unification/unifier.lisp:1.2 cl-unification/unifier.lisp:1.3
--- cl-unification/unifier.lisp:1.2	Fri Jan 28 20:30:35 2005
+++ cl-unification/unifier.lisp	Fri May 20 17:19:53 2005
@@ -94,15 +94,15 @@
 
 (defmethod unify ((a symbol) (b string) &optional (env (make-empty-environment)))
   (cond ((variable-any-p a) env)
-        ((variablep a) (extend-environment a b env))
+        ((variablep a) (var-unify a b env))
         (t (error 'unification-failure
-             :format-control "Cannot unify a symbol with a string: ~S ~S."
-             :format-arguments (list a b)))))
+		  :format-control "Cannot unify a symbol with a string: ~S ~S."
+		  :format-arguments (list a b)))))
 
 
 (defmethod unify ((b string) (a symbol) &optional (env (make-empty-environment)))
   (cond ((variable-any-p a) env)
-        ((variablep a) (extend-environment a b env))
+        ((variablep a) (var-unify a b env))
         (t (error 'unification-failure
                   :format-control "Cannot unify a string with a symbol: ~S ~S."
                   :format-arguments (list b a)))))
@@ -121,13 +121,13 @@
 
 (defmethod unify ((a symbol) (b t) &optional (env (make-empty-environment)))
   (cond ((variable-any-p a) env)
-        ((variablep a) (extend-environment a b env))
+        ((variablep a) (var-unify a b env))
         (t (call-next-method))))
 
 
 (defmethod unify ((b t) (a symbol) &optional (env (make-empty-environment)))
   (cond ((variable-any-p a) env)
-        ((variablep a) (extend-environment a b env))
+        ((variablep a) (var-unify a b env))
         (t (call-next-method))))