LOGIC-46: Unification on Struct Maps Causes Error

clojure · Oct 5, 2012 · a62e7f1 · a62e7f1
1 parent 9793085
commit a62e7f1
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Showing 2 changed files with 19 additions and 8 deletions.
diff --git a/src/main/clojure/clojure/core/logic.clj b/src/main/clojure/clojure/core/logic.clj
@@ -1502,21 +1502,17 @@
 
   clojure.lang.IPersistentMap
   (unify-with-map [v u s]
-    ;; TODO: the key count of v & u must be the same
+    (when (= (count u) (count v))
-    (let [ks (keys u)]
+      (loop [ks (keys u) s s]
-      (loop [ks ks u u v v s s]
         (if (seq ks)
           (let [kf (first ks)
                 vf (get v kf ::not-found)]
             (if (= vf ::not-found)
               nil
               (if-let [s (unify s (get u kf) vf)]
-                ;; TODO: there's no need to dissoc the keys - breaks struct maps
+                (recur (next ks) s)
-                (recur (next ks) (dissoc u kf) (dissoc v kf) s)
                 nil)))
-          (if (seq v)
+          s)))))
-            nil
-            s))))))
 
 ;; -----------------------------------------------------------------------------
 ;; Unify Refinable with X

diff --git a/src/test/clojure/clojure/core/logic/tests.clj b/src/test/clojure/clojure/core/logic/tests.clj
@@ -352,6 +352,21 @@
         m2 {1 4 3 x}]
     (is (= (unify empty-s m1 m2) nil))))
 
+(defstruct foo-struct :a :b)
+
+(deftest unify-struct-map-1
+  (let [x (lvar 'x)
+        m1 (struct-map foo-struct :a 1 :b 2)
+        m2 (struct-map foo-struct :a 1 :b x)
+        os (ext-no-check empty-s x 2)]
+    (is (= (unify empty-s m1 m2) os))))
+
+(deftest unify-struct-map-2
+  (let [x (lvar 'x)
+        m1 (struct-map foo-struct :a 1 :b 2)
+        m2 (struct-map foo-struct :a 1 :b 3)]
+    (is (= (unify empty-s m1 m2) nil))))
+
 ;; =============================================================================
 ;; walk