gfredericks · December 19, 2012 04:00 · Dec 19, 2012
diff --git a/condr.clj b/condr.clj
@@ -0,0 +1,23 @@
+(defn condr*
+  [& goals]
+  (if (= 1 (count goals))
+    (first goals)
+    (let [goals (shuffle goals)]
+      (conde
+       [(first goals)]
+       [(apply condr* (rest goals))]))))
+
+(defmacro condr
+  "Same as conde but clauses are scrambled on each call."
+  [& clauses]
+  `(condr* ~@(for [clause clauses] (cons `all clause))))
+
+
+;; example usage
+
+(defn listso
+  [x]
+  (condr
+   [(membero x [:a :b :c])]
+   [(== [] x)]
+   [(fresh [a b] (listso a) (listso b) (== [a b] x))]))