diff --git a/src/testgen/core.clj b/src/testgen/core.clj
index ebd0357..dc442a6 100644
--- a/src/testgen/core.clj
+++ b/src/testgen/core.clj
@@ -5,5 +5,13 @@
      	(list 'is (list '= (list fnname arg) (eval (list fnname arg))))
 	(catch Exception e (list 'is (list 'thrown? (.getClass e) (list fnname arg))))))
 
-
 (defn testgen [fndef] nil)
+
+(defn is-constant? [x] (not (symbol? x)))
+
+(defn constants [form]
+  (filter is-constant? (flatten form)))
+
+(comment
+  (constants '(fn is-four [x] (= 88 [44])))
+  )