--- a/record.ur	Thu Feb 03 09:31:32 2011 -0500
+++ b/record.ur	Thu Feb 03 14:22:02 2011 -0500
@@ -1,3 +1,6 @@
+fun numFields [r ::: {Type}] (fl : folder r) (r : $r) : int =
+    @fold [fn _ => int] (fn [nm ::_] [u ::_] [r ::_] [[nm] ~ r] acc => acc+1) 0 fl
+
 fun mem [a ::: Type] [ns ::: {Unit}] (_ : eq a) (fl : folder ns) (x : a) (r : $(mapU a ns)) : bool =
     @foldUR [a] [fn _ => bool]
      (fn [nm ::_] [r ::_] [[nm] ~ r] y acc =>