diff type profiling cells pycket

gistfile1.txt

diff --git a/pycket/values.py b/pycket/values.py
index ef11567..a2ca9de 100755
--- a/pycket/values.py
+++ b/pycket/values.py
@@ -42,12 +42,24 @@ class W_Object(object):
     def eqv(self, other):
         return self is other # default implementation
 
+from collections import defaultdict
+celltypes = defaultdict(int)
+settypes = defaultdict(int)
+
+import atexit
+def printall():
+    print "at construction", celltypes
+    print "when set", settypes
+atexit.register(printall)
+
 class W_Cell(W_Object): # not the same as Racket's box
     def __init__(self, v):
+        celltypes[type(v)] += 1
         assert not isinstance(v, W_Cell)
         self.value = v
 
     def set_val(self, w_value):
+        settypes[type(w_value)] += 1
         self.value = w_value
 
 class W_MVector(W_Object):