intbv and Signal unhashable

myhdl/Signal.py

@@ -132,6 +132,10 @@ class Signal(object):
     negedge = property(_get_negedge, None, None, "'posedge' access methodes")
     
 
+    # hashing not supported
+    def __hash__(self):
+        assert TypeError, "Signal objects are unhashable"
+        
     ### operators for which delegation to current value is appropriate ###
     
     def __nonzero__(self):

myhdl/Signal_spec.txt

@@ -102,3 +102,5 @@ In the following, a "sig" denotes an instance of the Signal class.
 * A sig should have no other public attributes than those described
   above.
 
+* Signal objects are unhashable.
+

myhdl/intbv.py

@@ -69,6 +69,9 @@ class intbv(object):
             res._len = basewidth + width
         return res
 
+    # hash
+    def __hash__(self):
+        raise TypeError, "intbv objects are unhashable"
         
     # copy methods
     def __copy__(self):

myhdl/intbv_spec.txt

@@ -77,6 +77,7 @@ separate type.
   addition, literal bit strings are accepted in concatenations, just as
   they are in intbv constructors.
 
-
 * intbv supports the iterator protocol to iterate on its bits; again,
   this requires a known length.
+
+* intbv objects are unhashable

myhdl/test_Signal.py

@@ -30,6 +30,11 @@ from Signal import Signal
 from _simulator import _siglist
 from intbv import intbv
 
+class TestSignalUnhashable(TestCase):
+
+    def testSignalUnhashable(self):
+        self.assertRaises(TypeError, hash, Signal(3))
+        
 class SigTest(TestCase):
 
     def setUp(self):

myhdl/test_intbv.py

@@ -35,6 +35,10 @@ import operator
 from intbv import intbv
 concat = intbv.concat
 
+class TestIntbvUnhashable(TestCase):
+
+    def testIntbvUnhashable(self):
+        self.assertRaises(TypeError, hash, intbv(3))
 
 
 class TestIntbvConcat(TestCase):