Added first take at enum type

myhdl/__init__.py

@@ -57,5 +57,6 @@ from util import downrange, Error, StopSimulation
 from bin import bin
 from misc import instances, processes
 from always_comb import always_comb
+from enum import enum
 from trace_sigs import trace_sigs
 

myhdl/enum.py

@@ -0,0 +1,48 @@
+from types import StringType
+
+
+def enum(*args):
+
+    args = list(args)
+    # only default encoding for now
+    argdict = {}
+    encoding = {}
+    i = 0
+    for arg in args:
+        if type(arg) is not StringType:
+            raise TypeError
+        if argdict.has_key(arg):
+            raise ValueError
+        argdict[i] = arg
+        encoding[arg] = i
+        i += 1
+        
+    class EnumItem(object):
+        def __init__(self, arg):
+            self._val = encoding[arg]
+        def __repr__(self):
+            return argdict[self._val]
+        __str__ = __repr__
+
+    class Enum(object):
+        def __init__(self):
+            for slot in args:
+                self.__dict__[slot] = EnumItem(slot)
+        def __setattr__(self, attr, val):
+            raise AttributeError
+        def __len__(self):
+            return len(args)
+        def __repr__(self):
+            s = ""
+            for arg in args:
+                s += "%s=%d, " % (arg, encoding[arg])
+            return "<Enum: %s>" % s[:-2]
+        __str__ = __repr__
+        
+    return Enum()
+
+
+
+
+    
+