--- a/python/pyyacc.py	Sat May 25 15:15:42 2013 +0200
+++ b/python/pyyacc.py	Sun May 26 15:28:07 2013 +0200
@@ -2,6 +2,8 @@
   Parser generator script
 """
 
+from ppci import Token
+
 EPS = 'EPS'
 EOF = 'EOF'
 SHIFT = 1
@@ -272,15 +274,17 @@
         self.goto_table = goto_table
 
     def parse(self, toks):
+        """ Parse an iterable with tokens """
+        assert hasattr(toks, '__iter__'), '{0} not iter type'.format(type(toks))
         stack = [0]
-        look_ahead = toks.pop(0)
+        look_ahead = toks.__next__()
+        assert type(look_ahead) is Token
         while True:
             state = stack[-1]   # top of stack
-            key = (state, look_ahead)
+            key = (state, look_ahead.typ)
             if not key in self.action_table:
-                print(key)
-                raise Exception('Error parsing')
-            action, param = self.action_table[(state, look_ahead)]
+                raise Exception('Error parsing at character {0}'.format(look_ahead))
+            action, param = self.action_table[key]
             if action == REDUCE:
                 for s in param.symbols:
                     stack.pop()
@@ -289,9 +293,13 @@
                 stack.append(param.name)
                 stack.append(self.goto_table[(state, param.name)])
             elif action == SHIFT:
-                stack.append(look_ahead)
+                stack.append(look_ahead.typ)
                 stack.append(param)
-                look_ahead = toks.pop(0)
+                try:
+                    look_ahead = toks.__next__()
+                except StopIteration:
+                    look_ahead = Token(EOF, EOF, 0)
+                assert type(look_ahead) is Token
             elif action == ACCEPT:
                 break