--- a/python/testpyy.py	Sun May 26 15:28:07 2013 +0200
+++ b/python/testpyy.py	Sun May 26 23:19:27 2013 +0200
@@ -1,5 +1,5 @@
 import unittest, pprint
-from pyyacc import Grammar, Item, EOF 
+from pyyacc import Grammar, Item, EOF, ParserGenerationException
 from ppci import Token
 
 def genTokens(lst):
@@ -27,6 +27,44 @@
         p = g.genParser()
         # 4. feed input:
         p.parse(tokens)
+    def testReduceReduceConflict(self):
+        """ Check if a reduce-reduce conflict is detected """
+        # Define a grammar with an obvious reduce-reduce conflict:
+        g = Grammar([EOF, 'id'])
+        g.add_production('goal', ['a'])
+        g.add_production('a', ['b'])
+        g.add_production('a', ['c'])
+        g.add_production('b', ['id'])
+        g.add_production('c', ['id'])
+        g.start_symbol = 'goal'
+        with self.assertRaises(ParserGenerationException):
+            p = g.genParser()
+    def testShiftReduceConflict(self):
+        g = Grammar([EOF, 'if', 'then', 'else'])
+        g.add_production('if_stmt', ['if', 'then'])
+        g.add_production('if_stmt', ['if', 'then', 'else'])
+        g.add_production('stmt', ['if_stmt', 'else'])
+        g.start_symbol = 'stmt'
+        with self.assertRaises(ParserGenerationException):
+            g.genParser()
+    def testUndefinedTerminal(self):
+        """ Test correct behavior when a terminal is undefined """
+        g = Grammar([EOF, 'b'])
+        g.add_production('goal', ['a'])
+        g.add_production('a', ['b'])
+        g.add_production('a', ['c'])
+        g.start_symbol = 'goal'
+        with self.assertRaises(ParserGenerationException):
+            g.genParser()
+    def testRedefineTerminal(self):
+        """ Test correct behavior when a terminal is redefined """
+        g = Grammar([EOF, 'b', 'c'])
+        g.add_production('goal', ['a'])
+        with self.assertRaises(ParserGenerationException):
+            g.add_production('b', ['c']) # Not allowed
+        g.add_production('a', ['c'])
+        g.start_symbol = 'goal'
+        g.genParser()
 
 class testExpressionGrammar(unittest.TestCase):
     def setUp(self):