Code cleanup and updated pybison version.

external/pybison

@@ -1 +1 @@
-Subproject commit 260359e31ceeaa46d26a26303e08cda37c7578f5
+Subproject commit b200b18e408400386c30c59572a6c72805d2ca87

src/parser.py

@@ -63,6 +63,9 @@ class Parser(BisonParser):
     # override default read method with a version that prompts for input
     # ------------------------------------------------------------------
     def read(self, nbytes):
+        if self.file == sys.stdin and self.file.closed:
+            return ''
+
         try:
             return raw_input('>>> ') + '\n'
         except EOFError:
@@ -187,24 +190,24 @@ class Parser(BisonParser):
         """
 
         if option in [0, 1]:  # rule: exp IDENTIFIER | exp NUMBER
-            # NOTE: xy -> x*y
-            # NOTE: (x)4 -> x*4
+            # example: xy -> x*y
+            # example: (x)4 -> x*4
             val = int(values[1]) if option == 1 else values[1]
             return Node('*', *(combine('*', values[0]) + [Leaf(val)]))
 
         if option == 2:  # rule: exp LPAREN exp RPAREN
-            # NOTE: x(y) -> x*(y)
+            # example: x(y) -> x*(y)
             return Node('*', *(combine('*', values[0])
                               + combine('*', values[2])))
 
         if option == 3:
-            # NOTE: x4 -> x^4
+            # example: xy4 -> x*y^4
             identifier, exponent = list(values[1])
             node = Node('^', Leaf(identifier), Leaf(int(exponent)))
             return Node('*', values[0], node)
 
         if option == 4:
-            # NOTE: x4 -> x^4
+            # example: x4 -> x^4
             identifier, exponent = list(values[0])
             return Node('^', Leaf(identifier), Leaf(int(exponent)))
 

tests/parser.py

@@ -83,7 +83,7 @@ def run_expressions(base_class, expressions, keepfiles=1, fail=True,
         try:
             res = parser.run([exp])
             assert res == out
-        except:
+        except:  # pragma: nocover
             if not silent:
                 print >>sys.stderr, 'error: %s = %s, but expected: %s' \
                                     % (exp, str(res), str(out))

tests/test_parser.py

@@ -23,3 +23,6 @@ class TestParser(unittest.TestCase):
 
     def test_line(self):
         self.assertEqual(line(Parser, '4a'), '4 * a')
+
+    #def test_raise(self):
+    #    ParserWrapper(Parser).run(['raise'])