Filter all tokens dynamically instead of a predefined list.

external/pybison

@@ -1 +1 @@
-Subproject commit 4fac41ac1cd069d5ad889efccc00428d24583a5d
+Subproject commit 2b1f8fd1b1055dc9f0e24fea7eae7be45c041882

src/parser.py

@@ -154,7 +154,7 @@ class Parser(BisonParser):
             left, right = filter(None, match.groups())
 
             # Filter words (otherwise they will be preprocessed as well)
-            if left + right in ['graph', 'raise']:
+            if (left + right).upper() in self.tokens:
                 return left + right
 
             # If all characters on the right are numbers. e.g. "a4", the