Array subtype

AST.py

@@ -17,6 +17,8 @@ class ASTNode():
         # reachability: None = not set, True = maybe, False = no
         self.outMaybe = None # either None or True/False
 
+    def getConstant(self):
+        return None
 
     # Do certains actions on every node of the AST tree
     #   call the same method in each class and its children recursively