02:52 < askhl> Hello.  In simple_parser.py, there are some methods that define parameters that default to empty lists, then append to those lists.  E.g. optimizeParsingTree
02:52 < askhl> That list is defined only *once* for the method
02:52 < askhl> When the function is called, it appends to that list
02:53 < askhl> That means it permanently contaminates the list
02:53 < askhl> metaInfoToKeep will successively get more elements every time that function is called
02:54 < askhl> The appropriate way to do this sort of thing is to do metaInfoToKeep=None in the parameter list, then "if metaInfoToKeep is None: metaInfoToKeep = []" within the 
               method body
02:54 < askhl> That way a new list is created for every method call
02:54 < askhl> The allMetaNames method has the same problem
02:57 < askhl> It is generally dangerous to define mutable default values as parameters
02:57 < askhl> I recommend defining them as an empty tuple.  That way if anyone ever appends to the thing, it will be an error
02:57 < askhl> (and if it's meant to be appended to, it must be a newly instantiated list)