clearStack     p       = ParsingData (accepted p) (parsingError p) (acceptedValue p) (clear (parsingStack p))
clearStack     p       = ParsingData (accepted p) (parsingError p) (acceptedValue p) (clear (parsingStack p))
clearStack     p       = ParsingData (accepted p) (parsingError p) (acceptedValue p) (clear (parsingStack p))