This is not a node in the classic sense in that it has no defined or
interpret method which can be called. It just stores the position of
the literal and the name/value of the literal. We made it a node so that
the parser needs to work less hard in its productions. dynamic literals
are nodes and by having literals also be nodes means they have a common
subtype which is not Object.
Accept for the visitor pattern.
iVisitor the visitor