copy method
Returns a shallow copy of the receiver.
Override this method in all subclasses, return its own type.
Implementation
@override
EpsilonParser<R> copy() => EpsilonParser<R>(result);
Returns a shallow copy of the receiver.
Override this method in all subclasses, return its own type.
@override
EpsilonParser<R> copy() => EpsilonParser<R>(result);