copy method
Creates a shallow copy of this parser.
Overridden in subclasses to return an instance of the specific parser type.
Implementation
@override
PickParser<R> copy() => PickParser<R>(delegate, index);
Creates a shallow copy of this parser.
Overridden in subclasses to return an instance of the specific parser type.
@override
PickParser<R> copy() => PickParser<R>(delegate, index);