> But the general problem is tricky. What about reference objects contained > in attributes or slots of other objects, etc? What is needed for total > copying is a switch in the low-level duplication code that says to copy > reference objects. It's also possible that one does NOT want all such > objects copied.
Good point. I wonder what other languages do? And in fact, are there any other languages that mix mutable and non-mutable objects in this way? Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel