On 7/5/2006 3:47 PM, Gabor Grothendieck wrote: > On 7/5/06, Duncan Murdoch <[EMAIL PROTECTED]> wrote: >> On 7/5/2006 2:23 PM, Gabor Grothendieck wrote:
>> I think by this time I have shown that subclassing of >> > environments does not work yet it could if it were designed differently >> > and furthermore there are significant problems with the workarounds. >> >> I don't think you've shown that subclassing of environments doesn't >> work. You have an example that shows that shows that R implements >> Henrik's "Case 2" rather than his "Case 1", but as Thomas and I said, >> that really has nothing to do with subclassing. >> >> Subclassing is about defining a new class, not about copying objects. >> You can (and did!) define a new class which inherits from the >> environment class. > > But by subclassing in the way allowed one comes up with something that > is not useful. You haven't shown that. Show an example where you define a new class that should inherit from environment but doesn't. All you've shown so far is that when you try to change the class of an object to a new class, it appears that the class of another object also changes. (The explanation being that they are really just different names for the same object.) > That is why tcltk and Henrik's package wrap environments in lists and define > a completely different class but by doing that they are not able to take > advantage of inheritance. I think they did that because they wanted explicit references to objects, rather than the built-in implicit ones. I've wanted explicit references to things on a number of occasions too, but that's really unrelated to inheritance as far as I can see. Duncan Murdoch ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
