On Wed, 10 Jul 2002, Dan Sugalski wrote: > >What bothers me is this: the programmer needs to be able to predict > >what the machine is going to do with the code she gives it. > >And predicting how the machine is going to resolve the multimethod > >call could be, in any but trivial cases, far too difficult. > >Programmers will end up guessing -- or, even worse, not giving it > >a single thought -- and then we may as well be programming in PL/1. > >:-) > > Yeah, this definitely true, and I've been told it's an issue when there > are multiple routines that are almost, but not quite, correct. > > One place where we make it easier on ourselves at this level is > restricting the inheritance hierarchy. Since pretty much everything > inherits directly from default it's pretty simple to predict.
I think that this inheritance stuff should be talked about before we run too far with this. Do we really want *two* inheritance trees per object in Perl 6? One language-level and one PMC-level? How would that even work? Right now the whole concept of "PMC Inheritance" is purely just a way to save implementors some typing. There is really no inheritance of any kind going on, it just sticks pointers to the default functions into the vtable structure method entries for undefined methods. I'm inclined to say that vtables shouldn't inherit at all, but I may be missing something important. I usually am. - D <[EMAIL PROTECTED]>
