I hope this doesn't come across as adversarial since I am sincerely interested in this, but I am troubled by the sideways composition paper. It seems as if it is an existence proof that the id object model's intention of having "messaging semantics that are described entirely in terms of those same objects and messages" is not attained. Implementing sideways composition required changing send and bind which are not redefinable within the system. Only lookup can be redefined in the vtable. The sideways composition as implemented is still not able to handle multiple delegates. There isn't a way for an object A that wants to delegate first to B and then to C (if B does not already itself delegate to C). The single delegation mechanism is hard coded in bind which is not redefinable from within.
-- --- james mccartney _______________________________________________ fonc mailing list [email protected] http://vpri.org/mailman/listinfo/fonc
