New Model structure

[Mark S. Miller <mark>]

Date: Sat, 28 Oct 89 18:45:26 PDT
   From: tribble (Eric Dean Tribble)

   Why should it be a set?  (I'm neutral, but I want a reason to go
   one way or the other).

Sets are simpler, so if it can be both, it should be a set.  Looked at
another way, it should be a bag if the model needs to record each
dependent once for every time the dependent registers itself.  As
opposed to simply recording which dependents have registered
themselves.  The only circumstances in which this would make sense to
me is: if dependent D registers itself with model M three times, and M
changes, broadcasting update record U to its dependents, then M must
send U to D three times.  I can't imagine why this would be.

Besides, I want to get away without us having to have a class Bag, so
I've got a vested interest in saying it should be a Set.