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initialize-instance on an exisiting instance
Date: 19 Oct 87 09:01 PDT
From: Danny Bobrow <Bobrow.pa@Xerox.COM>
We did not discuss this, but if a user calls
on an existing instance, it seems that it should work. This would be a
way of reinitializing an instance. Is there any problem with this? I
would rather this be true than say "it is an error" to initialize an
instance more than once.
Given what we said about permissible optimizations in initialize-instance, I
don't see how the semantics of this operation could be well-defined, unless
this isn't really the same initialize-instance that make-instance calls.
That might be reasonable: change "permissible optimizations in
initialize-instance" to "permissible optimizations in initialize-instance
when called by make-instance."
However, I'm not sure that calling initialize-instance on an existing
instance is going to be a particularly useful operation. Does it first
reset all the slots to uninitialized? Regular initialize-instance doesn't
do that. What if there are user-defined initialize-instance methods that
do such things as adding the instance to an auxiliary data structure? Can
they tolerate adding it twice? Or should one call a new function
deinitialize-instance before calling initialize-instance?