Issue: EXIT-EXTENT (Version 5)

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: Thu, 15 Dec 88 22:02:42 PST
    From: Jon L White <jonl@lucid.com>

    I wanted to recommend against accepting this proposal in its current
    format; it looked like to me that a lot more work was needed to make
    it both accurate and comprehensible.  

I agree with that for version 5.  I'm not sure whether I agree with that
for the earlier versions, I would have to go back and re-read them.

					  Since I don't have the time to
    work on it before the January meeting, I won't be able to explain
    my objections in much better detail (without, in fact, going to the
    trouble to prepare the necessary revised proposal, which I don't
    have time to do!)

    What would you like to see happen?  If you think you can do it in time 
    before the January meeting, could you _please_ make the revision, and
    mail that out?  to X3J13 as well?

I'd help if I could, but I cannot revise the proposal in its current
two-proposal form, because I cannot think of any coherent, unambiguous,
implementation-independent way to say what I think the second proposal is
trying to say.  At this point it wouldn't surprise me if it turns out to be
impossible to specify it in any acceptable way.  If someone else can come
up with it, fine, I'd love to be proved wrong.

If that doesn't happen, I'd like to see either the first proposal (the one
that ends the dynamic extent of an exit sooner) accepted or retain the
status quo.  I think the status quo, which is vague, ambiguous, and
incoherent, would still be better than adopting a new proposal that (I
feel) is still ambiguous and incoherent, and at the same time is
incompatible with current practice.  As I commented earlier, I think
version 5 of the second proposal (the one that ends the dynamic extent of
an exit later) is in fact incompatible with all current implementations,
and may not be implementable at all.  I don't think that was what was
intended, but even what was probably intended is incompatible with some
current implementations (Genera is the one I know about).