Re: Flaw in Conditions System?

From: Tayssir John Gabbour (tayss_temp2_at_yahoo.com)
Date: 03/27/04 

Date: 27 Mar 2004 07:00:05 -0800

rpw3@rpw3.org (Rob Warnock) wrote in message news:<vOKcncFKDvpU1fjd3czS-g@speakeasy.net>...
> Tayssir John Gabbour <tayss_temp2@yahoo.com> wrote:
> +---------------
> | ...did ask what the handler should return, and the spec seems
> | silent on this. Unless there's some implicit block I missed.
> +---------------
>
> Read CHLS 9.1 again. If a handler declines (by simply returning), then:
>
> "...any values returned by the handler are ignored
> and the next most recently established handler is invoked."
>
> Hardly "silent".

Not that this topic is still interesting to anyone, but I'm sure you
know I read that. I mean, come on. ;) That tired Tayssir would have
said this:

Peter asked, "According to you the condition has been 'handled' as a
consequence of that non-local exit but I'm still in my handler code.
What happens next?"

Now you chose part of the spec that talks about what happens when it's
DECLINED. But Peter's question presupposes it was HANDLED.

Tricky nut to crack, eh? I'm not glad with the wording, but it's
still the most brilliant "unusual situation" system I've seen so far,
and I've certainly asked around.

Though if you take it from the context of people who have been flamed
in the bad ol' days, when they were told READ THE CLHS!, that sucker
can be hard to read. I maintain that a good newbie lisper will see a
term like "nonlocal exit," look it up dutifully in the glossary trying
not to have any preconceptions, and think it's something other than it
is. What are you "exiting" from? The normal shape of execution? In
an age where goto-like effects are faddishly reviled, maybe it's an
"exit" from proper coding style?

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