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Re: exception systems
From: kelsey@research.nj.nec.com (Richard Kelsey)
Subject: Re: exception systems
Date: Thu, 18 Apr 1996 19:02:55 -0400
>
> References: <199604181941.PAA15530@sting14>
> Date: Thu, 18 Apr 1996 18:15:59 -0400
> From: Matthias Blume <blume@CS.Princeton.EDU>
>
> I still think there is way too much in it. Where is MI suddenly
> coming from? If I recall correctly, we don't even have SI in Scheme
> -- and I'm very happy about this fact.
>
> So am I. My initial reaction to multiple-inheritance was Uuugh!
> I changed my mind when I was unable to come up with an reasonable
> alternative. Note that I am not suggesting adding multiple
> inheritance for anything other than conditions.
But shouldn't this prompt us to ask why we seem to need this `feature'
at all. ``Programming languages should be designed...''
> I think you are missing the point. The issue isn't functionality.
> As I said in the proposal it could all be implemented easily in
> Scheme. The issue is interfaces. The notion is that you should
> be able to say for procedure <foo>:
>
> If <foo>'s argument is not a <bar> it installs an <interactive>
> restart that accepts a new argument and then signals a <wrong-
> type-argument> condition.
`wrong-type-argument' shouldn't be a run-time issue at all. But this
has been discussed and disagreed-on before.
> I would be perfectly happy with something as simple as
> `raise'/`handle'.
>
> Which is exactly what I proposed originally. The consensus
> was that it was completely inadequate. You didn't comment at
> the time.
My mistake.
------------------------
I have realized before that Scheme is not moving in a direction that I
can agree with. This whole exceptions thing is just another instance
of this phenomenon. When I came to Scheme I liked it for its
simplicity and clarity, which explains why I now dislike it more and
more.
If I were interested in a Common Lisp, I'd know where to find it.
Regards,
-Matthias