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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: contracted exceptions
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Date: Fri, 8 Jun 2007 20:00:59 +0200
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Date: 2007-06-08T20:00:40+02:00
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On Fri, 08 Jun 2007 17:31:05 GMT, Ray Blaak wrote:

> Note that by "contract" I am referring only to some imaginary Ada syntax that
> indicates that a subprogram can raise a particular set of exceptions.

Then I don't see any problem with that. Consider:

if Halt (x) then
   raise Y;
end if;

the contract has Y. So you can always match such contracts statically.

Of course, Raise_Exception and Raise_Occurence from Ada.Exceptions will
have all exceptions in their contracts.

> Hm. I'm not so sure there is a disagreement as such with fault vs error. I
> guess that my point is that what the software does in response to both tends
> to be the same: report it and reset/halt/whatever.

Software and more narrowly exceptions cannot report own bugs. It would be a
very bad idea to exceptions for that, because vital information about the
reasons will be inevitably destroyed. The best possible way is to break
into debugger, stopping everything else.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de