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From: Stefan Lucks <lucks@th.informatik.uni-mannheim.de>
Newsgroups: comp.lang.ada
Subject: Re: contracted exceptions
Date: Fri, 8 Jun 2007 17:56:36 +0200
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Date: 2007-06-08T17:56:36+02:00
List-Id: <comp.lang.ada>

On Fri, 8 Jun 2007, Robert A Duff wrote:

> Ray Blaak <rAYblaaK@STRIPCAPStelus.net> writes:
>
>> The Java experience shows that compiler checked exception specifications don't
>> work.
>
>> A typical naive programmer, forced by the compiler to handle an exception,
>> overwhelmingly seems to do:
> ...
>> or even worse:
>>
>>   try
>>   {
>>     doSomething();
>>   }
>>   catch (SomeError e)
>>   {
>>   }
>
> Well, this part of the problem can't be blamed on the language.
> This code is just plain bad practise.  The solution is better
> training for programmers, not better language design:
> You should almost never silently swallow an exception
> like that, and if you do, you should always have a comment
> explaining why.

Unfortunately, this is what Ada tasks implicitely do.

If a task fails to handle an exception raised somewhere inside, the task 
silently dies -- without notifying anyone. Enforcing the subprograms used 
by the task to precisely specify "this subprogram might raise these 
exceptions and none else" would help a lot ...


-- 
Stefan Lucks      (moved to Bauhaus-University Weimar, Germany)
------  I  love  the  taste  of  Cryptanalysis  in  the  morning!  ------