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From: "bubble" <bubble@riskm.com.tw>
Newsgroups: comp.lang.ada
Subject: Re: Ada exception block does NOT work?
Date: Tue, 16 Aug 2005 17:32:48 +0800
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Date: 2005-08-16T17:32:48+08:00
List-Id: <comp.lang.ada>

dear Georg:
thank to your reply so quickly.
and the problem still not be sloved.

you can test "test code".
you will find some thing interesting.


the statement ,  Avg := Sum / Data'Length;
should be throw a exception signal when Data'length is 0 (empty array)
and then the exception block handler should catch the signal, and do some 
recovery process.

in the test case, it doesn't work
in first exceptin case, Ada throw a exception and transfer the control to 
exception handler (greater).
in 2nd exception case,Ada "should" throw exception and do control transfer.
Unfortunately, it does not do.



> bubble wrote:
>
>> I found Ada can not re-enter the exception block twice.(oh! my god)
>> It should be work.
>
> It does :-). Reentering means to loop, so you could write,
> in your procedure's body
>
>   loop
>      begin
>         some_computation(data);
>         exit retrying;
>      exception
>         when Some_Exception =>
>            report;
>            make_adjustments;
>      end;
>   end loop;
>
> or
>
>   retry: loop
>      begin
>         some_computation(data);
>         exit retry;
>      exception
>         when Some_Exception =>
>            report;
>            make_adjustments;
>      end;
>   end loop retry;