Re: Help understanding the benefits of Ada's exception model

[Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>]

On 06/26/2014 07:28 AM, Patrick wrote:
> Sorry for answering my own post. I think I have not used the terms unchecked
> exception and check exceptions properly.  Better terms would be handling
> exceptions and handling error codes.

The pitfalls of relying on error codes are well documented, the most obvious 
being the numerous cases where they're not checked. An exception cannot be ignored.

What is ideal is code that offers a check to avoid causing the exception, while 
raising the exception if the check is not used:

if not Stack.Is_Empty then
    Stack.Pop (Item => V);

    -- Use V
end if;

but

Stack.Pop (Item => V); -- raises Empty if Stack.Is_Empty

-- 
Jeff Carter
"Many times we're given rhymes that are quite unsingable."
Monty Python and the Holy Grail
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