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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Ada 2012 Constraints (WRT an Ada IR)
Date: Tue, 6 Dec 2016 17:15:52 -0600
Organization: JSA Research & Innovation
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Date: 2016-12-06T17:15:52-06:00
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"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:o24phv$1ou6$1@gioia.aioe.org...
> On 2016-12-05 23:12, Randy Brukardt wrote:
...
>> Until you compare to the alternative, which is a subprogram body that 
>> gives
>> the wrong answer without detection. As I said in another message, a 
>> visible
>> bug is much better than an invisible bug.
>
> The alternative is a contract to raise exception. So there is no bug 
> anymore, just well-defined behavior.

All contracts raise an exception (I'm pretty sure Assertion_Error is an 
exception :-).

Moreover, most contracts (at least the ones I'd write) raise specific 
exceptions (not Assertion_Error). Indeed, this is a far better way to define 
something that raises an exception than an English comment. (Which is the 
only other alternative for the specification - and its the specification 
that matters, not the body.)

                       Randy.


                      Randy.