Re: Ada OOP alternatives?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Thu, 17 Jul 2008 12:50:31 -0400, Robert A Duff wrote:

> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
> 
>> On Wed, 16 Jul 2008 21:36:28 -0400, Robert A Duff wrote:
>>
>>> So it's clearly feasible to have information in bodies used
>>> when compiling clients.
>>
>> It is feasible, but makes little sense. Why there should be bodies
>> then?
> 
> I think you mean, "Why there should be specs then?".  ;-)

I used to review C code that packed almost 80% of executable code in the
header files... (:-))

>> What is the property of a body the specification does not have, and
>> reverse?
>>
>> In other words, provided the compiler could not compile specifications
>> without bodies, why the code reader/maintainer should be able to do this?
> 
> I want separate specs and bodies, not for the compiler's benefit, but
> for the programmer's benefit.  I want to be able to read a concise spec,
> without having to wade through the entire body.

There are two problems with that. The first one is that the difference is
not obvious. Why legality check is less than "full compilation", so that
the delta cannot be left for the binder/linker. The second one is that if
the delta is sufficient, then the reader should probably become aware of
it. In short, it is difficult to drive a margin.

> The compiler should check legality without looking at other bodies.  But
> it should look at bodies when generating code (at least if optimization
> is turned on).

But what would you do with dynamically linked libraries, remote partitions
and other lately bound stuff? I think that the time of monolithic systems
is gone.

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