Re: Writing an Operating System in Ada

[Maciej Sobczak <see.my.homepage@gmail.com>]

On 13 Sty, 10:17, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
wrote:

> > Interact with other systems? You know, you might want to sometimes
> > move your "persistent objects" to another machine.
>
> Marshaling? In terms of ADT it is assignment. Create a local object of the
> type. Assign the remote object to it. Done.

What remote object? I just plugged in my USB stick or spun the DVD in
the drive.

If you want to see a "remote object" in this operation, you will have
to somehow instruct the system that the "remote object" is the one
which is on USB. In which case there is no point in having it
(unnecessary step) as you might just as well instruct the system that
your *local* object should be constructed from what is on the drive,
by perhaps providing the file name.

Which is exactly what we have today.

The high-level OO abstraction still has to hit the bare metal at some
point, which only shows that it does not solve any problem, only moves
it elsewhere.

> > Did I mention that you might want to move you whole hard drive to
> > another machine as well? :-)
>
> Did you try?

Sure, my USB stick works fine.

> What happens with a NTFS drive in a Linux system?

I have no idea since I do not have any NTFS drives around. :-)

But I do not see how the OO approach would solve that problem. Plug
the OO-aware drive from the OO-aware system from Microsoft into your
OO-aware system of choice and you will be in the same mess.

Again, no problem solved.

(because the problem of compatibility is in standardization, not in
paradigm)

> > There is a reason why none of the pure-OO-OS-let's-do-it-correctly
> > ever really took off.
>
> Yes. There are many reasons. For all there is no consistently designed
> OOPL, Ada included. Without MI, MD, tagged tasks, there is no chance to get
> it right.

Agreed. OO cannot be done right without these sorted out first.

> But the major problem is lack of any interest, since the market
> of operating system was burnt down to the ground.

Or maybe the problem is that people try to perceive any given paradigm
as a silver bullet for solving all problems. I do not think that OO is
one (and I though the industry came to this conclusion some 15 years
ago already).
Personally, I'm not even sure if I would like to use the OS that was
made pure-OO from the ground up in all possible aspects. Some paradigm
flexibility is needed to find optimal solutions in different
situations and that cannot be achieved if a single idea is driving
everything.

--
Maciej Sobczak * www.msobczak.com * www.inspirel.com

Database Access Library for Ada: www.inspirel.com/soci-ada