Re: Ada & Posix

Re: Ada & Posix

[Markus Kuhn]

Jerry van Dijk wrote:
> It would be great if we would have Posix bindings on
> the major platforms with all compilers, as that would
> remove a lot of environment dependenties in our code.

Fully agreed! Adding a good POSIX.5 binding with man pages
to the GNAT distribution should help a lot to make Ada an
attractive system programming language for Unix systems.

> 1) Anyone willing to do such a binding will first have
>     to spend money on buying a standard;

Expensive paper-only standards are a real hazzle for non-commercial
(academic) users. Suggesting your local university library to get
a copy is probably the best approach.

> So, I am not suprised that -AFAIK- no Ada vendors
> are rushing to get the standard implemented.

And as a consequence, not much portable system programming for
Unix in Ada seems to be going on at the moment and GNAT seems to
be mostly used for teaching the language since C development
environments still provide a much richer API at the moment
and every Ada developer has to first come up with his private
subet binding to the C libraries before he can start with the
actual project.

Markus

-- 
Markus G. Kuhn, Security Group, Computer Lab, Cambridge University, UK
email: mkuhn at acm.org,  home page: <http://www.cl.cam.ac.uk/~mgk25/>

Re: Ada & Posix

[Robert Dewar]

Markus says

<<And as a consequence, not much portable system programming for
Unix in Ada seems to be going on at the moment and GNAT seems to
be mostly used for teaching the language since C development
environments still provide a much richer API at the moment
and every Ada developer has to first come up with his private
subet binding to the C libraries before he can start with the
actual project.
>>

Actually GNAT is being used in a wide variety of large scale commercial
projects on Unix. Some customers have indeed been interested in a Posix
interface, which is why we are working with Ted Baker's team at FSU to
integrate Florist with the GNAT release.

However, in our experience there are many users of GNAT under Unix who
prefer to use pragma Import to get at whatever facilities they need, or
who are using other bindings. The demand for a Posix interface is by
no means as universal as Markus seems to think it is.

Of course I understand the "if only Ada 95 provided XXX, then all the
world would flock from C/C++ to Ada 95."  I look on all such claims
with what the US Secretary of Defence called an "Ohio attitude", namely
I won't be convinced till I see some evidence that such a claim is true :-)

Robert Dewar
Ada Core Technologies

Re: Ada & Posix

[Brian Rogoff]

On 23 Feb 1998, Robert Dewar wrote:
> Of course I understand the "if only Ada 95 provided XXX, then all the
> world would flock from C/C++ to Ada 95."  I look on all such claims
> with what the US Secretary of Defence called an "Ohio attitude", namely
> I won't be convinced till I see some evidence that such a claim is true :-)

Totally off topic, but are you sure that shouldn't be a "Missouri attitude"? 
I must be culturally unsophisticated or something, but I thought that 
particular weltanschauung was a characteristic of the "show me" state. 
Which Ohio reference am I missing here?

Also, if Ada 95 provided XXX, we'd be within our rights to spam the world 
with "ADULTS ONLY: Ada 95 does XXX!!!" :-)

-- Brian

X-Rated Ada [slightly rude]

[Nick Roberts]

Brian Rogoff wrote in message ...
>On 23 Feb 1998, Robert Dewar wrote:
[...]
>Also, if Ada 95 provided XXX, we'd be within our rights to spam the world
>with "ADULTS ONLY: Ada 95 does XXX!!!" :-)


Or would that be Ada 69?

(AA: if you are looking down on us now: only kidding :-)

Re: Ada vs. Posix -- the battle continues

[mjl]

In article <7053@hubcap.clemson.edu> billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu writes:
>> In particular, the
>> ordinary systems which most people will be seeing in front of them for the
>> next 5 - 15 years, UNIX systems and PCs, will not run Ada accepteably.
>
>
>   A prime example is Unix; the current POSIX effort aims to 
>   standardize 1960's technology, thus resulting in a "lowest
>   common denominator" which locks users into obsolescence.

Actually, both Unix and Ada are products of the 1970's.  The difference
is that Unix, being primarily of commercial interest, has been able to
evolve, whereas Ada, a government sponsored thing-a-ma-bob, has
stagnated.  It's a shrine to the ideas of 1975, both good and bad.  The
fact that Unix has evolved in ways incompatible with Ada says as at
least as much about Ada as it does about Unix.

I followed the development of Ada from its inception as Strawman, and
became increasingly more depressed as the work proceeded.  The good
concepts Ada embodies are overwhelmed by its complexity (see Hoare's
excellent discussion of this in his Turing Lecture -- all of his
comments still apply).

Ada is the PL/I of the 70's, unusable until the mid-80's; is it destined
to be the choke-collar of DoD software development in the 90's?

Mike Lutz
Mike Lutz	Rochester Institute of Technology, Rochester NY
UUCP:		{rutgers,cornell}!rochester!rit!mjl
INTERNET:	mjlics@ultb.isc.rit.edu

Re: Ada & Posix

[William Thomas Wolfe, 2847]

From mjl@cs.rit.edu:
> Actually, both Unix and Ada are products of the 1970's.  The difference
> is that Unix, being primarily of commercial interest, has been able to
> evolve, 

   Thus generating the need for the POSIX effort.  Ada, on the 
   other hand, standardized itself to start with.  Furthermore, 
   its definition was frozen for ten years precisely in order to
   provide vendors with the ability to amortize their investments
   over that period of time.  Ada has always had its portability,
   whereas Unix is just now struggling to achieve it.

   Now that Unix is finally standardizing, work is also in progress
   (in the IEEE 1003.5 committee) to develop a standardized Ada binding
   to the IEEE 1003.1 POSIX standard.  From AlsyNews, September 1989:

      Ada applications will have a major portability advantage
      over C applications because Ada's strong typing will assure
      that an application accesses only the services that are in
      the POSIX packages.  A C application might inadvertently mix
      portable POSIX services with non-portable services provided
      by the local operating system.

   A full IEEE ballot on the Ada binding to POSIX is expected by year-end.


   Bill Wolfe, wtwolfe@hubcap.clemson.edu

Re: Ada & Posix

[William Thomas Wolfe, 2847]

From billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu:
>    Ada has always had its portability,
>    whereas Unix is just now struggling to achieve it.

   Consider also this quote from last Wednesday's Wall Street Journal:

      Currently, about 9% of the world's computers run Unix.
      It was feared that the computer industry's inability to
      agree on a single version of Unix would slow its spread.
      But because there is now a potential standard version of
      Unix, the operating system's popularity is expected to
      surge.  Analysts estimate that more than a quarter of the
      computer systems will run Unix by 1993.  "Having a clear
      common [standard] will encourage the perception that Unix
      is a mainstream product," said Eric Schmidt, vice president 
      of Sun Microsystems Inc.'s general systems group.

   Contrary to what some Usenetters seem to think, Unix is by no
   means universal; it is only recently discovering the need to
   impose the discipline of standardization, so that it might seek 
   more than its present single-digit level of market share.
 

   Bill Wolfe, wtwolfe@hubcap.clemson.edu