comp.lang.ada
 help / color / mirror / Atom feed
From: robert_dewar@my-dejanews.com
Subject: Re: Can't export object of private type
Date: 1999/02/26
Date: 1999-02-26T00:00:00+00:00	[thread overview]
Message-ID: <7b5u87$s88$1@nnrp1.dejanews.com> (raw)
In-Reply-To: F7r2DF.23y@syd.csa.com.au

In article <F7r2DF.23y@syd.csa.com.au>,
  nospam@thanks.com.au wrote:
> Because *non-recursive* declarations imply a partial
> ordering, a valid elaboration sequence can be determined
> for them, irrespective of declaration order.

I know that seems reasonable for simple cases, but this
approach simply will not work, it is recursively
undecidable in the general case what ordering should be
used, since it depends on computational paths.

Linear elaboration is a model that enormously simplifies
the semantics of the language, and allows much more
powerful declarational forms (since it allows a general
unification of declarations and computations).

It is really fundamental to the language. The example I
gave was a very simple one, where you can imagine that
somehow it could be statically detected to be "recursive"
(note that you do NOT have a formal definition of what
you mean by recursive here, and you will find that any
attempt to formalize this definition will fail.)

The advantage of private parts is of course the nice
compartmentalization. Indeed we have on the drawing boards
for GNAT a feature to have the private parts in separate
files which will be very handy for target specialization
and indeed for general abstraction.

So that is the argument on the other side, and it is indeed
a powerful one!

But to try to compromise the notion of linear elaboration
in Ada and replace it with a notion of dependencies will
fail miserably.

-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/       Search, Read, Discuss, or Start Your Own    




  reply	other threads:[~1999-02-26  0:00 UTC|newest]

Thread overview: 128+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <F7JoCB.JxB@syd.csa.com.au>
1999-02-24  0:00 ` Can't export object of private type Don Harrison
1999-02-24  0:00   ` Samuel Mize
1999-02-24  0:00     ` Tucker Taft
1999-02-25  0:00     ` Don Harrison
1999-02-25  0:00       ` fraser
1999-02-26  0:00         ` Don Harrison
1999-02-26  0:00           ` Samuel Mize
1999-03-01  0:00             ` Don Harrison
1999-03-01  0:00               ` Matthew Heaney
1999-03-02  0:00               ` fraser
1999-03-03  0:00                 ` Don Harrison
     [not found]           ` <7b6nqe$75m$1@remarq.com>
1999-02-26  0:00             ` fraser
1999-02-27  0:00               ` Nick Roberts
1999-02-26  0:00           ` fraser
1999-03-01  0:00             ` Don Harrison
1999-03-01  0:00               ` Matthew Heaney
1999-02-28  0:00           ` Matthew Heaney
1999-02-28  0:00         ` Matthew Heaney
1999-02-25  0:00       ` Samuel Mize
1999-02-26  0:00         ` Don Harrison
1999-02-27  0:00           ` Nick Roberts
1999-03-01  0:00             ` Don Harrison
1999-03-01  0:00               ` Matthew Heaney
1999-03-01  0:00                 ` Nick Roberts
1999-03-01  0:00               ` Nick Roberts
1999-03-01  0:00                 ` Don Harrison
1999-03-02  0:00                   ` Matthew Heaney
1999-03-03  0:00                     ` Don Harrison
1999-03-03  0:00                       ` Samuel Mize
1999-03-04  0:00                         ` Don Harrison
1999-03-07  0:00                     ` Ehud Lamm
1999-03-03  0:00               ` Robert A Duff
1999-03-04  0:00                 ` Don Harrison
1999-03-04  0:00                   ` Robert A Duff
1999-03-01  0:00             ` Don Harrison
1999-03-02  0:00               ` Matthew Heaney
1999-02-28  0:00         ` Matthew Heaney
1999-03-01  0:00           ` Samuel Mize
1999-03-01  0:00           ` Nick Roberts
1999-03-01  0:00             ` Matthew Heaney
1999-03-02  0:00               ` Nick Roberts
1999-03-01  0:00             ` Matthew Heaney
1999-02-25  0:00       ` robert_dewar
1999-02-26  0:00         ` Don Harrison
1999-02-26  0:00           ` robert_dewar [this message]
1999-02-26  0:00             ` dennison
1999-02-26  0:00             ` bourguet
1999-02-26  0:00               ` Samuel T. Harris
1999-02-27  0:00                 ` Jean-Pierre Rosen
1999-02-27  0:00                 ` Simon Wright
1999-02-28  0:00               ` dewar
1999-03-01  0:00                 ` bourguet
1999-03-01  0:00             ` Don Harrison
1999-03-01  0:00               ` robert_dewar
1999-03-03  0:00                 ` Don Harrison
1999-03-03  0:00                   ` robert_dewar
1999-03-01  0:00             ` Stephen Leake
1999-02-27  0:00         ` Brian Rogoff
1999-03-01  0:00           ` robert_dewar
1999-02-28  0:00       ` Matthew Heaney
1999-03-01  0:00       ` Tom Moran
1999-03-02  0:00         ` Matthew Heaney
1999-03-02  0:00           ` Tom Moran
1999-03-02  0:00             ` Matthew Heaney
1999-03-02  0:00               ` Tom Moran
1999-03-02  0:00                 ` Matthew Heaney
1999-03-02  0:00                   ` nabbasi
1999-03-02  0:00                     ` Matthew Heaney
1999-03-03  0:00                   ` Don Harrison
1999-03-03  0:00                     ` Single Extension; Polymorphic Arrays Nick Roberts
1999-03-03  0:00                       ` Nick Roberts
1999-03-08  0:00                         ` Matthew Heaney
1999-03-08  0:00                           ` Nick Roberts
1999-03-08  0:00                           ` Tucker Taft
     [not found]                             ` <m3ogm40wav.fsf@mheaney.ni.net>
1999-03-08  0:00                               ` Nick Roberts
1999-03-08  0:00                               ` Tucker Taft
1999-03-08  0:00                                 ` dennison
1999-03-09  0:00                                 ` Nick Roberts
1999-03-03  0:00               ` Can't export object of private type Don Harrison
1999-03-03  0:00                 ` Don Harrison
1999-03-03  0:00                   ` Nick Roberts
1999-03-04  0:00                     ` Don Harrison
1999-03-04  0:00                       ` fraser
1999-03-09  0:00                         ` Don Harrison
1999-03-04  0:00                       ` Nick Roberts
1999-03-08  0:00                         ` Matthew Heaney
1999-03-09  0:00                         ` Don Harrison
1999-03-09  0:00                           ` Matthew Heaney
1999-03-09  0:00                             ` Nick Roberts
1999-03-10  0:00                             ` Don Harrison
1999-03-10  0:00                               ` Matthew Heaney
1999-03-04  0:00                       ` Nick Roberts
1999-03-04  0:00                         ` robert_dewar
1999-03-05  0:00                           ` Nick Roberts
1999-03-05  0:00                         ` Robert A Duff
1999-03-05  0:00                           ` Abstract Subprograms of Untagged Types Nick Roberts
1999-03-05  0:00                             ` Tucker Taft
1999-03-05  0:00                               ` Nick Roberts
1999-03-06  0:00                               ` robert_dewar
1999-03-05  0:00                             ` robert_dewar
1999-03-08  0:00                     ` Can't export object of private type Matthew Heaney
1999-03-08  0:00                       ` Nick Roberts
1999-03-08  0:00                 ` Matthew Heaney
1999-03-10  0:00                   ` Don Harrison
1999-03-10  0:00                     ` Matthew Heaney
1999-03-10  0:00                       ` dennison
1999-03-10  0:00                         ` Robert A Duff
1999-03-10  0:00                           ` dennison
1999-03-11  0:00                             ` dennison
1999-03-10  0:00                           ` robert_dewar
1999-03-10  0:00                         ` robert_dewar
1999-03-10  0:00                           ` dennison
1999-03-10  0:00                             ` robert_dewar
1999-03-10  0:00                               ` dennison
1999-03-11  0:00                                 ` robert_dewar
1999-03-11  0:00                                   ` Don Harrison
1999-03-12  0:00                                     ` robert_dewar
1999-03-11  0:00                                 ` bill
1999-03-11  0:00                                   ` Scott Ingram
1999-03-11  0:00                                     ` Larry Kilgallen
1999-03-11  0:00                                   ` dennison
1999-03-12  0:00                                   ` dewar
1999-03-11  0:00                                 ` dennison
1999-03-11  0:00                           ` Don Harrison
1999-03-03  0:00           ` Don Harrison
1999-02-28  0:00     ` Matthew Heaney
1999-02-24  0:00   ` Tom Moran
1999-02-28  0:00   ` Matthew Heaney
replies disabled

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox