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From: dgibson@snoopy.cis.ohio-state.edu (david scott gibson)
Subject: Re: Multiple Type Interfaces
Date: 1997/01/28
Date: 1997-01-28T00:00:00+00:00	[thread overview]
Message-ID: <5cm4raINN6ru@snoopy.cis.ohio-state.edu> (raw)
In-Reply-To: 32EE6EF2.2487@watson.ibm.com


In article <32EE6EF2.2487@watson.ibm.com>,
Norman H. Cohen <ncohen@watson.ibm.com> wrote:
>Dave Gibson wrote:
>

>> When Ada83 evolved into Ada95, the concept of multiple type
>> components (packages) survived, but was excluded when it came to
>> OO-style (extendable) tagged types.

>
>Not true.  It's perfectly possible for an Ada-95 package to provide two
>different tagged types.  This might be done, for example, because the
>two types share parts of their (hidden) implementations. 
>
>If a package provides two types, T1 and T2, you cannot declare a
>subprogram in the package that has both a controlling operand (i.e., a
>parameter or a function result) of type T1 and one of type T2, because
>it would not be obvious in this case which operand's tag should control
>dispatching.  However, you can have one operand of type T1 (controlling
>dispatching) and one of type T2'Class (not controlling dispatching) or
>the other way around.

Okay, but then assume you want to extend this *package* by adding some
new operations to T2 (but not T1).  If you extend T2, what happens to
the operation which had T2'Class as a parameter.  My understanding is
that it would not be present in the interface of the new package, thus
the new package would not be a true extension of the original one.
What I was talking about (as applied to Ada) is really package
extension, not type extension.

Dave
--
dgibson@cis.ohio-state.edu





  reply	other threads:[~1997-01-28  0:00 UTC|newest]

Thread overview: 379+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-01-16  0:00 OO, C++, and something much better! Jon S Anthony
1997-01-17  0:00 ` Don Harrison
1997-01-16  0:00   ` Matthew Heaney
1997-01-17  0:00     ` Alan Lovejoy
1997-01-17  0:00       ` Norman H. Cohen
1997-01-17  0:00         ` Alan Lovejoy
1997-01-18  0:00           ` Fergus Henderson
1997-01-17  0:00             ` Alan Lovejoy
1997-01-20  0:00               ` Fergus Henderson
1997-01-19  0:00                 ` Alan Lovejoy
1997-01-20  0:00               ` Damon Feldman
1997-01-19  0:00                 ` Alan Lovejoy
1997-01-20  0:00                   ` Graham Hughes
1997-01-21  0:00                     ` Alan Lovejoy
1997-01-21  0:00                       ` Marc Robertson
1997-01-24  0:00                         ` Mark Windholtz
1997-01-27  0:00                           ` David Hanley
     [not found]                             ` <32EE2FEE.62FE@p <32EE8415.2F5B@netright.com>
1997-01-28  0:00                               ` Eric Clayberg
1997-01-29  0:00                                 ` David Hanley
1997-01-29  0:00                                   ` Eric Clayberg
1997-01-28  0:00                             ` David Hanley
1997-01-28  0:00                             ` Eric Clayberg
1997-01-28  0:00                         ` Alan Lovejoy
1997-01-29  0:00                           ` Matt Kennel
1997-01-30  0:00                             ` Alan Lovejoy
1997-01-30  0:00                               ` David L. Shang
1997-01-30  0:00                               ` Black box or white box (Re: OO, C++, and something much better!) David L. Shang
1997-01-29  0:00                         ` OO, C++, and something much better! Jun Nolasco
1997-01-21  0:00                       ` Matt Kennel
1997-01-22  0:00                       ` Fergus Henderson
1997-01-22  0:00                         ` Fergus Henderson
1997-01-22  0:00                         ` Eric Clayberg
1997-01-22  0:00                           ` Graham Hughes
1997-01-23  0:00                             ` Eric Clayberg
1997-01-23  0:00                               ` Claus Reinke
1997-01-25  0:00                                 ` Eric Clayberg
1997-01-25  0:00                                   ` Lawrence G. Mayka
1997-01-25  0:00                                   ` Fergus Henderson
1997-01-28  0:00                                   ` Claus Reinke
1997-01-24  0:00                               ` Don Harrison
1997-01-24  0:00                                 ` Eric Clayberg
1997-01-28  0:00                                   ` Don Harrison
1997-01-23  0:00                             ` Mark Woodruff
1997-01-24  0:00                             ` Richard A. O'Keefe
     [not found]                               ` <E4voIF.86o@world.std.com>
1997-02-12  0:00                                 ` Ulf Schuenemann
1997-01-23  0:00                           ` Robb Nebbe
1997-01-23  0:00                             ` David Hanley
1997-01-25  0:00                             ` Eric Clayberg
1997-01-23  0:00                           ` Matt Kennel
1997-01-25  0:00                             ` Eric Clayberg
1997-01-27  0:00                             ` Jon S Anthony
1997-01-24  0:00                           ` Fergus Henderson
1997-01-24  0:00                             ` Alan Lovejoy
1997-01-26  0:00                             ` Fergus Henderson
     [not found]                             ` <32E9BAAC. <5ce8t3$6gv@mulga.cs.mu.OZ.AU>
1997-01-28  0:00                               ` Alan Lovejoy
1997-01-28  0:00                             ` Alan Knight
1997-01-29  0:00                               ` Nick Leaton
1997-01-29  0:00                             ` Fergus Henderson
1997-01-30  0:00                             ` Alan Lovejoy
1997-01-24  0:00                           ` Richard A. O'Keefe
1997-01-25  0:00                         ` Joachim Durchholz
1997-01-27  0:00                         ` Rolf Breuning
1997-01-27  0:00                         ` Ed Shirk
1997-01-20  0:00                   ` Bill Gooch
1997-01-20  0:00                   ` David Hanley
1997-01-21  0:00                     ` Alan Lovejoy
1997-01-22  0:00                       ` Fergus Henderson
1997-01-22  0:00                         ` Alan Lovejoy
1997-01-23  0:00                         ` Bob Jarvis
1997-01-22  0:00                   ` Damon Feldman
1997-01-29  0:00                   ` Joachim Durchholz
1997-01-25  0:00                 ` Jon S Anthony
1997-01-25  0:00                 ` Eric Clayberg
1997-01-26  0:00                   ` Robert Dewar
1997-01-27  0:00                     ` Bob Jarvis
1997-01-27  0:00                       ` Robert Dewar
1997-01-27  0:00                         ` Eric Clayberg
1997-01-29  0:00                           ` Robert Dewar
1997-01-29  0:00                             ` Robert A Duff
1997-01-29  0:00                               ` Eric Clayberg
1997-01-27  0:00                         ` Matthew Heaney
1997-01-27  0:00                         ` Robert A Duff
1997-01-29  0:00                           ` Robert Dewar
1997-01-27  0:00                         ` Eric Clayberg
1997-01-27  0:00                     ` Samuel S. Shuster
1997-01-27  0:00                       ` Richard Kenner
1997-01-29  0:00                         ` Robert Dewar
1997-01-30  0:00                           ` Eirik Mangseth
1997-01-28  0:00                       ` Jun Nolasco
1997-01-29  0:00                       ` Robert Dewar
1997-01-29  0:00                         ` Richard Kenner
1997-01-29  0:00                           ` David Hanley
1997-01-29  0:00                             ` Richard Kenner
1997-01-30  0:00                           ` Nick Leaton
1997-01-30  0:00                             ` Richard Kenner
1997-01-30  0:00                               ` Nick Leaton
1997-01-30  0:00                             ` Robert Dewar
1997-01-28  0:00                     ` Robert I. Eachus
1997-02-08  0:00                   ` Robin Rosenberg
1997-01-27  0:00                 ` Eric Clayberg
1997-01-29  0:00                   ` Fergus Henderson
1997-01-29  0:00                   ` Joachim Durchholz
1997-01-27  0:00                 ` Jon S Anthony
1997-01-27  0:00                 ` David Hanley
1997-01-29  0:00                   ` Joachim Durchholz
1997-01-29  0:00                     ` Dennis Smith
1997-01-28  0:00                 ` Eric Clayberg
1997-01-28  0:00                   ` Matt Kennel
1997-01-28  0:00                 ` David Hanley
1997-01-28  0:00                   ` Jacqueline U. Robertson
1997-01-29  0:00                     ` David Hanley
1997-01-29  0:00                     ` Fergus Henderson
1997-01-30  0:00                     ` Robert C. Martin
     [not found]                       ` <5cr068$gpa@uni.library.ucla.edu>
1997-06-27  0:00                         ` David Shang
1997-06-28  0:00                           ` Ronald E Jeffries
1997-06-28  0:00                           ` Mike Stark
1997-06-29  0:00                           ` Mike Anderson
1997-06-29  0:00                             ` Robert Dewar
1997-06-30  0:00                               ` Kohler Markus
1997-01-29  0:00                   ` Joachim Durchholz
1997-01-28  0:00                 ` Robert I. Eachus
1997-01-28  0:00                 ` Luther Hampton
1997-01-28  0:00                 ` David Hanley
1997-01-29  0:00                 ` Eric Clayberg
1997-01-29  0:00                 ` David Hanley
1997-01-29  0:00                 ` Eric Clayberg
1997-01-29  0:00                 ` Rolf Breuning
1997-01-29  0:00                 ` Jon S Anthony
1997-01-25  0:00               ` Robert Dewar
1997-01-26  0:00                 ` James O'Connor
1997-01-26  0:00                   ` Robert Dewar
1997-01-26  0:00                   ` George Wolke
1997-01-27  0:00                   ` Jerry van Dijk
1997-01-28  0:00                     ` Robert A Duff
1997-01-28  0:00                       ` Jerry van Dijk
1997-01-29  0:00                       ` Stanley R. Allen
1997-01-30  0:00                         ` Robert A Duff
1997-01-28  0:00                 ` Alan Lovejoy
1997-01-28  0:00                 ` Jon S Anthony
1997-01-29  0:00                   ` Robert A Duff
1997-01-25  0:00               ` Robert Dewar
1997-01-27  0:00                 ` Bob Jarvis
1997-01-27  0:00                   ` Robert Dewar
1997-01-28  0:00                 ` Alan Lovejoy
1997-01-19  0:00             ` Soren Skogstad Nielsen
1997-01-20  0:00             ` Joachim Durchholz
1997-01-26  0:00               ` Joachim Durchholz
1997-01-29  0:00                 ` Multiple Type Interfaces Jon S Anthony
1997-01-28  0:00               ` Dave Gibson
1997-01-28  0:00                 ` Robert A Duff
1997-01-28  0:00               ` Norman H. Cohen
1997-01-28  0:00                 ` david scott gibson [this message]
1997-01-28  0:00                   ` Matthew Heaney
1997-01-29  0:00                     ` david scott gibson
1997-01-29  0:00                       ` Robert A Duff
1997-01-29  0:00                         ` david scott gibson
1997-01-21  0:00             ` OO, C++, and something much better! Matthew S. Whiting
1997-01-21  0:00             ` Matthew S. Whiting
1997-01-22  0:00               ` Fergus Henderson
1997-01-22  0:00                 ` Alan Lovejoy
1997-01-22  0:00                 ` Don Harrison
1997-01-22  0:00                   ` John Kuszewski
1997-01-23  0:00                     ` Don Harrison
1997-01-23  0:00                       ` Travis Griggs
1997-01-23  0:00                       ` Tansel Ersavas
1997-01-24  0:00                     ` Fergus Henderson
1997-01-22  0:00                 ` Eric Clayberg
1997-01-23  0:00                   ` Don Harrison
1997-01-27  0:00                     ` John Woods
1997-01-28  0:00                       ` Alan Lovejoy
1997-01-23  0:00                   ` Combining dynamic and static typing Don Harrison
1997-01-24  0:00                     ` Erik M. Buck
     [not found]                       ` <01bc0b21$6a8293e0$7df2ad80@wkst01.milagro.austin.tx.us>
1997-01-25  0:00                         ` Nathan M. Urban
1997-01-28  0:00                           ` David L. Shang
1997-01-28  0:00                             ` Luther Hampton
1997-01-29  0:00                               ` Marc De Scheemaecker
1997-01-28  0:00                             ` Nathan M. Urban
1997-01-29  0:00                               ` David L. Shang
1997-01-29  0:00                               ` Russ McClelland
     [not found]                             ` <5d0efr$meb@news.xmission.com>
1997-02-09  0:00                               ` daniel damian burden
1997-01-27  0:00                     ` David L. Shang
1997-01-27  0:00                     ` Robert I. Eachus
1997-01-28  0:00                     ` Robert C. Martin
1997-01-29  0:00                       ` David L. Shang
1997-01-24  0:00                   ` OO, C++, and something much better! Andy Bower
1997-01-25  0:00                     ` Robert Dewar
1997-01-26  0:00                       ` Eric Clayberg
1997-01-26  0:00                         ` Robert Dewar
1997-01-26  0:00                         ` Robert Dewar
1997-01-25  0:00                     ` Robert Dewar
1997-01-26  0:00                       ` William Clodius
1997-01-27  0:00                   ` Robert C. Martin
1997-01-29  0:00                     ` Robert Dewar
1997-01-29  0:00                       ` Robert A Duff
1997-01-24  0:00             ` Tansel Ersavas
1997-01-25  0:00               ` Damon Feldman
1997-01-26  0:00                 ` Felix Beer
1997-01-28  0:00               ` Robert C. Martin
1997-01-28  0:00                 ` Matt Kennel
1997-01-29  0:00                 ` Del Archer
1997-01-24  0:00             ` Tansel Ersavas
1997-01-24  0:00             ` Tansel Ersavas
1997-01-25  0:00               ` Robert A Duff
1997-01-26  0:00                 ` Bob Haugen
1997-01-26  0:00                   ` Larry J. Elmore
1997-01-26  0:00                     ` Eric Clayberg
1997-01-26  0:00                   ` Robert Dewar
1997-01-26  0:00                     ` TanselErsavas
1997-01-27  0:00                     ` Samuel S. Shuster
1997-01-27  0:00                   ` David Hanley
1997-01-26  0:00                 ` Robert Dewar
1997-01-26  0:00                   ` James O'Connor
1997-01-26  0:00                     ` TanselErsavas
1997-01-26  0:00                       ` Robert Dewar
1997-01-27  0:00                         ` Eric Clayberg
1997-01-28  0:00                           ` Antoine Trux
1997-01-29  0:00                           ` Robert Dewar
1997-01-25  0:00               ` Fergus Henderson
1997-01-27  0:00             ` David Hanley
1997-01-28  0:00               ` OO, C++, and more and more useless arguments! Robert C. Martin
1997-01-28  0:00             ` OO, C++, and something much better! Alan Lovejoy
1997-01-28  0:00             ` Al Christians
1997-01-29  0:00             ` Alan Lovejoy
1997-02-21  0:00             ` Chris Bitmead
1997-02-21  0:00             ` Eric W. Nikitin
1997-02-21  0:00               ` Brian Rogoff
1997-02-24  0:00             ` Jon S Anthony
1997-02-24  0:00               ` Brian Rogoff
1997-02-25  0:00                 ` Eric W. Nikitin
1997-01-21  0:00           ` Norman H. Cohen
1997-01-22  0:00             ` Eric Clayberg
1997-01-23  0:00               ` Static vs. Dynamic typing again (was Re: OO, C++, and something much better!) Richie Bielak
1997-01-23  0:00                 ` Bill Gooch
1997-01-23  0:00                 ` Eric Clayberg
1997-01-23  0:00                   ` Richie Bielak
1997-01-24  0:00                     ` Eirik Mangseth
     [not found]                     ` <32E85588.1978@parcplace.com>
1997-01-26  0:00                       ` Paul Perkins
1997-01-26  0:00                         ` Robert A Duff
1997-01-29  0:00                           ` John Gale
1997-01-30  0:00                             ` Robert A Duff
1997-01-28  0:00                       ` Damon Feldman
1997-01-28  0:00                         ` Eric Clayberg
1997-01-23  0:00                   ` Richie Bielak
1997-01-23  0:00                     ` Rolf Breuning
1997-01-23  0:00                     ` Eric Clayberg
1997-01-24  0:00                       ` Richie Bielak
1997-01-24  0:00                         ` Bob Jarvis
1997-01-24  0:00                           ` Richie Bielak
1997-01-27  0:00                             ` Eric W. Nikitin
1997-01-25  0:00                           ` Robert A Duff
1997-01-30  0:00                             ` Damon Feldman
1997-01-30  0:00                               ` Fergus Henderson
1997-01-30  0:00                               ` Defintion, again, was Re: Static vs. Dynamic typing again David L. Shang
1997-01-30  0:00                               ` Static vs. Dynamic typing again (was Re: OO, C++, and something much better!) Robert A Duff
1997-02-09  0:00                               ` Piercarlo Grandi
1997-02-10  0:00                                 ` Matt Kennel
1997-02-14  0:00                                   ` Piercarlo Grandi
1997-01-24  0:00                       ` Robb Nebbe
1997-01-25  0:00                         ` OO, C++, and something much better! David N. Smith
1997-02-15  0:00                       ` Static vs. Dynamic typing again (was Re: OO, C++, and something much better!) Pieter Schoenmakers
1997-02-16  0:00                         ` Piercarlo Grandi
1997-01-27  0:00                     ` Jun Nolasco
1997-01-28  0:00                     ` Mark Windholtz
1997-01-28  0:00                       ` Richie Bielak
1997-01-28  0:00                 ` Alan Knight
1997-02-08  0:00                 ` Static vs. Dynamic typing again (was Re: OO, C++, and something mu Joachim Durchholz
1997-01-23  0:00               ` OO, C++, and something much better! Norman H. Cohen
1997-01-24  0:00                 ` Eric Clayberg
1997-01-27  0:00                   ` Norman H. Cohen
1997-01-28  0:00                     ` Tim Ottinger
1997-01-29  0:00                       ` Ted Dennison
1997-01-24  0:00                 ` traymond
1997-01-27  0:00                   ` Norman H. Cohen
1997-01-28  0:00                     ` traymond
1997-01-25  0:00                 ` Tansel Ersavas
1997-01-27  0:00                   ` Norman H. Cohen
1997-01-27  0:00                     ` Brian Rogoff
1997-01-28  0:00                       ` Reflection in Ada (was: Re: OO, C++, and something much better!) Norman H. Cohen
1997-01-29  0:00                         ` Eric W. Nikitin
1997-01-30  0:00                       ` OO, C++, and something much better! Tim Ottinger
1997-01-23  0:00             ` James O'Connor
1997-01-29  0:00               ` Stanley R. Allen
1997-01-30  0:00                 ` Robert A Duff
1997-01-27  0:00           ` Jon S Anthony
1997-01-19  0:00       ` Keith Thompson
1997-01-22  0:00     ` Don Harrison
1997-01-23  0:00       ` Robert I. Eachus
1997-01-23  0:00       ` Norman H. Cohen
1997-01-24  0:00         ` Don Harrison
1997-01-27  0:00           ` Norman H. Cohen
1997-01-29  0:00             ` "(Sub)type" -safety Don Harrison
1997-01-29  0:00               ` Jon S Anthony
1997-01-30  0:00                 ` Don Harrison
1997-01-20  0:00   ` OO, C++, and something much better! Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-01-24  0:00   ` Jon S Anthony
1997-01-26  0:00   ` Eric Clayberg
1997-01-27  0:00   ` Jon S Anthony
1997-01-27  0:00   ` Jon S Anthony
1997-01-27  0:00   ` Jon S Anthony
1997-01-28  0:00   ` Jon S Anthony
1997-01-29  0:00   ` Stephen J Bevan
1997-01-21  0:00 ` Joachim Durchholz
1997-01-22  0:00   ` Richard A. O'Keefe
1997-01-27  0:00     ` Robert A Duff
1997-01-27  0:00       ` Bob Jarvis
1997-01-28  0:00         ` Travis Griggs
1997-01-28  0:00       ` Norman H. Cohen
1997-01-28  0:00       ` Russ McClelland
1997-01-27  0:00     ` Robert Dewar
1997-01-27  0:00       ` Robert A Duff
1997-01-29  0:00         ` Robert Dewar
1997-01-27  0:00   ` John Woods
1997-01-22  0:00 ` Eric Clayberg
1997-01-23  0:00 ` Joachim Durchholz
1997-01-24  0:00 ` Joachim Durchholz
1997-01-29  0:00   ` Multiple Type Interfaces Joachim Durchholz
1997-01-25  0:00 ` OO, C++, and something much better! Eric Clayberg
1997-01-25  0:00 ` Tansel Ersavas
1997-01-25  0:00 ` James O'Connor
1997-01-26  0:00   ` Lawrence G. Mayka
1997-01-26  0:00     ` James O'Connor
1997-01-27  0:00 ` Norman H. Cohen
1997-02-07  0:00 ` Richard A. O'Keefe
1997-02-07  0:00   ` Alan Lovejoy
1997-02-12  0:00     ` Piercarlo Grandi
1997-02-13  0:00       ` Alan Lovejoy
     [not found]         ` <yf3ybcsm5ce.fsf@sabi.demon.co.uk>
1997-02-14  0:00           ` Alan Lovejoy
1997-02-16  0:00             ` Piercarlo Grandi
1997-02-16  0:00               ` Alan Lovejoy
1997-02-17  0:00                 ` Piercarlo Grandi
1997-02-13  0:00     ` Richard A. O'Keefe
1997-02-13  0:00       ` Alan Lovejoy
1997-02-18  0:00         ` Richard A. O'Keefe
1997-02-19  0:00           ` William Clodius
1997-02-19  0:00             ` Mike Klein
1997-02-19  0:00           ` Mike Klein
1997-02-19  0:00           ` richard
1997-02-15  0:00   ` Jon S Anthony
1997-02-16  0:00     ` Piercarlo Grandi
1997-02-16  0:00   ` Definition of "operator" (was: OO, C++, and something much better!) Alan Lovejoy
1997-02-19  0:00     ` Dave Schaumann
1997-02-19  0:00       ` Anders Pytte
1997-02-16  0:00   ` OO, C++, and something much better! Jon S Anthony
1997-02-18  0:00     ` Richard A. O'Keefe
1997-02-20  0:00       ` Matt Kennel
1997-02-20  0:00         ` Anders Pytte
1997-02-17  0:00   ` Jon S Anthony
1997-02-19  0:00     ` Piercarlo Grandi
1997-02-17  0:00   ` Definition of "operator" (was: OO, C++, and something much better!) Alan Lovejoy
1997-02-19  0:00     ` David L. Shang
1997-02-21  0:00     ` Jon S Anthony
1997-02-24  0:00       ` David L. Shang
1997-02-25  0:00       ` Jon S Anthony
1997-02-17  0:00   ` OO, C++, and something much better! Alan Lovejoy
1997-02-17  0:00   ` Jon S Anthony
1997-02-19  0:00     ` Piercarlo Grandi
1997-02-19  0:00       ` Mike Klein
1997-02-17  0:00   ` Jon S Anthony
1997-02-18  0:00   ` Bernard Badger
1997-02-18  0:00   ` Definition of "operator" (was: OO, C++, and something much better!) Jon S Anthony
1997-02-18  0:00   ` OO, C++, and something much better! Jon S Anthony
1997-02-19  0:00     ` Piercarlo Grandi
1997-02-19  0:00     ` Piercarlo Grandi
1997-02-21  0:00   ` Jon S Anthony
1997-02-24  0:00     ` Piercarlo Grandi
1997-02-22  0:00   ` Jon S Anthony
1997-02-22  0:00   ` Jon S Anthony
1997-02-22  0:00   ` Jon S Anthony
1997-02-22  0:00   ` Jon S Anthony
1997-02-25  0:00     ` Richard A. O'Keefe
1997-02-22  0:00   ` Jon S Anthony
1997-02-23  0:00   ` Definition of "operator" (was: OO, C++, and something much better!) Richard Katz
1997-02-24  0:00     ` David L. Shang
1997-02-25  0:00   ` OO, C++, and something much better! Jon S Anthony
1997-02-25  0:00   ` Jon S Anthony
1997-02-27  0:00     ` Clayton Weaver
1997-02-25  0:00   ` Jon S Anthony
1997-02-26  0:00   ` Mike Klein
1997-02-25  0:00 ` Jon S Anthony
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