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From: bobduff@world.std.com (Robert A Duff)
Subject: Re: Equality operator overloading in ADA 83
Date: 1997/04/23
Date: 1997-04-23T00:00:00+00:00	[thread overview]
Message-ID: <E93v4u.DG1@world.std.com> (raw)
In-Reply-To: 335E0B1F.12C9@elca-matrix.ch


In article <335E0B1F.12C9@elca-matrix.ch>,
Mats Weber  <Mats.Weber@elca-matrix.ch> wrote:
>> Composability should always be guaranteed by user-defined types, too.
>
>There seems to be much disagreement on this question for all kinds of
>reasons. But I agree with you 100%.

I think I agree that "=" should compose, in the sense that composite
types call the user-defined "=" of their components, and the predefined
"=" doesn't "re-emerge" in generics.  But how far do you think we should
carry this?  E.g. if "=" is redefined for a scalar type, does that
affect case statements on that type?  After all, case stms check the
case expression for equality with some values.  What about operators
other than "="?  If "/" is redefined for an integer type, should
Text_IO.Integer_IO know about it?  It might well make Put(some-integer)
do the "wrong" thing, since the generic might need to divide by 10.

If I redefine "<" on a scalar type, should "<" on an array-of-that-type
call it?

- Bob




  reply	other threads:[~1997-04-23  0:00 UTC|newest]

Thread overview: 114+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-04-21  0:00 Equality operator overloading in ADA 83 Manuel Wenger
1997-04-22  0:00 ` Mats Weber
1997-04-22  0:00 ` Matthew Heaney
1997-04-22  0:00   ` Philip Brashear
1997-04-22  0:00   ` Mats Weber
1997-04-22  0:00     ` Robert A Duff
1997-04-22  0:00       ` Matthew Heaney
1997-04-23  0:00         ` Mats Weber
1997-04-23  0:00           ` Robert A Duff [this message]
1997-04-24  0:00             ` Mats Weber
1997-04-24  0:00               ` Matthew Heaney
1997-04-25  0:00                 ` Robert Dewar
1997-04-25  0:00                   ` Matthew Heaney
1997-04-26  0:00                     ` Robert Dewar
1997-04-26  0:00                     ` Robert A Duff
1997-04-25  0:00                 ` Robert Dewar
1997-04-25  0:00                   ` Matthew Heaney
1997-04-26  0:00                     ` Robert Dewar
1997-04-26  0:00                   ` Fergus Henderson
1997-04-26  0:00                     ` Robert A Duff
1997-04-26  0:00                       ` Robert Dewar
1997-04-27  0:00                     ` Robert Dewar
1997-04-24  0:00               ` Robert A Duff
1997-04-24  0:00                 ` Robert Dewar
1997-04-25  0:00                   ` Robert A Duff
1997-04-26  0:00                     ` Nick Roberts
1997-04-26  0:00                       ` Robert Dewar
1997-04-26  0:00                         ` Matthew Heaney
1997-05-02  0:00                           ` Nick Roberts
1997-05-04  0:00                             ` Robert Dewar
1997-05-05  0:00                               ` Mats Weber
1997-05-05  0:00                                 ` Robert Dewar
1997-05-06  0:00                                   ` Matthew Heaney
1997-05-06  0:00                                     ` Robert Dewar
1997-05-07  0:00                                     ` Tucker Taft
1997-05-05  0:00                               ` Robert A Duff
1997-04-26  0:00                       ` Robert A Duff
1997-04-26  0:00                         ` Robert Dewar
1997-04-27  0:00                           ` Robert A Duff
1997-04-26  0:00                             ` Robert Dewar
1997-04-28  0:00                               ` Simon Wright
1997-04-29  0:00                                 ` Robert I. Eachus
1997-04-29  0:00                       ` Mats Weber
1997-05-01  0:00                         ` Robert Dewar
     [not found]                           ` <01bc571c$01f3ffc0$5de2b8cd@p5120.bda>
1997-05-03  0:00                             ` Robert Dewar
1997-04-27  0:00                     ` Robert Dewar
1997-04-27  0:00                       ` Fergus Henderson
1997-04-27  0:00                         ` Robert Dewar
1997-04-28  0:00                           ` Fergus Henderson
1997-04-28  0:00                             ` Robert Dewar
1997-04-25  0:00                 ` Kevin Cline
1997-04-25  0:00                   ` Robert A Duff
1997-04-25  0:00                   ` Mats Weber
1997-04-25  0:00                     ` Robert Dewar
1997-04-29  0:00                       ` Mats Weber
1997-05-01  0:00                         ` Robert Dewar
1997-04-25  0:00                   ` Mats Weber
1997-04-27  0:00                     ` Robert Dewar
1997-04-29  0:00                       ` Mats Weber
1997-04-25  0:00                 ` Mats Weber
1997-04-27  0:00                 ` Geert Bosch
1997-04-28  0:00               ` Robert Dewar
1997-04-29  0:00                 ` Mats Weber
1997-04-29  0:00                   ` Robert A Duff
1997-04-29  0:00                     ` Matthew Heaney
1997-05-02  0:00                       ` Tucker Taft
1997-05-02  0:00                         ` Robert Dewar
1997-05-02  0:00                           ` Robert A Duff
1997-05-03  0:00                             ` Robert Dewar
1997-05-01  0:00                   ` Robert Dewar
1997-04-29  0:00                 ` Matthew Heaney
1997-05-01  0:00                   ` Robert Dewar
1997-04-28  0:00               ` Robert Dewar
1997-04-23  0:00           ` Robert Dewar
1997-04-24  0:00             ` Robert A Duff
1997-04-29  0:00             ` Mats Weber
1997-05-01  0:00               ` Robert Dewar
1997-04-24  0:00         ` Robert Dewar
1997-04-22  0:00       ` Mats Weber
1997-04-22  0:00     ` Matthew Heaney
1997-04-23  0:00       ` Mats Weber
1997-04-23  0:00         ` Robert A Duff
1997-04-25  0:00           ` Kevin Cline
1997-04-25  0:00             ` Robert A Duff
1997-04-25  0:00             ` Matthew Heaney
1997-04-25  0:00               ` Robert A Duff
1997-04-25  0:00                 ` Jon S Anthony
1997-04-27  0:00                   ` Robert Dewar
1997-04-28  0:00                   ` Robert I. Eachus
1997-04-29  0:00                     ` Jon S Anthony
1997-04-26  0:00               ` Robert Dewar
1997-04-27  0:00                 ` Matthew Heaney
1997-04-27  0:00                   ` Robert A Duff
1997-04-26  0:00             ` Robert Dewar
1997-04-26  0:00               ` Matthew Heaney
1997-04-24  0:00     ` Robert Dewar
1997-04-24  0:00       ` Robert A Duff
1997-04-25  0:00         ` Robert Dewar
1997-04-25  0:00           ` Matthew Heaney
1997-04-26  0:00             ` Robert Dewar
1997-04-26  0:00               ` Robert A Duff
1997-04-26  0:00                 ` Robert Dewar
1997-04-26  0:00                   ` Matthew Heaney
1997-04-27  0:00                   ` Robert A Duff
1997-04-26  0:00                 ` Robert Dewar
1997-04-26  0:00                   ` Matthew Heaney
1997-04-27  0:00                     ` Robert Dewar
1997-04-27  0:00                   ` Robert A Duff
1997-04-26  0:00                     ` Robert Dewar
1997-05-02  0:00                       ` Nick Roberts
1997-05-04  0:00                         ` Robert Dewar
1997-04-22  0:00 ` Kevin Cline
1997-04-22  0:00   ` Mark A Biggar
1997-04-24  0:00   ` Keith Thompson
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