From: "Nick Roberts" <nickroberts@adaos.worldonline.co.uk>
Subject: Re: Overridability of _private_ predefined "=" [was Re: list strawman]
Date: Sat, 19 Jan 2002 22:42:29 -0000
Date: 2002-01-19T22:42:29+00:00 [thread overview]
Message-ID: <a2ct8p$visv7$1@ID-25716.news.dfncis.de> (raw)
In-Reply-To: 3C49A5C4.51D6@li.net
"Vincent Marciante" <marciant_remove@li.net> wrote in message
news:3C49A5C4.51D6@li.net...
> ...
> This is why I find the situation to be so bad now. A generic written
> for Ada 83 that only imports a private type can not be made into a valid
> Ada 95 one by simply transforming its spec by adding the importation of
> "=" for that type; Its body must also be analyzed and possibly changed
> so as to use componant by componant comparison for any composite types
> having the private type as a componant (or predefined "=" has to be
> overridden for those composite types _and_ any other composite types the
> have those composite types as componants.)
>
> What was impossible (?) to do wrong in Ada 83 has now become a pitfall
> in Ada 95. were by we have to dilligently follow the verbal guideline
> that you just suggested.
AI-123 discusses this in some detail, and results (rev 12) in a corrigendum
which specifically compels language-defined types to be composable with
respect to equality (thus forcing them to be implemented either without
redefined equality or as tagged types). I smell a hint of hypocrisy here.
Personally, I completely agree with Vincent. Damn Ada 83 compatibility, and
damn implementation complexities: equality should always be composable; the
current state is plainly a potential source of 'nasty surprises'; the
language is purportedly supposed to avoid nasty surprises. But I am a small
voice.
--
Best wishes,
Nick Roberts
next prev parent reply other threads:[~2002-01-19 22:42 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-01-06 20:55 list strawman Stephen Leake
2002-01-07 15:56 ` Ted Dennison
2002-01-07 15:57 ` Ted Dennison
2002-01-07 16:33 ` Stephen Leake
2002-01-07 16:37 ` Stephen Leake
2002-01-07 19:31 ` Ted Dennison
2002-01-07 19:26 ` Ted Dennison
2002-01-07 22:05 ` Stephen Leake
2002-01-07 22:51 ` Ted Dennison
2002-01-08 0:48 ` Steven Deller
2002-01-08 15:32 ` Ted Dennison
2002-01-08 15:43 ` Jean-Marc Bourguet
2002-01-08 17:07 ` Ted Dennison
2002-01-08 17:21 ` Jean-Marc Bourguet
2002-01-08 19:12 ` Ted Dennison
2002-01-09 8:09 ` Jean-Marc Bourguet
2002-01-09 18:37 ` Ted Dennison
2002-01-11 9:37 ` Jean-Marc Bourguet
2002-01-11 17:03 ` Ted Dennison
2002-01-11 17:47 ` Jeffrey Carter
2002-01-12 15:10 ` Jean-Marc Bourguet
2002-01-13 10:18 ` Jean-Marc Bourguet
2002-01-14 16:02 ` Ted Dennison
2002-01-14 16:22 ` Jean-Marc Bourguet
2002-01-08 19:57 ` Steven Deller
2002-01-08 19:54 ` Steven Deller
2002-01-08 19:54 ` Steven Deller
2002-01-08 20:46 ` Ted Dennison
2002-01-08 21:21 ` Stephen Leake
2002-01-08 21:49 ` Ted Dennison
2002-01-09 9:21 ` Thomas Wolf
2002-01-09 15:20 ` Ted Dennison
2002-01-09 15:53 ` Stephen Leake
2002-01-09 21:21 ` Ted Dennison
2002-01-09 17:42 ` Mark Lundquist
2002-01-09 21:02 ` Jeffrey Carter
2002-01-10 8:47 ` Thomas Wolf
2002-01-11 17:38 ` Jeffrey Carter
2002-01-11 21:52 ` Chad Robert Meiners
2002-01-12 5:45 ` Jeffrey Carter
2002-01-12 22:20 ` Chad R. Meiners
2002-01-13 17:03 ` Jeffrey Carter
2002-01-13 23:47 ` Chad R. Meiners
2002-01-14 1:32 ` Ted Dennison
2002-01-14 5:12 ` Jeffrey Carter
2002-01-14 5:12 ` Jeffrey Carter
2002-01-10 14:39 ` Ted Dennison
2002-01-11 5:34 ` Mark Biggar
2002-01-12 12:20 ` Simon Wright
2002-01-14 14:53 ` Matthew Heaney
2002-01-16 5:56 ` Simon Wright
2002-01-18 9:15 ` Overridability of _private_ predefined "=" [was Re: list strawman] Vincent Marciante
2002-01-19 16:58 ` Vincent Marciante
2002-01-19 22:42 ` Nick Roberts [this message]
2002-01-09 3:10 ` list strawman Ted Dennison
2002-01-09 19:09 ` Ted Dennison
2002-01-08 21:26 ` Georg Bauhaus
2002-01-08 22:13 ` Ted Dennison
2002-01-09 20:52 ` Jeffrey Carter
2002-02-17 15:04 ` Florian Weimer
2002-02-17 15:05 ` Florian Weimer
2002-02-18 1:43 ` Stephen Leake
2002-02-18 8:57 ` Florian Weimer
-- strict thread matches above, loose matches on Subject: below --
2002-01-18 10:43 Overridability of _private_ predefined "=" [was Re: list strawman] Christoph Grein
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