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From: bobduff@world.std.com (Robert A Duff)
Subject: Re: Equality operator overloading in ADA 83
Date: 1997/04/29
Message-ID: <E9EKDn.77q@world.std.com>#1/1
X-Deja-AN: 238156188
References: <01bc4e9b$ac0e7fa0$72041dc2@lightning>
 <335F5971.6375@elca-matrix.ch> <dewar.862275693@merv>
 <3365D08F.26EA@elca-matrix.ch>
Organization: The World Public Access UNIX, Brookline, MA
Newsgroups: comp.lang.ada
Date: 1997-04-29T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <3365D08F.26EA@elca-matrix.ch>,
Mats Weber  <Mats.Weber@elca-matrix.ch> wrote:
>The difference in behavior between tagged and non-tagged types,
>especially in the case where a type is not visibly tagged, is
>particularly ugly IMO.

In retrospect, I tend to agree that we should have gone a wee bit
further in composability of "=".  Especially since "=" on nonlimited
types is a new feature (except for the Goodenough trick, which is silly
to worry about).  And because "=" is already special anyway -- the magic
"/=" you get for free, the fact that dispatching calls to "=" do a
different sort of tag check, etc.

However, I'm not quite sure how far we should have gone.  Not very.
Certainly not to extending composability to other operators, and
certainly not affecting the semantics of "in" or "case".  Perhaps I'd
consider such things for a new language, but not for Ada 9X.

- Bob