comp.lang.ada
 help / color / mirror / Atom feed
From: "Ed Falis" <falis@verizon.net>
Subject: Re: types and subtypes
Date: Mon, 13 Mar 2006 18:17:21 GMT
Date: 2006-03-13T18:17:21+00:00	[thread overview]
Message-ID: <op.s6c6evlk5afhvo@dogen> (raw)
In-Reply-To: 1142273325.634632.41020@j52g2000cwj.googlegroups.com

On Mon, 13 Mar 2006 13:08:45 -0500, <ada_student@yahoo.com> wrote:

> Why was Ada's subtyping defined to exclude derivation?

Derived types in Ada, whether tagged or not, are the same as the  
conventional usage of the term "subtype" in other OO languages.  Subtypes  
in Ada are about adding constraints on the range of acceptable values,  
rather than emphasizing type extension and overriding of subprograms,  
which is the role of a derived type.

Ada's use of the term "subtype" preceded the development of most OO  
languages (Simula 67 being a noteworthy exception, and probably Smalltalk).

- Ed



  reply	other threads:[~2006-03-13 18:17 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-03-13 12:07 types and subtypes ada_student
2006-03-13 13:20 ` Jean-Pierre Rosen
2006-03-13 18:08   ` ada_student
2006-03-13 18:17     ` Ed Falis [this message]
2006-03-13 19:14     ` Larry Kilgallen
2006-03-13 19:42     ` Martin Krischik
2006-03-13 20:22     ` Wilhelm Spickermann
2006-03-14  8:47     ` Dmitry A. Kazakov
2006-03-14 14:39     ` Jean-Pierre Rosen
2006-03-17  1:24     ` Peter C. Chapin
replies disabled

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