From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,8276b2994037cd71
X-Google-Attributes: gid103376,public
From: Lao Xiao Hai <laoxhai@ix.netcom.com>
Subject: Re: disjoint ranges ?
Date: 2000/10/16
Message-ID: <39EBB984.F2F8905F@ix.netcom.com>#1/1
X-Deja-AN: 682307756
Content-Transfer-Encoding: 7bit
References: <39E612C9.9BF98CD3@laas.fr> <DhpF5.178$AR3.40313@nnrp2.sbc.net>
 <8s59nu$ej4$1@news.huji.ac.il> <z6rF5.45$bz5.65618@nnrp3.sbc.net>
 <39E658A4.525AE881@acm.org> <39E6E890.3B13E7A9@laas.fr>
 <8s8iuk$q66$1@nnrp1.deja.com> <wcc66ms91t9.fsf@world.std.com>
X-Accept-Language: en
X-Server-Date: 17 Oct 2000 02:34:55 GMT
Content-Type: text/plain; charset=us-ascii
Organization: MindSpring Enterprises
Mime-Version: 1.0
Newsgroups: comp.lang.ada
Date: 2000-10-17T02:34:55+00:00
List-Id: <comp.lang.ada>



Robert A Duff wrote:

> Robert Dewar <robert_dewar@my-deja.com> writes:
>
> > No, it could be over all damaging. Every new feature you add
> > to a language damages it by adding to the understanding,
> > programming, description, and implementation complexity.
>
> Quite true, but you don't necessarily have to add features in order to
> add functionality.  Sometimes, making a feature more powerful can add
> functionality without increasing complexity.

So, making a feature more powerful might be something such as being
able to overload the "in" membership test.   For some reason, this
operator is not really a first class operator in Ada.   I have often
wondered about the rationale for that decision.    If it were overloadable,

one could simply declare a membership function that would enable
disjoint membership tests.

I do see some problems with this when considered in terms of the
for loop since it would be a strange loop, indeed, that had disjoint
values.  On the other hand, that could also be an alternate solution
to the absence of a step capability.   Also, it does not have to
be incompatible with the requirement that the value be discrete.

Any thoughts on this?

Richard Riehle