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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,38b27bed88e97415
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2003-02-20 12:37:26 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!nntp-relay.ihug.net!ihug.co.nz!west.cox.net!cox.net!newsfeed1.earthlink.net!newsfeed.earthlink.net!stamper.news.pas.earthlink.net!newsread1.prod.itd.earthlink.net.POSTED!not-for-mail
Message-ID: <3E553C5E.7B2850FD@tsoft.com>
From: Yuri <yuri@tsoft.com>
X-Mailer: Mozilla 4.79 [en] (X11; U; Linux 2.4.2 i386)
X-Accept-Language: en
MIME-Version: 1.0
Newsgroups: comp.lang.ada
Subject: Re: Question: Combination of Access and Constraining
References: <1d13e1b4.0302200006.70207b86@posting.google.com>
 <9d795v0h3qa2922u8vodfhpfvprpre6ak2@4ax.com>
 <1d13e1b4.0302200720.9666350@posting.google.com> <3E5517AE.1040003@acm.org>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Date: Thu, 20 Feb 2003 20:35:52 GMT
NNTP-Posting-Host: 65.59.72.131
X-Complaints-To: abuse@earthlink.net
X-Trace: newsread1.prod.itd.earthlink.net 1045773352 65.59.72.131 (Thu,
 20 Feb 2003 12:35:52 PST)
NNTP-Posting-Date: Thu, 20 Feb 2003 12:35:52 PST
Organization: EarthLink Inc. -- http://www.EarthLink.net
Xref: archiver1.google.com comp.lang.ada:34301
Date: 2003-02-20T20:35:52+00:00
List-Id: <comp.lang.ada>

Jeffrey Carter wrote:

> >>function Fn (Arg : Tp) return Natural;
> >
> > I have to use access type here. Since this is
> > simplified example. I have function accepting
> > several such array arguments each of which is
> > optional (null).
>
> This is still not a requirement to use access types. You can still say
>
> Null_Tp : constant Tp (1 .. 0) := (1 .. 0 => False);
>
> function Fn (Arg1 : Tp := Null_Tp; Arg2 : Tp := Null_Tp; ...)
> return Natural;
>
> Here you have a function with several such array arguments, each of
> which is optional, and each of which is a null array if not explicitly
> specified:
>
> Tp1 : Tp (1 ..    10) := ...;
> Tp2 : Tp (1 .. 1_000) := ...;
> X   : Natural;
> ...
> X := Fn (Tp1);         -- All except Arg1 are null
> X := Fn (Arg2 => Tp2); -- All except Arg2 are null
> X := Fn (Tp2, Tp1);    -- All except Arg1 & Arg2 are null

And how efficient will be eventual comparison/argument
passing code resulting from such Null_Tp constant? Is it going to be
one-instruction comparison in ASM or much more?

For access argument and null it probably will be just on-liner
comparison and one liner passing argument.

Just curious )

Yuri.