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=-0.3 required=5.0 tests=BAYES_00,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
X-Google-Thread: a07f3367d7,b85c1b84f840dc22
X-Google-Attributes: gida07f3367d7,public,usenet
X-Google-NewGroupId: yes
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news4.google.com!feeder.news-service.com!newsfeed101.telia.com!nf02.dk.telia.net!news.tele.dk!news.tele.dk!small.news.tele.dk!bnewspeer01.bru.ops.eu.uu.net!bnewspeer00.bru.ops.eu.uu.net!emea.uu.net!newsfeed.arcor.de!newsspool2.arcor-online.net!news.arcor.de.POSTED!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: I need a little help - it's been a long time - with enumeration
 type  and for use representation
Newsgroups: comp.lang.ada
User-Agent: 40tude_Dialog/2.0.15.1
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Reply-To: mailbox@dmitry-kazakov.de
Organization: cbb software GmbH
References: <7495d29e-0361-4eba-9e22-a770ae50f113@d5g2000yqm.googlegroups.com>
 <uj01w89h0yfz$.49he8yac790e$.dlg@40tude.net>
 <hdk9hp$qmn$2@news.tornevall.net>
 <psedux1zazm0$.1eqnd82wubisd$.dlg@40tude.net>
 <hdkfm2$u10$1@news.tornevall.net>
Date: Fri, 13 Nov 2009 21:53:15 +0100
Message-ID: <1hgihvw2ld2nr.cg5ve3xaww03.dlg@40tude.net>
NNTP-Posting-Date: 13 Nov 2009 21:53:16 CET
NNTP-Posting-Host: 2d0d8655.newsspool3.arcor-online.net
X-Trace: 
 DXC=ZUi9S]mUh^=gP]QSEBQ^d4McF=Q^Z^V384Fo<]lROoR18kF<OcfhCO;kGE>o`eP>L5[6LHn;2LCV>[<mhadbfdU;Q86og[U5_J2VJdPJ>CX3?2
X-Complaints-To: usenet-abuse@arcor.de
Xref: g2news1.google.com comp.lang.ada:8098
Date: 2009-11-13T21:53:16+01:00
List-Id: <comp.lang.ada>

On Fri, 13 Nov 2009 13:32:52 -0700, Jeffrey R. Carter wrote:

> Dmitry A. Kazakov wrote:
>> On Fri, 13 Nov 2009 11:48:12 -0700, Jeffrey R. Carter wrote:
>> 
>>> Dmitry A. Kazakov wrote:
>>>> You parse "0x", then you do a hexadecimal number following it, then you
>>>> pass that number (x) to:
>>>>
>>>>    Spell_School_Type'Val (x)
>>> This doesn't work with a non-default representation. 'Val reverses 'Pos, and 
>>> 'Pos gives sequential values starting with zero, regardless of the representation.
>> 
>> But it works with the modular type proposed. An enumeration type was not
>> meant. For enumeration types one should parse names, rather than arbitrary
>> bit patterns.
> 
> I see. I cannot imagine using 'Val in this case. Since you start with a String 
> containing the hexadecimal image of a value, I'd simply do
> 
> Numeric_Type_Name'Value ("16#" & Source (Start .. Stop) & '#');

I do it differently. I have the pattern:

procedure Get (Text : String; Pointer : in out Integer; Value : out Type)

which I consistently deploy everywhere. Get takes a textual representation
of Type from Text at Pointer and advances Pointer to the first position
following it. The result is returned though Value.

However, yes, usually I use a plain type conversion:

   Get (Text, Pointer, Integer (Value));

rather than Type'Val (when I am too lazy to instantiate the generic
packages once again with Type)

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de