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=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD,
	FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4
X-Google-Thread: 103376,86c750b8474bf6d5
X-Google-Attributes: gid103376,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news3.google.com!news.germany.com!news.motzarella.org!motzarella.org!not-for-mail
From: Sebastien Morand <seb.morand@gmail.com>
Newsgroups: comp.lang.ada
Subject: Re: About String
Date: Sun, 08 Jun 2008 19:03:17 +0000
Organization: A noiseless patient Spider
Message-ID: <484C2CF5.6060309@gmail.com>
References: <g2bs6b$h2m$1@registered.motzarella.org> <m2od6d5id7.fsf@mac.com>
 <484ABED3.8040909@obry.net> <m2fxro5gcx.fsf@mac.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Trace: feeder.motzarella.org
 U2FsdGVkX1/daIOwrYNn2v/1R2TVjpEhZBvcbSK2j7WmTlqlnn5vQSSQ4QbeaiHAS/608ZQWEzjj/9fggbhArC1CSvG0Ovfc9yEE2p487VXBDqQccf0L8vv21rrkArKzXkCoSIYxR7U=
X-Complaints-To: Please send complaints to abuse@motzarella.org with full
 headers
NNTP-Posting-Date: Sun, 8 Jun 2008 19:00:07 +0000 (UTC)
In-Reply-To: 
X-Auth-Sender: U2FsdGVkX19AhPFJtiqIrFgPl8t3H1OTAysR9aoiYNg=
Cancel-Lock: sha1:l+Xx3odhmSUP+YuDyXf2FPdFjY0=
User-Agent: Thunderbird 2.0.0.12 (X11/20080406)
Xref: g2news1.google.com comp.lang.ada:618
Date: 2008-06-08T19:03:17+00:00
List-Id: <comp.lang.ada>

> I meant to say
> 
>    procedure Patati_Patata is
>    begin
>       begin
>          declare
>             S : String := A_Function_Raising_Constraint_Error;
>          begin
>             --  some code
>          end;
>       exception
>          when Constraint_Error =>
>             --  deal with the problem ..
>       end;
>       --  .. and carry on
>    end;

And it's what exactly I don't think pretty nice and easy to maintain. Other 
solution proposed by previous post is to separate the code with nested function:

procedure Patati_Patata is

    function Manage_S return String;

    function Manage_S return String is
    begin
       declare
          S : String := A_Function_Raising_Constraint_Error;
       begin
          --  some code
          return S;
       end;
    exception
       when Constraint_Error =>
          --  deal with the problem ..
          return ""; --  Or something else to manage the error but something 
must be returned to be consistent
    end;

    S: String := Manage_S;

begin
    --  .. and carry on
end;

I think it's a better way especially because:
1) You can put away the nested function (for instance as a private package function)
2) You can reuse the function
3) You string are constant most of time (meaning: "S: constant String := Manage_S;")

The only disadvantage for me is that you write a lot little function if you use 
a lot of string (and frankly, you always do in high level application).

I wonder too if there is a nice way to manipulate string using access type. I 
don't choose to try this way because I think it's the better way to introduce 
some memory link.

Sebastien