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=-2.9 required=5.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,9d303864ae4c70ad X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2004-04-07 17:11:12 PST Path: archiver1.google.com!news1.google.com!news.glorb.com!news.cs.univ-paris8.fr!proxad.net!usenet-fr.net!enst.fr!melchior!cuivre.fr.eu.org!melchior.frmug.org!not-for-mail From: "Alexander E. Kopilovich" Newsgroups: comp.lang.ada Subject: Re: Reprise: 'in out' parameters for functions Date: Thu, 8 Apr 2004 03:54:11 +0400 (MSD) Organization: Cuivre, Argent, Or Message-ID: References: NNTP-Posting-Host: lovelace.ada-france.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: melchior.cuivre.fr.eu.org 1081382438 72123 212.85.156.195 (8 Apr 2004 00:00:38 GMT) X-Complaints-To: usenet@melchior.cuivre.fr.eu.org NNTP-Posting-Date: Thu, 8 Apr 2004 00:00:38 +0000 (UTC) To: comp.lang.ada@ada-france.org Return-Path: In-Reply-To: ; from Stephen Leake at 07 Apr 2004 16:31:44 -0400 X-Mailer: Mail/@ [v2.44 MSDOS] X-Virus-Scanned: by amavisd-new-20030616-p7 (Debian) at ada-france.org X-BeenThere: comp.lang.ada@ada-france.org X-Mailman-Version: 2.1.4 Precedence: list List-Id: "Gateway to the comp.lang.ada Usenet newsgroup" List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Xref: archiver1.google.com comp.lang.ada:6827 Date: 2004-04-08T03:54:11+04:00 Stephen Leake wrote: > I just ran across a need for an 'in out' parameter in a function, in > "real code", so I thought I post it here "just for fun" :). > > This is what I wanted to declare: > > function Parse > (Error_Label : in String; > Token : in out Token_List.List_Iterator) > return String; > -- Process Token, which should contain '([Config_File =>] )'. > -- Return the string. > -- Delete parsed tokens from Token. > > Token must be 'in out', because the next parse function called wants > to work on the stuff after the config file. > > Parse must be a function, because I'm returning a String. > > The work-around is to use a procedure and a bounded string: > > procedure Parse > (Error_Label : in String; > Token : in out Token_List.List_Iterator; > Config_File_Name : out OpenToken.Buffers.Bounded_String); > > In this instance, the body of Parse deals with > OpenToken.Buffers.Bounded_String anyway, so there's no actual new > overhead introduced. But the user interface is not as clean as it > could be. One thing is missing in this your explanation: why exactly you don't want to make that List_Iterator global (instead of passing it as IN OUT argument) ? Alexander Kopilovitch aek@vib.usr.pu.ru Saint-Petersburg Russia