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,FREEMAIL_FROM,XPRIO
	autolearn=ham autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,ec7ccf8eee6d37fc,start
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2001-06-16 10:31:21 PST
Path: 
 archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!news.tele.dk!130.133.1.3!fu-berlin.de!uni-berlin.de!cmnz-3e36fc21.pool.mediaways.NET!not-for-mail
From: "Thomas Nebel" <thomas_nebel@gmx.de>
Newsgroups: comp.lang.ada
Subject: virtual functions in ada95
Date: Sat, 16 Jun 2001 19:31:07 +0200
Message-ID: <9gg557$8sgga$1@ID-42131.news.dfncis.de>
NNTP-Posting-Host: cmnz-3e36fc21.pool.mediaways.net (62.54.252.33)
X-Trace: fu-berlin.de 992712679 9323018 62.54.252.33 (16 [42131])
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.00.2919.6700
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6700
Xref: archiver1.google.com comp.lang.ada:8805
Date: 2001-06-16T19:31:07+02:00
List-Id: <comp.lang.ada>

Hi

How can i use virtual functions in Ada? I have a superclass and some classes
that are derived
from it:

type TNTGL_Custom_Node_Record is tagged null record;
type TNTGL_Node_Record is new TNTGL_Custom_Node_Record with private;
type TNTGL_Visual_Node_Record is new TNTGL_Node_Record with private;
type TNTGL_Sphere_Record is new TNTGL_Visual_Node_Record with private;

type TNTGL_Node is access all TNTGL_Node_Record'Class;
type TNTGL_Sphere is access all TNTGL_Sphere_Record'Class;
....
procedure Run (Node : access TNTGL_Node_Record'Class);
procedure Run (Node : access TNTGL_Group_Node_Record'Class);
procedure Run (Sphere : access TNTGL_Sphere_Record'Class);

Now i want to "run" the classes from one point transparently :

Node : TNTGL_Node;
...
Node := Scene.First_Node;
while Node /= null loop
    Run (Node);
    Node := Get_Next (Node);
end loop;

Independent of the real type of the Node variable, the Run function is
always the Run from
TNTGL_Node_Record.

How can i manage it, that the Run function for the real Node type is called
?

Thomas