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,XPRIO autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,19c9b8adc049bc94,start
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
From: "quasar" <quasar@nospam.com>
Newsgroups: comp.lang.ada
Subject: handling null pointers/records to functions
Date: Sat, 21 Aug 2004 22:59:27 +1000
Organization: -
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.2180
X-RFC2646: Format=Flowed; Original
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180
NNTP-Posting-Host: 220.244.246.241
X-Original-NNTP-Posting-Host: 220.244.246.241
Message-ID: <41274733@dnews.tpgi.com.au>
X-Trace: dnews.tpgi.com.au!tpg.com.au 1093093171 220.244.246.241 (21 Aug 2004
 22:59:31 +1000)
Path: 
 g2news1.google.com!news2.google.com!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.freenet.de!solnet.ch!solnet.ch!nntp.gblx.net!nntp3.phx1!dnews.tpgi.com.au!tpg.com.au!not-for-mail
Xref: g2news1.google.com comp.lang.ada:2909
Date: 2004-08-21T22:59:27+10:00
List-Id: <comp.lang.ada>

Hi , I was wondering what is the best way to handle null records/pointers 
passed to functions with a return type that is generic?

for example in this snippet of code node_ptr_type is a record holding a 
single data value of type Data_Type

function Data_Part (Node_Ptr : Node_Ptr_Type ) return Data_Type is
begin
    if node_ptr /= null then
        return Node_Ptr.Data;
    else
        Put_Line("Node passed to FUNCTION DATA_PART is null");
        {(**)at this point i do not know what to do... do I terminate the 
program, do I return some form of null object}
    end if;
end Data_Part;

What is the most recommended way to handle this? Point (**) has got me 
stuck.

Thanks any help would be great
quasar