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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,1b8bb636c4056425,start
X-Google-Attributes: gid103376,public
From: Scott Ingram <scott@silver.jhuapl.edu>
Subject: Using an array of variant records
Date: 2000/01/27
Message-ID: <389089CB.85F9FF72@silver.jhuapl.edu>#1/1
X-Deja-AN: 578403539
Content-Transfer-Encoding: 7bit
X-Accept-Language: en
Content-Type: text/plain; charset=us-ascii
X-Complaints-To: usenet@houston.jhuapl.edu
X-Trace: houston.jhuapl.edu 948996555 1344 128.244.80.107 (27 Jan 2000
 18:09:15 GMT)
Organization: Johns Hopkins University Applied Physics Lab, Laurel, MD, USA
Mime-Version: 1.0
NNTP-Posting-Date: 27 Jan 2000 18:09:15 GMT
Newsgroups: comp.lang.ada
Date: 2000-01-27T18:09:15+00:00
List-Id: <comp.lang.ada>

What I would like to do is to treat a set of variant records
as an array.  The discrimanant of the records is unconstrained,
but I seem unable to access it when trying to initialize the
record as element of an array.  The example below illustrates
what I want to accomplish, but gnat complains that it expects
a selector at the point that I want to select the discriminant.

Is it possible to do what I want?  

procedure snake_test is
   type snake is (garter, green);
   type snake_health is
      record
         Shed : Boolean;
         Active : Boolean;
   end record;
   type captive_snake (caged : Boolean := False) is
      record
        snake_kind : snake;
      case caged is
         when true =>
            health : snake_health;
         when others =>
            null;
      end case;
   end record;
   type snake_array is array (1..3) of captive_snake;
S1 : snake_array;
begin
   for i in 1..3 loop
      S1(i).(caged => True,
            snake_kind => green,
            health => (shed => true, active => true));
   end loop;
end snake_test;

Output from gnat:

Compiling: snake_test.adb (source file time stamp: 2000-01-27 18:07:28)
    22.       S1(i).(caged => True,
                    |
        >>> selector expected

Is there something that I have overlooked?  TIA,
-- 
Scott Ingram
Sonar Processing and Analysis Laboratory
Johns Hopkins University Applied Physics Laboratory