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=1.1 required=5.0 tests=BAYES_40,INVALID_DATE
	autolearn=no autolearn_force=no version=3.4.4
Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!tut.cis.ohio-state.edu!ucbvax!CRC.SKL.DND.CA!williams
From: williams@CRC.SKL.DND.CA (Dave Williamson)
Newsgroups: comp.lang.ada
Subject: Re: layering with discriminants
Message-ID: <9103051800.AA05744@crc.skl.dnd.ca>
Date: 5 Mar 91 18:00:43 GMT
Sender: usenet@ucbvax.BERKELEY.EDU
Organization: The Internet
List-Id: <comp.lang.ada>

In INFO-ADA Digest 91-39, David A. Hasan writes:

>GENERIC
>    TYPE size is (<>);
>PACKAGE g_lowLevel IS
>    TYPE adt (i : size) IS PRIVATE;

... lines deleted

>GENERIC
>    TYPE length is (<>);
>PACKAGE g_highLevel IS
>    TYPE adt (i : length) IS PRIVATE;
>PRIVATE
>    PACKAGE low_level IS NEW g_lowLevel(length);
>    TYPE adt (i : length) IS NEW low_level.adt(i);
>END g_highLevel;

Refer to LRM 3.7.1(3) - "A discriminant part is only allowed in the type
declaration for a record type, in a private type declaration or an incomplete
type declaration..."

I don't see anything there about derived types.  It appears that your
compiler was correct to reject, but may have led you down the garden path
with its message.

Dave Williamson
Software Kinetics Ltd.
Ottawa Ontario, Canada
williams@crc.skl.dnd.ca