From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.5-pre1 (2020-06-20) on
	ip-172-31-74-118.ec2.internal
X-Spam-Level: 
X-Spam-Status: No, score=-0.9 required=3.0 tests=BAYES_00,FROM_ADDR_WS
	autolearn=no autolearn_force=no version=3.4.5-pre1
Date: 21 Sep 92 17:26:52 GMT
From: haven.umd.edu!darwin.sura.net!cs.ucf.edu!crigler@ames.arc.nasa.gov  (Jame
s Crigler)
Subject: Re: Pascal type sets in Ada?
Message-ID: <1992Sep21.172652.951@cs.ucf.edu>
List-Id: <comp.lang.ada>

In article <1992Sep21.050905.1@cc.utah.edu> eyring@cc.utah.edu writes:
>This is a question I have had for some time.
>Why doesn't Ada include Pascal type sets?
>There must be a reason.  Or how does one 
>do Pascal sets in Ada?  Any ideas?
>-- 
>>Bob Witmer

I think Booch discusses this (or something simalar) in _Software_Engineering_
In_Ada (my least favorite Ada book).  The essence is to create a generic
that defines a set to be a BOOLEAN array, then use pragma PACK to lower the
space overhead.

E. g.:

generic
  type BASE is (<>);
package SET_PKG is 
  type SET_TYPE is array (BASE) of BOOLEAN;
  pragma PACK (SET_TYPE);
  function "+" (S : SET_TYPE; I : BASE) return SET_TYPE;  -- Add a member
  function "-" (S : SET_TYPE; I : BASE) return SET_TYPE;  -- Remove a member
  function IS_A_SUBSET (S : SET_TYPE; POTENTIAL : SET_TYPE) return BOOLEAN;
  function IS_A_MEMBER (S : SET_TYPE; I : BASE) return BOOLEAN;
  ...
end SET_PKG;

Jim Crigler
----------------------------------------
Guinan is Q's mother.