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,d04a73d3b2c2dd0d
X-Google-Attributes: gid103376,public
From: jerry@jvdsys.nextjk.stuyts.nl (Jerry van Dijk)
Subject: Re: Q: Pointers to procedures/functions
Date: 1997/04/12
Message-ID: <860814408.18snx@jvdsys.nextjk.stuyts.nl>#1/1
X-Deja-AN: 234263624
Distribution: world
References: <1997Apr11.143821.5866@news>
Organization: *JerryWare HQ*, Haarlem, Holland
Newsgroups: comp.lang.ada
Date: 1997-04-12T00:00:00+00:00
List-Id: <comp.lang.ada>


>Is there a way to have pointers to procedures in Ada ?

Yes, see RM 3.10. Example:

   with Ada.Text_IO; use Ada.Text_IO;

   procedure Test is

      type Function_Call is access function (N : Integer) return Integer;

      function Double_It (N : Integer) return Integer is
      begin
         return 2 * N;
      end Double_It;

      function Triple_It (N : Integer) return Integer is
      begin
         return 3 * N;
      end Triple_It;

      procedure Display (N : in Integer; F : in Function_Call) is
      begin
         Put ("Calling function on value" & Integer'Image (N));
         Put (" results in" & Integer'Image (F (N)));
         New_Line;
      end Display;

   begin
      Display (4, Double_It'Access);
      Display (4, Triple_It'Access);
   end Test;

--

-- Jerry van Dijk       | Haarlem, Holland
-- Business Consultant  | Team Ada
-- Ordina Finance       | jdijk@acm.org