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From: Stephen Bleasdale <sd@eateggs.demon.co.uk>
Subject: Callback procedures in DEC Ada83
Date: 1997/05/18
Message-ID: <682.7077T710T120@eateggs.demon.co.uk>#1/1
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Newsgroups: comp.lang.ada
Date: 1997-05-18T00:00:00+00:00
List-Id: <comp.lang.ada>


Hi,

Here's my question:

I would like to write callback routines in Ada83 using DEC Ada 3.0 on VAX/VMS.

I have used e.g. LIB$FILE_SCAN so I know how to use 'ADDRESS to supply callback
subprograms for use by existing routines. What I'd to do is actually call a
callback routine in my program.

I know this is not possible in vanilla Ada83, but ISTR once reading that most
implementations provide a non-portable way of doing this sort of thing.

I guess what I'm hoping for is that somewhere amongst all the DEC provided
routines is something of the form:

   procedure CALL_PROCEDURE ( ADDR : in SYSTEM.ADDRESS ) ;

---

Thanks in advance.

Stephen Davies <sd@eateggs.demon.co.uk>