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From: Pat.Terry@p101.f19.n490.z2.fidonet.org (Pat Terry)
Newsgroups: comp.lang.modula2
Subject: Termination code
Message-ID: <846.242C4BE0@dawggon.fidonet.org>
Date: 26 Mar 89 05:13:05 GMT
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Jelske Kloppenberg has asked about module termination.  The forthcoming
draft ISO standard is likely to require a procedure somewhere (in a
required library module) to handle this problem.  The syntax will be
something like

   IMPLEMENTATION MODULE Library;
     FROM Finish IMPORT SetTerminate;

     PROCEDURE TermProc;
       BEGIN
         (* code required for termination when this Library is used *)
       END TermProc;

     BEGIN
       (*Initialisation code*);
       SetTerminate(TermProc)
     END Library.

That is, Finish.SetTerminate(T : PROC) will install T in a stack of
procedures that are called automatically, at least when the program ends
normally or executes HALT.  It is still to be decided what will happen in
other situations (eg when exceptions are raised, coroutines "stop" and so
on).

Incidentally, this feature is already present in many MS-DOS implementations.
JPI, StonyBrook, FST, FTL and Logitech all have it (with slight variations
on how it's actually done).  I suspect it's in many other implementations
too, as it's such an obvious thing to want to do!


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