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From: nr@atomic.Princeton.EDU (Norman Ramsey)
Newsgroups: comp.lang.modula3
Subject: Proposal for change in the RTMisc interface
Message-ID: <1991Apr2.165738.727@newross.Princeton.EDU>
Date: 2 Apr 91 16:57:38 GMT
Sender: news@newross.Princeton.EDU (USENET News System)
Organization: Princeton Computer Science Dept
Lines: 37
Originator: nr@atomic.Princeton.EDU

The current RTMisc interface handles ``cleanup on exit'' as follows:

  TYPE Exitor <: REFANY;
  
  PROCEDURE RegisterExitor (p: PROCEDURE (n: INTEGER)): Exitor;
  (* Registers the procedure p to be executed when Exit is called; it is passed
     the argument of Exit.
     The registered procedures are executed in the reverse order. *)
  
  PROCEDURE UnregisterExitor (e: Exitor);
  (* removes e's procedure from the registered set. *)
  
  PROCEDURE Exit (n: INTEGER);
  (* call the registered exitors and terminate the program with status 'n' *)
  
I propose the following change, to make it possible for exitors to
have more state:

  TYPE Exitor <: REFANY;
  TYPE ExitorClosure = OBJECT METHODS apply(n:INTEGER); END;
  
  PROCEDURE RegisterExitor (p: ExitorClosure): Exitor;
  (* Registers the procedure p to be executed when Exit is called; it is passed
     the argument of Exit.
     The registered procedures are executed in the reverse order. *)
  
  PROCEDURE UnregisterExitor (e: Exitor);
  (* removes e's procedure from the registered set. *)
  
  PROCEDURE Exit (n: INTEGER);
  (* call the registered exitors and terminate the program with status 'n' *)


Comments?
-- 
Norman Ramsey
nr@princeton.edu