Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!decwrl!pa.dec.com!src.dec.com!Thomas Roemke <modula-3@uni-paderborn.de>
From: modula-3@uni-paderborn.de (Thomas Roemke)
Newsgroups: comp.lang.modula3
Subject: Local procedure assignment (Bug in M3 1.6 SPARC)?
Message-ID: <9104101603.AA06880@thor.uni-paderborn.de>
Date: 10 Apr 91 16:22:10 GMT
Lines: 43
To: m3
X-Mailer: ELM [version 2.3 PL11]



Assigning a local procedure is illegal. In the case of procedure variables
the compiler has to generate code for verifying this at runtime. The pro-
gram below has to raise an exception (or just terminate execution??), since 
the second assignment to x is illegal (i.e. a local procedure). Am I right ?

	MODULE LProcAssign EXPORTS Main;

	VAR 
	  x: PROCEDURE ();

	PROCEDURE q(p: PROCEDURE (); b: BOOLEAN := TRUE) =
	  PROCEDURE z() = 
	  BEGIN 
	  END z;
	BEGIN
	 x := p;		(* runtime check (b = FALSE => runtime error) *)
	 IF b THEN 
	   q(z,FALSE);		(* correct, local z *)
	 END
	END q;
	  

	PROCEDURE z() = 
	BEGIN 
	END z;

	BEGIN
	 q(z); 			(* correct, global z  *)
	END LProcAssign.



Thomas




-- 
(*	Thomas Roemke, University of Paderborn, Germany 
	modula-3@uni-paderborn.de
	..!uunet!mcsun!unido!pbinfo!modula-3	*)