Path: utzoo!mnetor!uunet!husc6!uwvax!oddjob!nucsrl!morrison
From: morrison@eecs.nwu.edu (Vance Morrison)
Newsgroups: comp.lang.c++
Subject: Re: Proposal for Exceptions for C++
Message-ID: <8180011@eecs.nwu.edu>
Date: 2 Apr 88 18:11:08 GMT
References: <8180006@eecs.nwu.edu>
Organization: Northwestern U, Evanston IL, USA
Lines: 26

Hello,

	This is in reply to Steve Maurer's suggesting on making 
exceptions look like functions.

There are several problems
	1) It does not allow more than one exceptions handler to be
	   defined for a given exception.  (if a given exception is
	   declaired more than once, which one should it choose?)

	2) MOST times, when an exception is raised, you want to
	   return to the scope of a functions somewhere above you 
	   on the stack, how do you do this?  (longjumps won't work
	   since they do not call destructors properly)

	3) Often you need access to variables that are in the scope
	   of functions above you in the call stack to handle the
	   error properly.  How can you do this?

	In my mind, exceptions are FLOW OF CONTROL constructs.  They
allow you to 'goto' places out of your scope in a controled way.  
exceptions are not functions or data structures, they are more like
fancy 'goto' statements.

					Vance Morrison
					Northwestern Univ.