From: Sean O'Dell <sean@...>
Date: 2004-06-16T05:38:45+09:00
Subject: Re: undefine

On Tuesday 15 June 2004 11:45, Mark Hubbart wrote:
> On Jun 15, 2004, at 10:19 AM, tony summerfelt wrote:
> > On Tue, 15 Jun 2004 14:55:05 +0900, you wrote:
> >>> I did not advocate removing, a.k.a. undefining,
> >>> instance variable,
> >
> > it would be a local variable i'd be undefining, probably not an
> > instance variable (although i'd like that option also)
>
> I think the whole point here is that it isn't Ruby-ish to rely on a
> variable being defined or not. Ruby wassn't built to do things in that
> way; a couple examples in this thread show how variables are
> automagically defined when code is parsed. They aren't defined at
> runtime, they are defined at eval time. So basically, If you are
> translating code from Perl that undefines local variables, you will
> have to find a different way of doing it, due to the way Ruby was
> designed. I doubt that this is likely to change, because it's part of
> how Ruby was designed.

Actually, Matz could probably very easily expose variables as objects 
themselves to be manipulated like anything else in Ruby.  I don't think 
because he hasn't done it yet constitutes a "design decision" as much as 
"something he didn't do."  It's not impossible, in other words, it's just a 
feature that doesn't exist yet.

	Sean O'Dell