From: "David A. Black" <dblack@...>
Date: 2003-11-30T20:11:02+09:00
Subject: Re: Class-level readers and writers

Hello --

On Sun, 30 Nov 2003, T. Onoma wrote:

> On Saturday 29 November 2003 10:59 pm, Christoph wrote:
> > David A. Black wrote:
> > ...
> >
> > > So that's probably not a great idea in most cases.  Class
> > > variables have their own quirks, though they're scheduled to
> > > be a bit de-quirked in 2.0.
> >
> > My understanding (not that my record in reading Matz 2.0
> > intention is anything I should be bragging about - not that
> > I mind, since I am feeling like a kid in a candy store:-)
> > was that Rite's class variables will behave like today's class
> > instance variables without the need of  ``class attribute
> > accessors''.
> 
> I'm not sure if I'm understanding this correctly. Is the following in any way 
> related:

I don't think so.

[...]

> Or is that class local variable? Cause I'm not understand how @@a "will behave 
> like today's class instance variables without the need of  ``class attribute 
> accessors''."

Matz's description is:

* class variables will be local to the class/module
* if you need to access class variables from outside, 
  define accessors

(See <http://www.rubyist.net/~matz/slides/rc2003/mgp00020.html>.)

So class vars will be able to do what they currently can't do, namely
maintain state on a truly per-class basis (as opposed to
per-hierarchy).  The difference between them and a class's instance
variables, as I understand it, will be that the class variables are
visible from instances of the class.  


David

-- 
David A. Black
dblack@wobblini.net