From: Gary Wright <gwtmp01@...>
Date: 2011-01-07T06:43:31+09:00
Subject: Re: Class Initialization?


On Jan 6, 2011, at 3:06 PM, Kedar Mhaswade wrote:
> 
> And in the process of explaining this, you also indirectly explained one 
> question that was lurking in my mind -- are the 
> attr_readers/writers/accessors available to class variables -- and as I 
> understand it, they are -- by way of your previous class << self 
> construct.

Careful here. The attr* methods are manipulating instance variables and
not class variables.

instance variables:        private to an object
class instance variables:  instance variables for an object that
                           just happens to be a class
class variables:	   nasty, confusing things that have the same name
                           but not at all the same semantics as 'class
                           variables' in other languages
                         

I think it is very unfortunate that a lot of introductory Ruby texts choose
to emphasize class variables (@@foo) over plain old instance variables of
a class (@foo for a class object).

If there were one feature I would remove from Ruby (maybe in Ruby 2.0?) it
would be class variables.


Gary Wright