From: Michael Fellinger <m.fellinger@...>
Date: 2008-05-20T09:07:17+09:00
Subject: Re: Using a @@class_variable into a Module

On Mon, May 19, 2008 at 8:02 PM, Iñaki Baz Castillo <ibc@aliax.net> wrote:
> Hi, I want to declare a @@class_variable in class A.
> Class A includes a Module M and I want some methods in M using the
> @@class_variable but I get some problem:
>
> -------------------
> module M
>        def kk
>                #puts (eval %{ #{send('class').class_variables[0]} })
>                puts @@class_var
>        end
> end
>
> class A
>        include M
>        @@class_var = "kaka1"
> end
>
> a = A.new
> a.kk
> NameError: uninitialized class variable @@class_var in M
>        from ./class_attr1.rb:4:in `kk'
> -------------------
>
>
> I understand the problem. Because the nature of class variables when
> the Module M uses @@ it looks into a class variable defined in same
> class/module.
>
> Is there any way I could use a class A @class_var into a included M
> module methods? If not then I'll use a normal attribute but I don't
> like it since it's a constant value that could perfectly be a class
> variable instead of initialiting it in each A instance creation.

So why not making it a constant? Try to stay away from class
variables, they are evil.

> Thanks a  lot.
>
>
> --
> Iñaki Baz Castillo
> <ibc@aliax.net>
>