From: Lyle Johnson <lyle@...>
Date: 2003-12-03T02:57:08+09:00
Subject: Re: Attempted roadmap of future instance variables....

Steve Tuckner wrote:

> So @_var does not refer to the class instance variable @var?

Correct. @_var and @var refer to two *different* instance variables.

> If @_var defined in a class context is different from @_var in an instance then how
> does one refer to the @_var created in the instance context in the class
> context?

If I parsed that question correctly, the answer is "you don't" ;)

Generally speaking, there isn't any way for the *class* of an instance 
to refer to its instance's instance variables.

> I would think that @_var in the instance context should be the same as
> refering to the @var in the class context. It would be like having
> attr_accessor for @var with a little sugar for the instance context.

I'm not sure, but I think you may be under the impression that @_var and 
@var are somehow linked to each other, and they aren't. (Perhaps David 
should have used completely different names in the original example).

For C++ programmers, the easiest way to think of this is that a Ruby 
instance variable whose name starts with an underscore (such as @_foo) 
is private, in the C++ sense. An instance variable whose name doesn't 
start with an underscore (such as @bar) is protected, again in the C++ 
sense.

Unless, of course, I am completely confused ;)