From: Yukihiro Matsumoto <matz@...>
Date: 2009-09-29T13:32:06+09:00
Subject: Re: Inconsistent behavior of singleton methods that access class 	variables: 1.8.7 vs 1.9.2

Hi,

In message "Re: Inconsistent behavior of singleton methods that access class 	variables: 1.8.7 vs 1.9.2"
    on Mon, 28 Sep 2009 04:06:42 +0900, Nikolai Lugovoi <nlugovoi@gmail.com> writes:

|So, the question is, what is the correct way to declare and use such
|constructs, and what caused the problem -- bug in ruby or incorrect
|use of class variables?

The basic rules for class variables are:

 (1) initialize at class variables at the top of the scope (in this
     case, A).

 (2) avoid name conflict of class variables in the same top-level
     scope; in the case of the example, you used @@list several times
     in the scope of A.

 (3) and lastly, and most importantly, do not use class variables,
     unless you really really need them; they are fundamentally global
     variables.

You've violated all of above rules.

							matz.