From: Cristian Szegedy <szegedy@...>
Date: 2002-05-11T20:04:33+09:00
Subject: Class variable weirdness

Recently I had some problemin one of my Ruby scripts.
I could reduce it to the following excerpt.
I don't whether it is a bug or a feature, but
I don't really undestand it:

# ---------------------------------

class A
   @@x = 1
   def A.f
     puts @@x
     @@x = 2
     puts @@x
   end
end

class << A
   def g
     puts @@x
     @@x = 3
     puts @@x
   end
end

A.f
A.g

# ---------------------------------

I would have guessed that it outputs

1
2
2
3

In fact the result is :

1
2
2
2

I don't understand the behaviour of A.g:
either it should not be able to read @@x,
or it should be able to write it, or at least it
should issue some warning.

My Ruby is:

ruby 1.6.7 (2002-03-01) [i686-linux]

Thanks in advance,
Christian