# More class variables. Probably shouldn't get into this until you're
# happy with the general idea from classvar.rb. This should demonstrate
# the way that scoping and so on works with classvars.
class A
  @@foo = "class variable foo"
  @foo = "class instance variable foo"

  # Superfluous, but I was learning at this point ;)
  def self.evaluate(txt)
    instance_eval txt
  end
  def self.eval_block(&block)
    instance_eval &block
  end
end
 
begin
  p A.instance_eval { @@foo }
rescue => e
  puts e
end
 
@@foo = "hi"
 
p A.instance_eval { [self, @@foo, @foo] }
p A.evaluate("[self, @@foo, @foo]")
p A.eval_block { [self, @@foo, @foo] }
 
class B
  @@foo = "B's class variable foo"
  @foo = "B instance foo"
  def self.eval_block(&block)
    instance_eval &block
  end
end
 
p B.eval_block { [self, @@foo, @foo] }

class C
  @@foo = "C's class variable foo"
  @foo = "C instance foo"
  def self.eval_block(&block)
    instance_eval &block
  end
end
 
# N.B. Not C, just B again
p B.eval_block { [self, @@foo, @foo] }