From: Joel VanderWerf <vjoel@...>
Date: 2001-12-15T16:48:56+09:00
Subject: [ruby-talk:28604] assigning to class variable works in string, not in block


In the following code, the first class_eval results in "uninitialized
class variable @@base_class in BaseClass (NameError)". But when I use
"..." instead of {...}, it works as intended. Why this difference? I'm
using Ruby 1.6.5.

module M
  def self.append_features base_class
      base_class.class_eval {@@base_class = self} # fails
#      base_class.class_eval "@@base_class = self" # ok
  end
end

class BaseClass
  include M
end


Note that the following works fine:

class BaseClass
  class_eval {@@base_class = self}
end

--
Joel VanderWerf                          California PATH, UC Berkeley
mailto:vjoel@path.berkeley.edu                     Ph. (510) 231-9446
http://www.path.berkeley.edu                       FAX (510) 231-9512