From: Greg McIntyre <greg@...>
Date: 2003-11-30T12:07:08+09:00
Subject: class << x

[ruby-talk:86745] reminded me of something I was going to ask.

I know "class << x" does, but can somebody explain to me the rationale
behind the syntax? How should I "read" it? I currently read it as
"open x's class for modification". Is that right?

I was quite confused about it when I first learned Ruby.

class A
  class << self # what does this mean? (says newbie Greg)
    # ...
  end
end

Even the more "direct" usage is confusing, IMHO:

class B
  # ...
end

b = B.new

class << b # what does this mean? (says newbie Greg)
  def f
    # ...
  end
end

What about this, as an alternative (for Ruby 2?):

class A
  class A # or "class self"
    # ...
  end
end

class b.class
  def f
    # ...
  end
end

-- 
Greg McIntyre ======[ greg@puyo.cjb.net ]===[ http://puyo.cjb.net ]===