From: timr <timrandg@...>
Date: 2011-01-05T06:00:20+09:00
Subject: Re: Is singleton class of an object already created?

Could you simply count singleton_methods? If singleton_methods returns
an empty array, no singleton_class is present. Could easily add that
method to the object class and call it on anything you wanted. But
this strategy equates an empty singlton_method query with not having a
singleton_class. I am not sure that is exactly correct. Though
practically speaking, it seems equivalent to me.
Tim

class Object
  def singleton_class?
    self.singleton_methods.length == 0 ? false : true
  end
end

a = ''
p a.singleton_class?
=> false

def a.singleton_method_for_a
end
p a.singleton_class?
=> true




On Jan 4, 9:28 am, Samnang Chhun <samnang.ch...@gmail.com> wrote:
> Anurag Priyam wrote in post #972264:
> I guess that a singleton class always exists for
>
> > an object, whether a singleton method for that object exists or not.
>
> Sure, singleton class always be there, and it inserted in the
> inheritance chain before the objects "real" class when the first we need
> it. But I would like to generate a diagram of an object's ancestors, if
> the object has used singleton class, then it will show in diagram, but
> it doesn't if object hasn't used singleton class yet.
>
> --
> Posted viahttp://www.ruby-forum.com/.