From: amit saxena <amit83.saxena@...>
Date: 2008-06-10T17:10:37+09:00
Subject: private class methods- functionality or shortcoming?

"> The Module#private method only works for instance methods,
> not for class 
> method."

My question is, why is it so? What's the advantage in it?

Amit


--- On Mon, 6/9/08, Stefano Crocco <stefano.crocco@alice.it> wrote:

> From: Stefano Crocco <stefano.crocco@alice.it>
> Subject: Re: private class methods- functionality or shortcoming?
> To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
> Date: Monday, June 9, 2008, 7:39 PM
> On Monday 09 June 2008, amit saxena wrote:
> > I just switched to Ruby and came across it.
> > If we have to make a class method private then we
> should write it as:
> >
class Abc
   
    class<<self
        private
        def fun
            p "hello"
        end
    end
   
end

> >But if we write as:

class Abc
   
    private
    def self.fun
        p "hello"
    end

end


> >
> > then the class method is not private but behaves as
> public.
> >
> > So, is it a carefully designed functionality? If so,
> then what is the
> > thinking behind it? OR any other reasons behind it?
> > Somebody told me that ruby encourages to define class
> methods the first
> > way. But I think that if you are giving more than one
> methods to do a
> > thing, then all should function the same way.
> >
> > Thanks and Regards,
> > Amit
> 
> The Module#private method only works for instance methods,
> not for class 
> method. To make a class method private, you should use the 
> Module#private_class_method method. Note that, unlike
> private, 
> private_class_method only accepts one argument, so that you
> want to make more 
> than one method private, you should call it multiple times.
> 
> So, the correct method to make the method private using the
> second form is:
> 
> class Abc
>  
>  def self.fun
>   p "hello"
>  end
>  private_class_method :fun
> 
> end
> 
> I hope this helps
> 
> Stefano