From: Ross Bamford <rossrt@...>
Date: 2006-03-02T00:12:26+09:00
Subject: Re: ruby modules and classes

On Wed, 2006-03-01 at 23:57 +0900, Surendra Singhi wrote:
> Hello,
> 
> When I try the code below I get an error. Why is it so? Am I misunderstanding
> how modules behave? How should the module be written so that `who_am_i' is
> added as a method to the class Phonograph.
> 
> module Debug
>   def self.who_am_i?
>     "#{self.class.name} (\##{self.id}): #{self.to_s}"
>   end
> end
> class Phonograph
>   include Debug
> end
> Phonograph.who_am_i?

Depends what you want, but how about:

	module Debug
	  def who_am_i?
	    "#{self.class.name} (\##{self.object_id}): #{self.to_s}"
	  end
	end

	class Phonograph
	  class << self
	    include Debug
	  end
	end

	p Phonograph.who_am_i?

Or, if you want it as both class and instance methods, I like this
trick:

	module Debug
	  def who_am_i?
	    "#{self.class.name} (\##{self.object_id}): #{self.to_s}"
	  end

	  def self.included(othermod)
	    othermod.extend(self)
	  end
	end

	class Phonograph
	  include Debug
	end

	p Phonograph.who_am_i?
	p Phonograph.new.who_am_i?

(P.s. do you know about Object#inspect?)

-- 
Ross Bamford - rosco@roscopeco.REMOVE.co.uk