From: Robert Klemme <shortcutter@...>
Date: 2010-03-24T06:57:11+09:00
Subject: Re: Module A extends Moudle B possible?

On 03/23/2010 03:11 AM, Smart RoR wrote:
> Can Modules extends within themselves?
> 
> Like Class A < B is Valid, where B is another class
> Module X < Y is invalid, where Y is another module?

Not directly.  But you can use #included like this:

irb(main):001:0> module A; end
=> nil
irb(main):002:0> module B
irb(main):003:1> def self.included(cl)
irb(main):004:2> cl.class_eval { include A }
irb(main):005:2> end
irb(main):006:1> end
=> nil
irb(main):007:0> class X
irb(main):008:1> include B
irb(main):009:1> end
=> X
irb(main):010:0> X.ancestors
=> [X, A, B, Object, Kernel, BasicObject]
irb(main):011:0>

Note however that the inheritance order is reversed.  There are a number 
of other ways to achieve what you want.  The requirement does not seem 
to come up very frequently though.  So maybe it's not an issue as big as 
you think.

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/