From: Dossy <dossy@...>
Date: 2002-07-10T01:22:08+09:00
Subject: Re: self_parent

On 2002.07.09, Tom Sawyer <transami@transami.net> wrote:
> 
> essentially what i am trying to create are non-bound, or open, Proc
> objects, in contrast to the type of Proc objects we can create now,
> which are bound to the local variables at the time of creation. I want
> Proc objects that get bound at the time of calling:
> 
> class A
>   def initialize(x)
>     x.call
>   end
>   def display
>     puts 'hello'
>   end
> end
> 
> class B
>   def initialize(x)
>     x.call
>   end
>   def display
>     puts 'goodbye'
>   end
> end
> 
> x = OpenProc { display }
> 
> A.new(x) --> hello
> B.new(x) --> goodbye
> 
> in this way an object can, in effect, ask another object what it should
> do. and that is what i was accomplishing, albiet in a lame way, by
> passing self (and wanting self_parent for).
> 
> so, is there any way to readily accomplish this in ruby?

You said you didn't want to pass self, but given your example
this is what I would do:

class A
  def initialize(k)
    k.call(self)
  end
  def display
    puts 'hello'
  end
end

class B
  def initialize(j)
    j.call(self)
  end
  def display
    puts 'goodbye'
  end
end

y = lambda { |z| z.display }

A.new(y)
B.new(y)


Is there a slightly more detailed example that might better illustrate
what you're trying to do?

-- Dossy

-- 
Dossy Shiobara                       mail: dossy@panoptic.com 
Panoptic Computer Network             web: http://www.panoptic.com/ 
  "He realized the fastest way to change is to laugh at your own
    folly -- then you can let go and quickly move on." (p. 70)