From: Hidetoshi NAGAI <nagai@...>
Date: 2010-02-15T15:15:12+09:00
Subject: Re: 'def', but with a closure

From: Albert Schlef <albertschlef@gmail.com>
Subject: 'def', but with a closure
Date: Mon, 15 Feb 2010 14:10:36 +0900
Message-ID: <d6e7c0160098036697ba45ba9e00c511@ruby-forum.com>
> It occurred to me several times that I wanted to do:
> 
>   @cars.each do |owner, model|
>     widget = TkLabel.new(:text => model)
>     def widget.get_owner
>       return owner
>     end
>   end
> 
> But, of course, this doesn't work because the code inside 'def' doesn't
> see the enveloping variables, so the 'owner' within the 'def' isn't
> recognized.

e.g.
------------------------------------------------------
labels = @cars.collect{|owner, model|
  TkLabel.new(:text=>model){   # in this block, self is the created widget.
    @owner = owner
    def get_owner
      @owner
    end
  }
}

labels.each{|w| p [w.text, w.get_owner]}
------------------------------------------------------
-- 
Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)