From: David Alan Black <dblack@...>
Date: 2001-10-24T09:26:47+09:00
Subject: [ruby-talk:23126] enough about Python -- here's something fun in Ruby :-)

Hello --

This emerged from some tinkering, and I actually thought it was kind
of cool:

  class Module
    def privately(&block)
      instance_eval "private; block.call; public"
    end
  end

  class Thing
    privately do
      def hidden
	puts "hi"
      end
    end

    def visible
      hidden
    end
  end

  Thing.new.visible  # => hi
  Thing.new.hidden   # => error: hidden method called


I'm not sure why I used instance_eval, rather than some other flavor
of eval.  They all seem to work... though presumably there's something
hidden going on that makes only one (or perhaps none :-) appropriate.


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav