From: Daniel Nugent <nugend@...>
Date: 2005-09-09T02:20:18+09:00
Subject: Re: The Laziest Variable in the Whooole World

How about using Thread.pass to avoid sitting in the loop while your
resources could be better spent elsewhere?

UPDATED SAMPLE:

class Lazy

 #DESTROY ALL METHODS!  DESTROY ALL INSTANCE METHODS!
 instance_methods.each { |m| undef_method m unless m =~ /^__/ }

 def initialize(switch = :one_eval, &block)
   @code_block = block
   @mode = switch
 end

 def method_missing(symbol, *args)
   if @mode == :one_eval
     @real_obj ||= @code_block.call
     @real_obj.__send__(symbol, *args)
   else
     @code_block.call().__send__(symbol, *args)
   end
 end
end


#Dataflow example
foo = Lazy.new do
 while ! defined? $dfv
 	Thread.pass
 end
 $dfv
end

bar = Thread.new {print foo}
baz = Thread.new {sleep(3);$dfv = "Hello World, sorry I'm late"}

bar.join
baz.join

-- 
-Dan Nugent