Ruby Hashes emulating Smalltalk Conditionals

HashLikeSmallTalkConditionals.rb

#!/usr/bin/env ruby

module HashLikeSmalltalkConditionals
  class ::Object
    def nil? hash
      hash[:if_false].call
      self
    end
  end

  class ::NilClass
    def nil? hash
      hash[:if_true].call
      self
    end
  end

  def run_example bob
    bob.nil? :if_true => proc { puts 'true' }, :if_false => proc { puts 'false' }
    yield bob if block_given?
  end
end

include HashLikeSmalltalkConditionals
run_example nil
run_example false