gistfile1.rb

class Object
  # Yield ourself to the block given, and let the block determine the value to pass.
  # This is like #tap, but "alter"s the output instead of ignoring it.
  # Useful for conditional scoping, like:
  # # For admins, show all posts. For others, show only public posts.
  # @posts = Post.all.alter{|p| current_user.admin? ? p : p.public}
  #
  # Rather than: note the double assignment :(
  # @posts = Post.all
  # @posts = @posts.public unless current_user.admin?
  def alter
    yield self
  end
end