Discussion on: #GopherDiggingRuby: Intro to blocks in Ruby

[nicholas a. evans]

If you're using this pattern with resources which need to be cleaned up, don't forget to ensure! :)

def get_blender
  blender = take_blender_out_of_cabinet()
  blender.plug_in()

  yield blender
ensure
  if blender
    clean_up blender
    put_away blender
  end
end

Without ensure, your cleanup can be bypassed with

• raise exception anywhere later
• throw tag anywhere down the stack
• break exits the block it's in
• return exits the method it's in

Using ensure get's you back to what you're used to with defer.

[Andy Haskell]

Thanks for sharing that Ruby idiom, I had not heard about that keyword before!