Adding callbacks in Ruby

key-callbacks.rb

class Client
  def initialize
    @callbacks = {}

    set_key 'q', method(:quit)
  end 

  def set_key(key, callback)
    @callbacks[key] = callback
  end 

  def quit
    throw :quit_loopy
  end 

  def loopy
    catch :quit_loopy do
      loop do
        c        = getc
        callback = @callbacks[c]

        next if callback.nil?

        callback.call
      end 
    end 
  end 
end