ruby_factory_example.rb

class PizzaFactory
  def create_pizza( type )
    case type
    when :ham_mushroom
      HamMushroomPizza.new
    when :deluxe
      DeluxePizza.new
    when :hawaiian
      HawaiianPizza.new
    else 
      raise "The pizza type #{type} is not recognized."
    end
  end
end