erubboli

class PizzaFactory
  def create_pizza( type )
    case type
    when :ham_mushroom
      HamMushroomPizza.new
    when :deluxe
      DeluxePizza.new
    when :hawaiian
      HawaiianPizza.new
    else 

erubboli

class Base
  def self.mysql_connector(config)
    #...
  end

  def self.oracle_connector(config)
    #...
  end
end

erubboli

class PizzaFactory {
    public enum PizzaType {
        HamMushroom,
        Deluxe,
        Hawaiian
    }
 
    public static Pizza createPizza(PizzaType pizzaType) {
        switch (pizzaType) {

erubboli

class Currency < ActiveRecord::Base
end

class CurrencyObserver < ActiveRecord::Observer
   observe :currency

   def after_update(currency)
     puts "new rate for #{currency.symbol} : #{currency.rate}"
   end
end

erubboli

require "observer"

class Currency
   include Observable

   def initialize(symbol,rate)
     @rate = rate
     @symbol = symbol
   end

erubboli

#test
class Logger
   def warning( msg )
     #...
   end
end

#production
class SingletonLogger < Logger
   include Singleton

erubboli

class Logger
  include Singleton

  def warning( msg )
    #...
  end

end

a = Logger.instance

erubboli

function ss {
  if [ -e script/rails ]; then
    script/rails server $@
  else
    script/server $@
  fi
}
function sc {
  if [ -e script/rails ]; then
    script/rails console $@

erubboli

class Poker
  def initialize(game)
    @game = game 
  end
 
  def evaluate_cards
      #...
      @game.primitive_operation
      #...
  end

erubboli

class Poker

  def evaluate_cards
     primitive_operation1
     primitive_operation2
  end

  def primitive_operation1
    raise "template method called!"
  end