def initialize_commands service, stream, mapping
    command_list = [CreateNewFoodCommand, CreateNewRecipeCommand,
      PrintFoodCommand, PrintAllCommand, FindFoodCommand,
      AddItemToLogCommand, ShowLogSummaryCommand,
      ShowLogSummaryTodayCommand, AddItemToLogWithDateCommand,
      ShowLogSummaryWithDateCommand, DeleteItemFromLogCommand,
      DeleteItemFromLogWithDateCommand, SaveCommand
    ]

    command_list.each do |command|
      mapping = command.new(service, stream).populate(mapping)
    end

    return mapping
  end


-----------------------------------------

  def populate mapping
    mapping[@expression] = self
    return mapping
  end