gistfile1.rb

class Card
  include Comparable
  attr_reader :rank
  
  FACE_CARDS = {
    'ace'   => 1,
    'jack'  => 11,
    'queen' => 12,
    'king'  => 13
  }
  
  def initialize(rank)
    @rank = cast_rank(rank)
  end
  
  def <=>(other_card)
    self.rank <=> other_card.rank
  end
  
  private
  
    def cast_rank(rank)
      rank = FACE_CARDS[rank] || rank.to_i
      if rank.nil? || !(1..13).include?(rank)
        raise ArgumentError, "rank must be: 1-13, 'jack', 'queen', 'king', or 'ace'"
      end
      rank
    end
end

class Deck
  include Enumerable
  attr_reader :cards
  
  def initialize
    @cards = []
    52.times { @cards << Card.new(rand(13) + 1) }
  end
  
  def each
    @cards.each { |c| yield c }
  end
  
  def deal(num)
    dealt_cards = []
    num.times { dealt_cards << @cards.pop }
    dealt_cards
  end
  
  def peek
    @cards.last
  end
  
  def shuffle!
    100.times do
      @cards << @cards.delete_at(rand(count))
    end
  end
end