gistfile1.rb

class Die
  def initialize(labels)
    @labels = labels
  end
  def sides
    @labels.length
  end
  def roll
    if @labels == []
      raise ArgumentError.new("Labels list is empty")
    end
    count = (0..@labels.length).to_a
    hash = Hash[count.zip @labels]
    hash[rand(@labels.length)]
  end
end