a-deeper-look-at-rubys-enumerable-example-2

example-3.rb

class Roll < Array

  def small_straight?
    sort.each_cons(4).any? {|vals| in_series?(vals)  }
  end

  def large_straight?
    sort.each_cons(5).all? {|vals| in_series?(vals)  }
  end

private

  def in_series?(vals)
    vals == (vals.first..vals.last).to_a
  end

end

Roll.new([1,3,4,5,6]).small_straight? #=> true
Roll.new([1,3,4,5,6]).large_straight? #=> false
Roll.new([2,3,4,5,6]).large_straight? #=> true