CircularEnumerator

circular_enumerator.rb

# Utility converter to make a circular enumerator, wrapping around to the
# beginning of a list after it has exhausted all entries.
#
# Example:
#
# >> e = CircularEnumerator([1,2,3,4,5])
# => #<Enumerator: [1, 2, 3, 4, 5]:each>
#
# >> 10.times.map { e.next }
# => [1, 2, 3, 4, 5, 1, 2, 3, 4, 5]
#
def CircularEnumerator(enumerable)
  e = enumerable.to_enum
  class << e
    def next
      super
    rescue StopIteration
      rewind
      retry
    end
  end
  e
end