Add `with_position_and_size` method to Enumerator. Those are quite handy inside a loop.

enumerator_with_position_and_size.rb

module EnumeratorWithPositionAndSize

  # @yields [original_params, position_and_size]
  # @yieldparam position_and_size [(Integer, Integer)] 2-element array of position (first being 1) and size; size may be nil (see Enumerator#size)
  # @example
  #  %w[a b c d e].each.with_position_and_size { |char, (position, size)| puts "#{char} (#{position}/#{size})" }
  def with_position_and_size
    return to_enum(__method__) unless block_given?
    my_size = self.size
    self.with_index(1) do |original_params, position|
      yield original_params, [position, my_size]
    end
  end

end

Enumerator.send(:include, EnumeratorWithPositionAndSize)