## Documents pattern helps to save memory & cpu time providing cheap OO interface for the arrays of raw data without need to instantiate a lot of objects.

class Documents
  include Enumerable
  def initialize(collection)
    @collection = collection
    @element = collection.first
  end
  def each
    @collection.each do |raw_element|
      @element = raw_element
      yield self
    end
  end
end

# Regular class (object per element)
class Video
  def actor
    @actor  # instance data
  end
end

# Wrapper for an array (one object for many elements)
class Videos < Documents
  def actor
    @element["actor"] # raw data of the current element
  end
end


## USAGE

# non-optimized:

raw_data = [{"actor" => "Arnold"}, {"actor" => "Charles"}, ...]

videos = raw_data.map{|r| Video.new(r) }
videos.each do |video|
  # do something with video
end

# optimized:

videos = Videos.new(raw_data)
videos.each do |video|
  # do something with video (fake enumerator with the same interface as Video)
end