class DictionaryPresenter
  include Enumerable
  def initialize(collection)
    @dictionary = ('A'..'Z').each_with_object({}){|l,h| h[l] = []}
    collection.each{|p| @dictionary[p.title[0]] << p}
  end
  def each &block
    @dictionary.each(&block)
  end
end
@posts = DictionaryPresenter.new(Post.all).as_dictionary
# changed to this
@posts = DictionaryPresenter.new(Post.all)