gistfile1.rb

# From top comment on http://www.reddit.com/r/ruby/comments/29hr4x/whats_youre_favorite_ruby_trick_or_quirk_that/?utm_source=rubyweekly&utm_medium=email


class FakeRedditApi

  def initialize
    @count = 0
  end

  def has_next_post?
    @count < 20
  end

  def next_post
    @count+=1
    puts "Fetching Post #{@count}"
    ["kitty picture", "karma-whoring repost", "bitcoin circlejerk"].sample
  end

end

class RedditApiService
  def initialize
    @api = FakeRedditApi.new
  end

  #coroutine demo
  def fetch_posts
    return to_enum(__callee__) unless block_given?

    while @api.has_next_post?
      yield @api.next_post
    end
  end

end


reddit = RedditApiService.new

#Will fetch no posts, just return enumerator
reddit.fetch_posts


#Will fetch 5 posts
reddit.fetch_posts.take(5)