Building a lazy sequence out of a given subreddit's entries

lazy-reddit.clj

(ns playground.experiments.lazy-reddit
  (:require [net.cgrand.enlive-html :as html]))

(defn subreddit-url [name]
  (str "http://www.reddit.com/r/" name))

(defn fetch-page [url]
  (html/html-resource (java.net.URL. url)))

(defn make-integer [n]
  (try
    (Integer. n)
    (catch Exception e 0)))

(defn page-entries [url]
  (let [page (fetch-page url)
        things (html/select page [:div.thing])]
    (map #(hash-map
           :title (-> % (html/select [:a.title]) first html/text)
           :score (-> % (html/select [:div.score.unvoted]) first html/text make-integer))
         things)))

(defn next-url [url]
  (let [page (fetch-page url)]
    (-> page (html/select [:p.nextprev (html/attr-has :rel "next")]) first :attrs :href)))

(defn entries [url]
  (lazy-cat (page-entries url) (entries (next-url url))))

(defn subreddit [name]
  (-> name subreddit-url entries))

;; (take 30 (subreddit "clojure"))
;; (take-while #(<= (:score %) 6) (subreddit "clojure"))

lazy-reddit.rb

require 'open-uri'
require 'nokogiri'

class Reddit
  def initialize(subbredit)
		@url = "http://www.reddit.com/r/" + subbredit.downcase
		@entries = []
	end

	def entries
		Enumerator::Lazy.new(1..Float::INFINITY) do |yielder|
			if @entries.empty?  
				parse
			else 
				yielder << @entries.shift				
			end
		end
	end

	def reset
		@url.gsub!(/\?.*/, '')
		@entries = []
	end
	
	private

	def parse
		page = Nokogiri::HTML(open(@url))
		@url = page.css('p.nextprev a[rel="nofollow next"]').first['href']
		page.css('div.thing').each do |thing|
			title = thing.css('a.title').text
			points = thing.css('div.score.unvoted').text.to_i
			@entries << { :title => title, :points => points }
		end
	end
end

# r = Reddit.new('ruby')
# r.entries.first(30)
# r.entries.take_while { |e| e[:points] <= 20}.all
# r.reset
# r.entries(1)

project.clj

(defproject playground/experiments "0.1.0"
  :description "Experimenting with Clojure for great fun"
  :dependencies [[org.clojure/clojure "1.5.1"]
                 [com.cemerick/pomegranate "0.2.0"]
                 [enlive "1.1.1"]])