Reverting changes, keeping chouser's work.

Author: Alex Redington

samples/twitterbuzz/src/twitterbuzz/stats.cljs

@@ -1,69 +1,37 @@
-(ns twitterbuzz.stats)
+(ns twitterbuzz.graph)
 
 ;; code review from SDH:
 ;;
-;; 1. I think inc-or-nil could be replaced by fnil - fixed ar
+;; 1. I think inc-or-nil could be replaced by fnil
 ;; 2. update-retweet-count looks broken
-;;    `when` instead of `if` in function to be reduced over - fixed ar
+;;    `when` instead of `if` in function to be reduced over
 ;; 3. conversion from string keys to keywords should be
-;;    done already before we get here - fixed ar 
+;;    done already before we get here
 ;; 4. fns like top-tweets should not take an n arg
-;;    consumers can always take what they want - fixed ar
-;; 5. namespace and file name do not match - fixed ar
+;;    consumers can always take what they want
+;; 5. namespace and file name do not match
+
+(defn inc-or-1
+  "Returns 1 if x is nil, (inc x) otherwise"
+  [x]
+  (if (nil? x) 1 (inc x)))
 
 (defn update-retweet-count
   "Updates the total count of retweets by id in m as indicated by the contents of
   the tweet t"
   [m t]
-  (let [rt-id (get-in t [:retweeted_status :id_str])]
-    (if (nil? rt-id) m (update-in m [rt-id] (fnil inc 0)))))
+  (let [rt-id (get-in t ["retweeted_status" "id_str"])]
+    (when-not (nil? rt-id) (update-in m [rt-id] inc-or-1))))
 
 (defn top-tweets
-  "Returns the ids of the most retweeted tweets out of tweet seq ts in descending
-  order"
-  [ts]
+  "Returns the ids of top n most retweeted tweets out of tweet seq ts"
+  [ts n]
   (let [retweet-counts (reduce update-retweet-count {} ts)
         tweet-ids (keys retweet-counts)]
-    (sort-by #(get retweet-counts %) tweet-ids)))
-
-(defn retweet-of
-  "Returns the username of the user who originally authored the tweet
-  that t is a retweet of, nil otherwise"
-  [t]
-  (get-in t [:retweeted_status :user :name]))
-
-(defn mentioned-users
-  "Returns the usernames of all the users mentioned in tweet t"
-  [t]
-  (map #(get % :screen_name) (get-in t [:entities :user_mentions])))
-
-(defn new-edges
-  "Filter the seq of sets n to find all sets in n that do not already
-  exist in the seq of sets o"
-  [n o]
-  (filter #(not (contains? o %)) n))
-
-(defn edges
-  "Return a lazy seq of pairs of usernames representing the social edges of a tweet
-  stream, where a social edge is defined as one user retweeting or
-  mentioning another user in a given tweet. Edges are not directional; if
-  @alice retweets @bob, and @bob mentions @alice, those two tweets only create
-  one edge."
-  ([ts]
-     (edges ts #{}))
-  ([ts edges]
-     (let [t (first ts)
-           other-users (concat (list (retweet-of t)) (mentioned-users t))
-           author (get-in t [:user :name])
-           tweet-edges (set (map #(set (list author %)) other-users))
-           new-edges (new-edges tweet-edges edges)]
-       (when t
-         (if (empty? new-edges)
-           (recur (rest ts) edges)
-           (lazy-seq (concat new-edges (edges (rest ts) (concat new-edges edges)))))))))
+    (take n (sort-by #(get retweet-counts %) tweet-ids))))
 
 (defn graph
   "Returns a map representing the graph of the tweet seq ts"
   [ts]
-  {:nodes {}
+  {:nodes []
    :edges []})