gistfile1.clj

(extend-type object
  IWithMeta
  (-with-meta [obj meta]
    (set! (.-meta obj) meta) obj)

  IMeta
  (-meta [obj] (.-meta obj))

  IEquiv
  (-equiv [obj other]
    (boolean
     (when (goog/isObject other)
       (when (== (count obj) (count other))
         (every? identity
                 (map (fn [xkv] (= (get other (first xkv) never-equiv)
                                   (second xkv)))
                      obj))))))
  ILookup
  (-lookup [obj k]
    (-lookup obj k nil))
  (-lookup [obj k not-found]
    (let [v (aget obj k)]
      (if (nil? v) not-found v)))

  IAssociative
  (-assoc [obj k v]
    (doto obj
      (goog.object/add k v)))
  (-contains-key? [obj k]
    (goog.object/containsKey obj k))

  ICounted
  (-count [obj] (count (js-keys obj)))

  ISeq
  (-first [obj] (first (seq obj)))
  (-rest [obj] (rest (seq obj)))

  ISeqable
  (-seq [obj]
    (for [k (js-keys obj)]
      [k (aget obj k)])))