#jsとclj->jsの違いについて ref: http://qiita.com/kurogelee/items/b98d9d924000664a3a48

core.cljs抜粋

(defn clj->js
   "Recursively transforms ClojureScript values to JavaScript.
sets/vectors/lists become Arrays, Keywords and Symbol become Strings,
Maps become Objects. Arbitrary keys are encoded to by key->js."
   [x]
   (when-not (nil? x)
     (if (satisfies? IEncodeJS x)
       (-clj->js x)
       (cond
         (keyword? x) (name x)
         (symbol? x) (str x)
         (map? x) (let [m (js-obj)]
                    (doseq [[k v] x]
                      (aset m (key->js k) (clj->js v)))
                    m)
         (coll? x) (let [arr (array)]
                     (doseq [x (map clj->js x)]
                       (.push arr x))
                     arr)
         :else x))))

file0.cljs

(identity #js [[[1 2]]])
(clj->js [[[1 2]]])

reader.cljs抜粋

(defn ^:private read-js
  [form]
  (cond
    (vector? form)
    (let [arr (array)]
      (doseq [x form]
        (.push arr x))
      arr)

    (map? form)
    (let [obj (js-obj)]
      (doseq [[k v] form]
        (aset obj (name k) v))
      obj)

    :else
    (reader-error nil
      (str "JS literal expects a vector or map containing "
           "only string or unqualified keyword keys"))))