move update-on-change! before first use.

clojurescript being compiled to javascript allows this (hoisted
variables), but it emits a warning and might be confusing/non-idiomatic.

clj/clarity/cljs/clarity.cljs

                 [k (empty-value v)])
               entries))))
(defn update-on-change!
  ([m k] (update-on-change! m k identity))
  ([m k transform-fn] (update-on-change! m k transform-fn false))
  ([m k transform-fn optional?]
   (fn [ev]
     (let [new-val (transform-fn (.. ev -target -value))]
       (if (and optional? (empty? new-val))
         (om/update! m dissoc k)
         (om/transact! m k (fn [_ n] n) new-val))))))
(defmulti make-typed-input
  (fn [_ _ {type :type} & _]
    (cond
                    :pattern keyword-pattern
                    :onChange (update-on-change! m key #(or (read-keyword %) (empty-value type)))})))
(defn update-on-change!
  ([m k] (update-on-change! m k identity))
  ([m k transform-fn] (update-on-change! m k transform-fn false))
  ([m k transform-fn optional?]
   (fn [ev]
     (let [new-val (transform-fn (.. ev -target -value))]
       (if (and optional? (empty? new-val))
         (om/update! m dissoc k)
         (om/transact! m k (fn [_ n] n) new-val))))))
(defmethod make-typed-input 'String [m owner {:keys [type key val optional?]}]
  (om/component
    (dom/input #js {:type "text"