gistfile1.txt

(->  (:user_id (get-cur-user request))
     db/get-cart-items
     (partial map
              #(assoc %1
                 :cart_item
                 (db/get-dress (:cart_item_id %1)))) ;; breaks here, I want to take the maps from get-cart-items and returns
                                                        maps where cart-item is a key in map, and a dress from db is the value. 
                                                        (fetched using the cart-item-id from the map)
     json/write-str)

;; java.lang.Exception: Don't know how to write JSON of class clojure.core$partial$fn__4072

;; ========= how come the above throws an error, but the followin works?

(def pull-dress
  (partial map
              #(assoc %1
                 :cart_item
                 (db/get-dress (:cart_item_id %1)))))

(-> (:user_id (get-cur-user request))
     db/get-cart-items
     pull-dress
     json/write-str)