refactoring.clj

;;
;; When refactoring this kind of stuff, I tend to create functions to transform one of the items
;; This way, the threading stuff doesn't get to complicated.
;;

(defn ->sku-name-type [product]
  (let [type (:type product)]
    (->> product
         :variations
          (map val)
          (map (partial merge {:type type})))))

(defn available-stock [availability tuple]
  (->> tuple
       :sku
       str
       keyword
       (get availability)
       (merge tuple)))

(defn low-on-stock [hardwareCatalog availability treshold]
  (->> hardwareCatalog
       (vals)
       (mapcat ->sku-name-type)
       (map (partial available-stock availability))
       (filter #(> treshold (:availableQuantity %)))
       (sort-by :name)))

Thanks a lot, Erik! This is really much nicer. I have modified the blog post to point to your version.