如何按类型合并clojure列表中的项？

(def list1 '(1 2 3))
(def list2 '(4 5 6))
(def merged-list (concat list1 list2))
;; => (1 2 3 4 5 6)

(def mixed-list '(1 "two" 3 "four" 5))
(def grouped-by-type (partition-by type mixed-list))
;; => ((1 3 5) ("two" "four"))

(def merged-by-type (map #(apply str %) grouped-by-type))
;; => ("135" "twofour")

(def items [{:type :a :value 1} {:type :b :value 2} {:type :a :value 3}])
(def merged-items (reduce (fn [acc item]
                           (update acc item :value + (get item :value 0)))
                         {}
                         items))
;; => {:a 4 :b 2}

(defmacro merge-items [items]
  `(reduce (fn [acc item#]
             (update acc (:type item#) + (:value item#)))
           {}
           ~items))

(def items [{:type :a :value 1} {:type :b :value 2} {:type :a :value 3}])
(def merged-items (merge-items items))
;; => {:a 4 :b 2}