owerveight2.clj

(ns overweight.core)

(def animals
  [{:type :cat
    :name "Tom"
    :weight 3}
   {:type :dog
    :breed :boxer
    :weight 12}
   {:type :cat
    :name "Simon"
    :weight 120} ;; Большой  жирный кот
   ])

(defmulti say
  (fn [{:keys [weight type]}]
    (if (> weight 100) :big-animal type)))

(defmethod say :big-animal [animal] "Hru hru")
(defmethod say :dog [_] "Wof wof")
(defmethod say :cat [_] "Miau")

(map say animals) ;; -> ("Miau" "Wof wof" "Hru hru")