destructuring-exercises-from-clj-koans.clj

(def test-address
  {:street-address "123 Test Lane"
   :city "Testerville"
   :state "TX"})

;"Destructuring is an arbiter: it breaks up arguments"
(= "__" ((fn [[a b]] (str b a))
       [:foo :bar]))

;"Whether in function definitions"
(= (str "First comes love, "
        "then comes marriage, "
        "then comes Clojure with the baby carriage")
   ((fn [[a b c]] "__")
    ["love" "marriage" "Clojure"]))

;"Or in let expressions"
(= "Rich Hickey aka The Clojurer aka Go Time aka Macro Killah"
   (let [[first-name last-name & aliases]
         (list "Rich" "Hickey" "The Clojurer" "Go Time" "Macro Killah")]
     "__"))

;"You can regain the full argument if you like arguing"
(= {:original-parts ["Stephen" "Hawking"] :named-parts {:first "Stephen" :last "Hawking"}}
   (let [[first-name last-name :as full-name] ["Stephen" "Hawking"]]
     "__"))

;"Break up maps by key"
(= "123 Test Lane, Testerville, TX"
   (let [{street-address :street-address, city :city, state :state} test-address]
     "__"))

;"Or more succinctly"
(= "123 Test Lane, Testerville, TX"
   (let [{:keys [street-address "__" "__"]} test-address]
     "__"))

;"All together now!"
(= "Test Testerson, 123 Test Lane, Testerville, TX"
   ("___" ["Test" "Testerson"] test-address))