sample.clj

;基本
(+ 1 1)
(mod 5 4)
(< 1 2 3 4)

;if
(if true (println "True it is."))

;リスト
(list 1 2 3)
(first '(1 2 3))
(rest '(1 2 3))

;セット
(def name #{:jar-jar :chewbacca})
(name :chewbacca)

;マップ
(def mentors {:darth-vader "obi wan", :luke "yoda"})
(mentors :luke)
(:luke mentors)

;関数定義

(defn force-it [] (str "Use the force," "Luke."))
(force-it)

;バインディング
(def line [[0 0] [10 20]])
(defn line-end [ln] (last ln))
(defn line-end [[_ second]] second)

(def board [[:x :o :x] [:o :x :o] [:o :x :o]])
(defn center [[_ [_ c _] _]] c)

(def person {:name "Jabba" :profession "Gangster"})
(let [{name :name} person] (str "The persion's name is " name))

;無名関数
(def people ["Lea", "Han Solo"])
(defn twice-count [w] (* 2 (count w)))
(twice-count "Lando")

(map (fn [w] (* 2 (count w))) people)
(map #(* 2 (count %)) people)

;再帰
;recur1.clj
;recur2.clj

;シーケンス
(every? number? [1 2 3 :four])
(some nil? [1 2 nil])

(reduce + [1 2 3 4])

;遅延評価
(repeat 1)
(take 3 (repeat 1))
(take 5 (cycle [:lather :rinse :repeat]))
(take 5 (iterate inc 0))

(defn fib-pair [[a b]] [b (+ a b)])
(fib-pair [3 5])
(take 5 (iterate fib-pair [1 1]))
(take 5 (map first (iterate fib-pair [1 1])))
(nth (map first (iterate fib-pair [1 1])) 50)

;defrecordとprotocol
;compass.clj

;マクロ
(defmacro unless [test body]
  (list 'if (list 'not test) body))
(macroexpand '(unless condition body))

;参照とSTM
;参照
(def movie (ref "Star Wars"))
@movie
(alter movie str ": The Empire Strikes Back")
(dosync (alter movie str ": The Empire Strikes Back"))

;アトム
(def danger (atom "Split at your own risk."))
@danger
user=> (reset! danger "Split with inpunity")
;atomecache.clj

;エージェント
(defn twice [x] (* 2 x))
(def tribbles (agent 1))
(send tribbles twice)
@tribbles

(defn slow-twice [x]
  (do 
    (Thread/sleep 5000)
    (* 2 x)))
@tribbles
(send tribbles slow-twice)
@tribbles

;フューチャ
(def finer-things (future (Thread/sleep 5000) "take time"))
@finer-things