clojure-koans/resources/koans.clj

[["01_equalities" {"__" [true
                      2
                      5
                      true
                      false
                      true
                      true
                      false
                      "hello"
                      "hello"
                      3]}]

 ["02_lists" {"__" [1 2 3 4 5
                 1
                 [2 3 4 5]
                 3
                 0
                 ()
                 [:a :b :c :d :e]
                 [:e :a :b :c :d]
                 :a
                 [:b :c :d :e]
                 "No dice!"
                 ()]}]

 ["03_vectors" {"__" [1
                   [1]
                   [nil nil]
                   2
                   [111 222 333]
                   :peanut
                   :jelly
                   :jelly
                   [:butter :and]
                   3]}]

 ["04_sets" {"__" [[3]
                3
                #{1 2 3 4 5}
                #{1 2 3 4 5}
                #{2 3}
                #{1 4}]}]

 ["05_maps" {"__" [:b 2
                1
                2
                2
                1
                1
                "Sochi"
                nil
                :key-not-found
                true
                false
                "February"
                1 "January"
                2010 2014 2018
                "PyeongChang" "Sochi" "Vancouver"]}]

 ["06_functions" {"__" [81
                     20
                     10
                     60
                     15
                     30]
               "___" [+
                      *
                      (fn [f] (f 5))
                      (fn [f] (f 5))]}]

 ["07_conditionals" {"__" [:a
                        []
                        nil
                        :glory
                        4 6 :your-road
                        1
                        :bicycling
                        "is that even exercise?"]}]

 ["08_higher_order_functions" {"__" [4 8 12
                                  (* x x)
                                  [false false true false false]
                                  ()
                                  [:anything :goes :here]
                                  (< x 31)
                                  (* 10 x) (< x 4)
                                  24
                                  100
                                  (count a) (count b)]}]

 ["09_runtime_polymorphism" {"__" [(str (:name a) " eats veggies.")
                                (str (:name a) " eats animals.")
                                (str "I don't know what " (:name a) " eats.")
                                "Hello World!"
                                "Hello, you silly world."
                                "Hello to this group: Peter, Paul, Mary!" ]}]

 ["10_lazy_sequences" {"__" [[1 2 3 4]
                          [0 1 2 3 4]
                          10
                          95
                          (range 20)
                          :a]
                    "___" [(fn [x] x)]}]

 ["11_sequence_comprehensions" {"__" [[0 1 2 3 4 5]
                                   (* x x)
                                   (range 10)
                                   (odd? x) (* x x)
                                   [row column]
                                   ]}]

 ["12_creating_functions" {"__" [true false true
                              4
                              :a :b :c :d
                              :c :d
                              4
                              8]
                        "___" [(complement nil?)
                               multiply-by-5
                               (comp dec square)]}]

 ["13_recursion" {"__" [true
                     acc
                     (loop [coll coll
                            acc ()]
                       (if (seq coll)
                         (recur (rest coll) (conj acc (first coll)))
                         acc))
                     (loop [n n
                            acc 1]
                       (if (zero? n)
                         acc
                         (recur (dec n) (* acc n))))]
               "___" [not]}]

 ["14_destructuring" {"__" [":bar:foo"
                         (format (str "An Oxford comma list of %s, "
                                      "%s, "
                                      "and %s.")
                                 a b c)
                         (apply str
                                (interpose " "
                                           (apply list
                                                  first-name
                                                  last-name
                                                  (interleave (repeat "aka") aliases))))
                         {:original-parts full-name
                          :named-parts {:first first-name :last last-name}}
                         (str street-address ", " city ", " state)
                         city state
                         (str street-address ", " city ", " state)]
                   "___" [(fn [[fname lname]
                              {:keys [street-address city state]}]
                            (str fname " " lname ", "
                                 street-address ", " city ", " state))
                          ]}]

 ["15_refs" {"__" ["hello"
                "hello"
                "better"
                "better!!!"
                (dosync (ref-set the-world 0))
                (map :jerry [@the-world @bizarro-world])
                ]
          "___" [(fn [x] (+ 20 x))]}]

 ["16_atoms" {"__" [0
                 1
                 (swap! atomic-clock (partial + 4))
                 20
                 20
                 atomic-clock 20 :fin
                 ]}]

 ["17_macros" {"__" [~(first form)
                  ~(nth form 2)
                  form
                  (drop 2 form)
                  "Hello, Macros!"
                  10
                  '(+ 9 1)
                  '(* 10 2)
                  '(+ 10 (2 * 3))]}]

 ["18_datatypes" {"__" [(print
                      (str "You're really the "
                           (.category this)
                           ", " recipient "... sorry."))
                     "peace"
                     "literature"
                     "physics"
                     nil
                     [true false]
                     (str "Congratulations on your Best Picture Oscar, "
                          "Evil Alien Conquerors!")]}]

 ["19_java_interop" {"__" [java.lang.String
                        "SELECT * FROM"
                        10
                        1024
                        ]
                  "___" [#(.toUpperCase %)
                         ]
                  }]
 ["20_partition" {"__" [partition
                        [:a :b :c]
                        '((0 1 2) (3 4))
                        5
                        :hello
                        (6 :these :are)
                        ]}]
 ["21_group_by" {"__" [odd?
                       {5 ["hello" "world"] 3 ["foo" "bar"]}
                       {1 [{:name "Bob" :id 1}
                           {:last-name "Smith" :id 1}]
                        2 [{:name "Jennifer" :id 2}]}
                       nil
                       {:naughty-list [{:name "Jimmy" :bad true}
                                       {:name "Joe" :bad true}]
                        :nice-list [{:name "Jane" :bad false}]}]}]
 ["22_meta" {"__" [{:league "National League"}
                   {:division "West"}
                   "This doesn't implement the IObj interface"
                   {:foo :bar}
                   nil
                   \C
                   inc
                   :park "AT&T Park"
                   'Giants
                   "Giants"]}]
]