Javaのラムダ使うAPIとClojureをちょこっと比較してみる ref: http://qiita.com/kurogelee/items/c032ae51c82a80cd7a97

Cycle.java

static <T> Stream<T> cycle(T t0, T... ts){
    return Stream.generate(new Supplier<T>() {
        int index = -1;
        @Override
        public T get() {
            index = (index + 1) % (ts.length + 1);
            if(index == 0){
                return t0;
            }
            return ts[index - 1];
        }
    });
}

drop_take_reduce.clj

(->> (range 1 10)
     (drop 3)
     (take 5)
     (reduce *)
     println)

map-vals-with-key.clj

(defn map-vals-with-key [f hmap]
  (reduce (fn [hmap [k v]] (assoc hmap k (f k v))) hmap hmap))

MergeWith.java

public static <K, V> Map<K, V> mergeWith(Map<K, V> m1, Map<K, V> m2, BinaryOperator<V> f){
    m2.forEach((k2, v2) -> {
        m1.computeIfPresent(k2, (k1, v1) -> f.apply(v1, v2));
        m1.putIfAbsent(k2, v2);
    });
    return m1;
}

range_filter_map_doseq.clj

(->> (range 1 10)
     (filter #(zero? (rem % 2)))
     (map #(* % 3))
     (#(doseq [i %] (println i))))

range_filter_map_forEach.java

IntStream.range(1, 10)
        .filter(i -> i % 2 == 0)
        .map(i -> i * 3)
        .forEach(System.out::println);

skip_limit_reduce.java

IntStream.range(1, 10)
        .skip(3)
        .limit(5)
        .reduce((i, j) -> i * j)
        .ifPresent(System.out::println);