ClojureでL-99 (P14 要素を2回繰り返す)

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2008-10-01

Clojure, L-99 | 13:09 |

Clojureにも畳み込み用のreduceがあります。

(defn
  #^{:doc "P14 (*) Duplicate the elements of a list."
     :test (do (test= (dupli []) [])
               (test= (dupli '(a b c c d))
                      '(a a b b c c c c d d))) }
; -----
  dupli
; -----
  ([coll]
     (reduce #(concat % (list %2 %2))
             []
             coll)))

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