Clojure需要花费更多时间

Question

Clojure在take-while-and-n-more下面实现的惯用方法是什么:

=> (take-while-and-n-more #(<= % 3)  1 (range 10))
(0 1 2 3 4)

我的尝试是:

(defn take-while-and-n-more [pred n coll]
  (let
      [take-while-result (take-while pred coll)
       n0 (count take-while-result)] 
    (concat
     take-while-result
     (into [] (take n (drop n0 coll))))))

Answer 1

我会使用split-with,这相当于获取相同参数的take-while和drop-while的结果:

(defn take-while-and-n-more [pred n coll]
    (let [[head tail] (split-with pred coll)]
         (concat head (take n tail))))