take

function

since v0.0-927

clojure.core/take

Edit

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Details:

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See Also:

• drop
• take-while
• take-last
• take-nth

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Source docstring:

Returns a lazy sequence of the first n items in coll, or all items if
there are fewer than n.  Returns a stateful transducer when
no collection is provided.

(defn take
  ([n]
   {:pre [(number? n)]}
     (fn [rf]
       (let [na (volatile! n)]
         (fn
           ([] (rf))
           ([result] (rf result))
           ([result input]
              (let [n @na
                    nn (vswap! na dec)
                    result (if (pos? n)
                             (rf result input)
                             result)]
                (if (not (pos? nn))
                  (ensure-reduced result)
                  result)))))))
  ([n coll]
   {:pre [(number? n)]}
     (lazy-seq
       (when (pos? n)
         (when-let [s (seq coll)]
           (cons (first s) (take (dec n) (rest s))))))))

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