pipe.clj

(defn pipe
  "Returns a vector containing a sequence that will read from the
   queue, and a function that inserts items into the queue.

   Source: http://clj-me.cgrand.net/2010/04/02/pipe-dreams-are-not-necessarily-made-of-promises/"
  []
  (let [q (LinkedBlockingQueue.)
        EOQ (Object.)
        NIL (Object.)
        s (fn queue-seq []
            (lazy-seq (let [x (.take q)]
                        (when-not (= EOQ x)
                          (cons (when-not (= NIL x) x)
                                (queue-seq))))))]
    [(s) (fn queue-put
           ([] (.put q EOQ))
           ([x] (.put q (or x NIL))))]))