chat.clj

(import [java.io PrintStream]
         [java.util Scanner]
         [java.net ServerSocket])
(use '[clojure set])

(defn serve
  [service port]
  (let [server (ServerSocket. port)]
    (while (not (.isClosed server))
      (let [sock (.accept server)]
        (future (service sock))))))

(comment
(defn echo [sock]
  (let [in (Scanner. (.getInputStream sock)) 
        out (PrintStream. (.getOutputStream sock))]
    (while (.hasNextLine in)
      (.println out (.nextLine in)))))
)
      
(defn chat-serve [port]
  (let [clients (atom #{})]
    (serve
     (fn [sock]
	 (swap! clients conj sock)
	 (let [in (Scanner. (.getInputStream sock))]
	   (while (.hasNextLine in)
		  (doseq [line [(.nextLine in)]
			       out (map #(PrintStream. (.getOutputStream %))
					(difference @clients [sock]))]
			 (.println out line))))
	 (swap! clients difference [sock]))
     port)))