我已经无耻地举起了我发现的一个示例blogpost中的几乎所有代码(但现在似乎无法检索到),这些代码使用Java的套接字实现来维护简单的IRC连接。在条件范围内使用地图
虽然在这个例子中玩了一下,我遇到了一个问题,我想加入一系列的渠道。我的第一个想法是在服务器var上存储一个通道矢量,然后在模式匹配时对其进行解构。然而,这只是没有奏效。如果我将地图更改为写函数的裸调用,事情就可以正常工作。然而映射写功能似乎不起作用,我对此感到不知所措。有趣的是,如果我将地图调用复制并粘贴到运行活动连接的repl中,它就可以工作......所以这是因为这发生在cond的范围内?裁判有可能被指责吗?我只是闯入Clojure,所以我仍然非常想弄明白。
事不宜迟,下面的代码:
(ns irc
(:import (java.net Socket)
(java.io PrintWriter InputStreamReader BufferedReader)))
(def server {:server "irc.example.net"
:port 6667
:channels ["#a" "#b"]})
(def client {:realname "Lambda Bot" :nick "lambdabot"})
(declare conn-handler)
(defn in [a b]
(re-find (re-pattern a) b))
(defn startswith [a b]
(in (str "^" a) b))
(defn connect [server]
(let [socket (Socket. (:server server) (:port server))
in (BufferedReader. (InputStreamReader. (.getInputStream socket)))
out (PrintWriter. (.getOutputStream socket))
conn (ref {:in in :out out})]
(doto (Thread. #(conn-handler conn server)) (.start))
conn))
(defn write [conn msg]
(println msg)
(doto (:out @conn)
(.println (str msg "\r"))
(.flush)))
(defn conn-handler [conn server]
(while (nil? (:exit @conn))
(let [msg (.readLine (:in @conn))]
(println msg)
(cond
(startswith "ERROR :Closing Link:" msg)
(dosync (alter conn merge {:exit true}))
(in " 001 " msg)
;; this guy below doesn't seem to work at all
(map #(write conn (str "JOIN " %)) (:channels server))
;; this guy on the other hand seems to work fine
;;(write conn (str "JOIN " (first (:channels server))))
(startswith "PING" msg)
(write conn (str "PONG " (re-find #":.*" msg)))))))
(defn login [conn user]
(write conn (str "NICK " (:nick user)))
(write conn (str "USER " (:nick user) " 0 * :" (:realname user))))
要运行这个你可以直接电话咨询:(DEF IRC(连接服务器)),然后(登录IRC客户端)。任何帮助最受赞赏!谢谢。
'(doall(map ...))'偶尔会更容易编写,但我明白了你的观点。 – Cubic
当然啊!由于地图是懒惰的,我应该已经意识到这里发生了什么,但我想我在思想上推迟到REPL的行为,而不考虑它会强制评估。谢谢你放纵我。 – maxcountryman