March 2014 update

Task/Chat-server/Racket/chat-server.rkt

@@ -1,37 +1,21 @@
 #lang racket
 
-(define *client-outputs* (list (current-output-port)))
-
-(define ((tell-all who current-out) line)
-  (for ([out *client-outputs*] #:unless (eq? current-out out))
-    (displayln (~a who ": " line) out)))
-
-(define (serve-client input output)
-  (define nick (begin
-                 (display "Nick: " output)
-                 (read-line input)))
-  (define tell (tell-all nick output))
+(define outs (list (current-output-port)))
+(define ((tell-all who o) line)
+  (for ([c outs] #:unless (eq? o c)) (displayln (~a who ": " line) c)))
 
+(define ((client i o))
+  (define nick (begin (display "Nick: " o) (read-line i)))
+  (define tell (tell-all nick o))
   (let loop ([line "(joined)"])
-    (cond [(eof-object? line)
-           (tell "(left)")
-           (set! *client-outputs* (remq output *client-outputs*))
-           (close-output-port output)]
-          [else
-           (tell line)
-           (loop (read-line input))])))
+    (if (eof-object? line)
+      (begin (tell "(left)") (set! outs (remq o outs)) (close-output-port o))
+      (begin (tell line) (loop (read-line i))))))
 
 (define (chat-server listener)
-  (define-values [client-input client-output] (tcp-accept listener))
-  (file-stream-buffer-mode client-input 'none)
-  (file-stream-buffer-mode client-output 'none)
-  (thread (λ ()
-            (serve-client client-input client-output)))
-  (set! *client-outputs* (cons client-output *client-outputs*))
-  (chat-server listener))
+  (define-values [i o] (tcp-accept listener))
+  (for ([p (list i o)]) (file-stream-buffer-mode p 'none))
+  (thread (client i o)) (set! outs (cons o outs)) (chat-server listener))
 
-(define (start-server)
-  (chat-server (tcp-listen 12321)))
-
-(void (thread start-server))
-(client (current-input-port) (current-output-port))
+(void (thread (λ() (chat-server (tcp-listen 12321)))))
+((client (current-input-port) (current-output-port)))