Add chat server example.

examples/chatserver.janet

@@ -0,0 +1,35 @@
+(def conmap @{})
+
+(defn broadcast [em msg]
+  (eachk par conmap
+         (if (not= par em)
+           (if-let [tar (get conmap par)]
+             (net/write tar (string/format "[%s]:%s" em msg))))))
+
+(defn handler
+  [connection]
+  (print "created " connection)
+  (net/write connection "Whats your name?\n")
+  (def name (string/trim (string (ev/read connection 100))))
+  (print name " connected")
+  (if (get conmap name)
+    (do
+      (net/write connection "Name already taken!")
+      (:close connection))
+    (do
+      (put conmap name connection)
+      (net/write connection (string/format "Welcome %s\n" name))
+      (defer (do
+               (put conmap name nil)
+               (:close connection))
+        (while (def msg (ev/read connection 100))
+            (broadcast name (string msg)))
+        (print name " disconnected")))))
+
+(defn main [& args]
+  (printf "STARTING SERVER...")
+  (flush)
+  (def my-server (net/listen "127.0.0.1" "8000"))
+  (forever
+   (def connection (net/accept my-server))
+   (ev/call handler connection)))