main: Ensure WebSocket connection is always closed

Create a new `with-websocket-connection` decorator that starts and
closes a WebSocket connection to the given `client` around the body
forms.

Thanks to Practical Common Lisp's "The Special Operators" chapter
(http://www.gigamonkeys.com/book/the-special-operators.html#unwinding-the-stack)
for introducing me to `unwind-protect`.

Couldn't figure out how to get the new macro to auto-indent properly
with Vlime, so ended up manually indenting it.

1 files changed, 4 insertions, 7 deletions

diff --git a/l/src/main.lisp b/l/src/main.lisp
index d1336d7..969e44f 100644
--- a/l/src/main.lisp
+++ b/l/src/main.lisp
@@ -5,15 +5,12 @@
 (defvar *wg* (wait-group:make-wait-group))
 
 (defun main ()
-  (wsd:start-connection *client*)
+  (with-websocket-connection (*client*)
+    (wsd:on :message *client* #'ws-on-message)
 
-  (wsd:on :message *client* #'ws-on-message)
+    (websocket-send *client* (target-get-targets-msg 1))
 
-  (websocket-send *client* (target-get-targets-msg 1))
-
-  (wait-group:wait *wg*)
-
-  (wsd:close-connection *client*))
+    (wait-group:wait *wg*)))
 
 (defun target-get-targets-msg (call-id)
   (jsown:to-json