Not Quite Lisp... or is it ?

Solving the first question of Advent Of Code 2015 \o/

2015/days/01/lisp.lisp

@@ -1,7 +1,19 @@
 ;; Day 1: Not Quite Lisp
 
+(defparameter balance 0)
+
+(defun direction (char) (cond
+                           ((char= char #\()
+                            +1)
+                           ((char= char #\))
+                            -1)
+                        ))
+
 (with-open-file (in "./data/input")
+
   (do ((char (read-char in nil)
              (read-char in nil)))
       ((null char))
-    (print char)))
+    (setf balance (+ balance (direction char)))))
+
+(print balance)