Allow CLark to be used from the lisp REPL

lisp/clark.lisp

@@ -35,8 +35,8 @@
 (defvar *script* nil
   "Whether or not to output in a machine-readable format.")
 
-(defvar *exit-status* 0
-  "The exit status to use on quit.")
+(define-condition exiting ()
+  ((exit-code :initform 0 :initarg :code :reader exit-code)))
 
 (defmacro call-command (name &rest args)
   (let ((command-name (make-command-name (symbol-name name))))
@@ -49,8 +49,7 @@
     `(progn
        (defun ,command-name (,@args)
          ,sdoc
-         ,@body
-         (sb-ext:exit :code *exit-status*))
+         ,@body)
        (setf *help-messages*
              (nconc *help-messages* '((,sname ,sdoc ,ldoc)))
              *max-command-name-length*
@@ -67,8 +66,10 @@ the help command."
   "Bind `*exit-status*' to CODE, `*standard-output*' to
 `*error-output*' and execute BODY."
   `(let ((*standard-output* *error-output*)
-         (*exit-status* ,code))
-     ,@body))
+         (exit-status ,code))
+     ,@body
+     (when (> exit-status 0)
+       (signal 'exiting :code exit-status))))
 
 (defparameter version "0.1.1"
   "Clark's version.")
@@ -197,5 +198,7 @@ Connect to the database, parse command-line arguments, execute and
 then disconnect."
   (load-rc)
   (load-db)
-  (parse-args (cdr args))
-  (disconnect *db*))
+  (handler-case
+      (unwind-protect (parse-args (cdr args))
+        (disconnect *db*))
+    (exiting (c) (sb-ext:exit :code (exit-code c)))))