1 files changed, 16 insertions, 0 deletions
diff --git a/Lisp/internal-utilities.lisp b/Lisp/internal-utilities.lisp
index 1c54068..9be74a9 100644
--- a/Lisp/internal-utilities.lisp
+++ b/Lisp/internal-utilities.lisp
@@ -27,6 +27,22 @@
   (member symbol *features*))
 
 
+(defun objc-null (value)
+  (or (null value)
+      (and (typep value 'c-pointer-wrapper)
+           (objc-pointer-null (pointer-to value)))))
+
+
+(defmacro objc-or (&rest forms)
+  (let ((sym (gensym)))
+    `(let ((,sym ,(first forms)))
+       (if (objc-null ,sym)
+           ,(if (rest forms)
+                `(objc-or ,@(rest forms))
+                'nil)
+           ,sym))))
+
+
 (defmacro with-foreign-string-pool ((register-fn-name) &body body)
   (let ((pool-var (gensym)))
     `(let ((,pool-var (list)))