X-Git-Url: http://git.kpe.io/?p=kmrcl.git;a=blobdiff_plain;f=macros.lisp;h=d0ba63c629d8e698cc011c6072ce82c20e7d604d;hp=c83b3b64a19f9f9be26f9dd96daa9ed9213f6f6d;hb=9e36114ec80a5a8b58a650a5f80b4d51b43d0ce0;hpb=36e2522dde1173c28300156cb718779d5858c36d

diff --git a/macros.lisp b/macros.lisp
index c83b3b6..d0ba63c 100644
--- a/macros.lisp
+++ b/macros.lisp
@@ -264,8 +264,16 @@
      (format t "~%~%")
      (values)))
 
-(defmacro defconst (symbol value &optional doc)
-   `(defconstant ,symbol (if (boundp ',symbol)
-                             (symbol-value ',symbol)
-                             ,value)
+(defmacro defconstant* (sym value &optional doc)
+  "Ensure VALUE is evaluated only once."
+   `(defconstant ,sym (if (boundp ',sym)
+			  (symbol-value ',sym)
+			  ,value)
      ,@(when doc (list doc))))
+
+(defmacro defvar-unbound (sym &optional (doc ""))
+    "defvar with a documentation string."
+    `(progn
+      (defvar ,sym)
+      (setf (documentation ',sym 'variable) ,doc)))
+