X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/sod/blobdiff_plain/dc162ca6f0f2bbcb045a03df61c76e37c48d85a7..c34b237da0bb4bf08a3531a2e11442623df7e9d4:/src/utilities.lisp?ds=inline

diff --git a/src/utilities.lisp b/src/utilities.lisp
index 72423fd..72af8b3 100644
--- a/src/utilities.lisp
+++ b/src/utilities.lisp
@@ -708,6 +708,17 @@ (defun compose (function &rest more-functions)
 	       (multiple-value-call func-b (apply func-a args)))))
     (reduce #'compose1 more-functions :initial-value function)))
 
+;;;--------------------------------------------------------------------------
+;;; Variables.
+
+(export 'defvar-unbound)
+(defmacro defvar-unbound (var doc)
+  "Make VAR a special variable with documentation DOC, but leave it unbound."
+  `(eval-when (:compile-toplevel :load-toplevel :execute)
+     (defvar ,var)
+     (setf (documentation ',var 'variable) ',doc)
+     ',var))
+
 ;;;--------------------------------------------------------------------------
 ;;; Symbols.