doc/sod.sty: Hack underscores in the labels generated by `describe'.

[sod] / src / utilities.lisp

diff --git a/src/utilities.lisp b/src/utilities.lisp
index be5ce56c5b1452a18579539f9c53a08b5cba0fc9..98d314aff7ba4a5b4ae9e3edafcb02a3d78e7e09 100644 (file)
--- a/src/utilities.lisp
+++ b/src/utilities.lisp
@@ -693,6 +693,38 @@ (defmacro dosequence ((var seq &key (start 0) (end nil) indexvar)
                      ,(loopguts t t end)
                      ,(loopguts indexvar t nil))))))))))
 
+;;;--------------------------------------------------------------------------
+;;; Structure accessor hacks.
+
+(export 'define-access-wrapper)
+(defmacro define-access-wrapper (from to &key read-only)
+  "Make (FROM THING) work like (TO THING).
+
+   If not READ-ONLY, then also make (setf (FROM THING) VALUE) work like
+   (setf (TO THING) VALUE).
+
+   This is mostly useful for structure slot accessors where the slot has to
+   be given an unpleasant name to avoid it being an external symbol."
+  `(progn
+     (declaim (inline ,from ,@(and (not read-only) `((setf ,from)))))
+     (defun ,from (object)
+       (,to object))
+     ,@(and (not read-only)
+           `((defun (setf ,from) (value object)
+               (setf (,to object) value))))))
+
+(export 'define-on-demand-slot)
+(defmacro define-on-demand-slot (class slot (instance) &body body)
+  "Defines a slot which computes its initial value on demand.
+
+   Sets up the named SLOT of CLASS to establish its value as the implicit
+   progn BODY, by defining an appropriate method on `slot-unbound'."
+  (with-gensyms (classvar slotvar)
+    `(defmethod slot-unbound
+        (,classvar (,instance ,class) (,slotvar (eql ',slot)))
+       (declare (ignore ,classvar))
+       (setf (slot-value ,instance ',slot) (progn ,@body)))))
+
 ;;;--------------------------------------------------------------------------
 ;;; CLOS hacking.