+(defun outline-invent-heading (head up)
+ (save-match-data
+ ;; Let's try to invent one by repeating or deleting the last char.
+ (let ((new-head (if up (substring head 0 -1)
+ (concat head (substring head -1)))))
+ (if (string-match (concat "\\`\\(?:" outline-regexp "\\)")
+ new-head)
+ ;; Why bother checking that it is indeed higher/lower level ?
+ new-head
+ ;; Didn't work, so ask what to do.
+ (read-string (format "%s heading for `%s': "
+ (if up "Parent" "Demoted") head)
+ head nil nil t)))))
+