Index: emacs/lisp/subr.el
diff -c emacs/lisp/subr.el:1.462 emacs/lisp/subr.el:1.463
*** emacs/lisp/subr.el:1.462 Mon Jun 13 20:45:50 2005
--- emacs/lisp/subr.el Mon Jun 13 21:29:52 2005
***************
*** 957,962 ****
--- 957,988 ----
(append (symbol-value list-var) (list element))
(cons element (symbol-value list-var))))))
+
+ (defun add-to-ordered-list (list-var element &optional order)
+ "Add to the value of LIST-VAR the element ELEMENT if it isn't there yet.
+ The test for presence of ELEMENT is done with `equal'.
+
+ The resulting list is reordered so that the elements are in the
+ order given by each element's `list-order' property (a number).
+ Elements which are not symbols, and symbol elements without a
+ numeric `lisp-order' property are placed at the end of the list.
+
+ If the third optional argument ORDER is non-nil and ELEMENT is
+ a symbol, set the symbol's `list-order' property to the given value.
+
+ The return value is the new value of LIST-VAR."
+ (when (and order (symbolp element))
+ (put element 'list-order (and (numberp order) order)))
+ (add-to-list list-var element)
+ (set list-var (sort (symbol-value list-var)
+ (lambda (a b)
+ (let ((oa (and (symbolp a) (get a 'list-order)))
+ (ob (and (symbolp b) (get b 'list-order))))
+ (cond
+ ((not oa) nil)
+ ((not ob) t)
+ (t (< oa ob))))))))
+
;;; Load history
_______________________________________________
Emacs-diffs mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/emacs-diffs
