Apparently gnu emacs has this, and it's a comparatively easy thing to add, so I thought it'd be worth trying to add. These are the diff lines from comparing with http://hg.debian.org/hg/xemacs/xemacs-beta searching for changes changeset: 4425:fa7844674ed2 user: bpalmer(a)bpalmer-mac.local date: Mon Feb 25 04:45:41 2008 -0800 summary: * subr.el(add-to-list): add support for `compare-fn' to sync with diff -r 42711a251efd -r fa7844674ed2 lisp/subr.el --- a/lisp/subr.el Fri Feb 15 13:11:56 2008 +0100 +++ b/lisp/subr.el Mon Feb 25 04:45:41 2008 -0800 ＠＠ -390,19 +390,21 ＠＠ argument to `add-one-shot-hook'." argument to `add-one-shot-hook'." (add-one-shot-hook hook function append t)) -(defun add-to-list (list-var element &optional append) +(defun add-to-list (list-var element &optional append compare-fn) "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'. -If ELEMENT is added, it is added at the beginning of the list, -unless the optional argument APPEND is non-nil, in which case -ELEMENT is added at the end. +The test for presence of ELEMENT is done with COMPARE-FN; if +COMPARE-FN is nil, then it defaults to `equal'. If ELEMENT is added, +it is added at the beginning of the list, unless the optional argument +APPEND is non-nil, in which case ELEMENT is added at the end. If you want to use `add-to-list' on a variable that is not defined until a certain package is loaded, you should put the call to `add-to-list' into a hook function that will be run only after loading the package. `eval-after-load' provides one way to do this. In some cases other hooks, such as major mode hooks, can do the job." - (if (member element (symbol-value list-var)) + (if (if (not compare-fn) + (member element (symbol-value list-var)) + (member* element (symbol-value list-var) :test compare-fn)) (symbol-value list-var) (set list-var (if append diff -r fa7844674ed2 -r 513a4815ee5d lisp/ChangeLog --- a/lisp/ChangeLog Mon Feb 25 04:45:41 2008 -0800 +++ b/lisp/ChangeLog Mon Feb 25 04:55:55 2008 -0800 ＠＠ -1,3 +1,8 ＠＠ 2008-02-03 Aidan Kehoe <kehoea＠parhasa +2008-02-25 bpalmer <bpalmer(a)gmail.com&gt; + + * subr.el(add-to-list): add support for `compare-fn' to sync with + emacs. + 2008-02-03 Aidan Kehoe <kehoea(a)parhasard.net&gt; * iso8859-1.el (ascii-case-table): _______________________________________________ XEmacs-Patches mailing list XEmacs-Patches(a)xemacs.org http://calypso.tux.org/cgi-bin/mailman/listinfo/xemacs-patches