;;; border.el
;;;
;;; Copyright (C) 1997, 1998, 2004, 2007, 2008 Thien-Thi Nguyen
;;;
;;; This file is part of ttn's personal elisp library, released under
;;; the terms of the GNU General Public License as published by the
;;; Free Software Foundation; either version 3, or (at your option) any
;;; later version.  There is NO WARRANTY.  See file COPYING for details.

;;; Description: Given a list and break element, return "border" list.
;;; E.g., (border 3 '(1 2 3 4 5)) => (2 3 4 5).
;;; In conjunction w/ setcdr, this is useful for list splitting.

;;;###autoload
(defun border (elem lst)
  "Find sublist, using ELEM of LST, where ELEM is the cadr.  Test w/ equal."
  (and (consp lst)
       (consp (cdr lst))
       (or (and (equal elem (cadr lst))
                lst)
           (border elem (cdr lst)))))

(provide 'border)

;;; border.el ends here