;;; adjoin.lisp
;;;
;;; Copyright (C) 2003 Peter Graves
;;; $Id: adjoin.lisp,v 1.3 2003/08/01 01:22:14 piso Exp $
;;;
;;; This program is free software; you can redistribute it and/or
;;; modify it under the terms of the GNU General Public License
;;; as published by the Free Software Foundation; either version 2
;;; of the License, or (at your option) any later version.
;;;
;;; This program is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program; if not, write to the Free Software
;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

(defun adjoin (item list &key key (test #'eql testp) (test-not nil notp))
  (when (and testp notp)
    (error "test and test-not both supplied"))
  (if (let ((key-val (sys::apply-key key item)))
	(if notp
	    (member key-val list :test-not test-not :key key)
	    (member key-val list :test test :key key)))
      list
      (cons item list)))
