source: trunk/j/src/org/armedbear/lisp/assoc.lisp @ 4371

;;; assoc.lisp
;;;
;;; Copyright (C) 2003 Peter Graves
;;; $Id: assoc.lisp,v 1.4 2003-10-14 16:04:29 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.

;;; From CMUCL.

(in-package "SYSTEM")

(defmacro assoc-guts (test-guy)
  `(do ((alist alist (cdr alist)))
       ((endp alist))
     (if (car alist)
   (if ,test-guy (return (car alist))))))

(defun assoc (item alist &key key test test-not)
  (cond (test
   (if key
       (assoc-guts (funcall test item (funcall key (caar alist))))
       (assoc-guts (funcall test item (caar alist)))))
  (test-not
   (if key
       (assoc-guts (not (funcall test-not item
               (funcall key (caar alist)))))
       (assoc-guts (not (funcall test-not item (caar alist))))))
  (t
   (if key
       (assoc-guts (eql item (funcall key (caar alist))))
       (assoc-guts (eql item (caar alist)))))))

(defun assoc-if (predicate alist &key key)
  (if key
      (assoc-guts (funcall predicate (funcall key (caar alist))))
      (assoc-guts (funcall predicate (caar alist)))))

(defun assoc-if-not (predicate alist &key key)
  (if key
      (assoc-guts (not (funcall predicate (funcall key (caar alist)))))
      (assoc-guts (not (funcall predicate (caar alist))))))

(defun rassoc (item alist &key key test test-not)
  (cond (test
   (if key
       (assoc-guts (funcall test item (funcall key (cdar alist))))
       (assoc-guts (funcall test item (cdar alist)))))
  (test-not
   (if key
       (assoc-guts (not (funcall test-not item
               (funcall key (cdar alist)))))
       (assoc-guts (not (funcall test-not item (cdar alist))))))
  (t
   (if key
       (assoc-guts (eql item (funcall key (cdar alist))))
       (assoc-guts (eql item (cdar alist)))))))

(defun rassoc-if (predicate alist &key key)
  (if key
      (assoc-guts (funcall predicate (funcall key (cdar alist))))
      (assoc-guts (funcall predicate (cdar alist)))))

(defun rassoc-if-not (predicate alist &key key)
  (if key
      (assoc-guts (not (funcall predicate (funcall key (cdar alist)))))
      (assoc-guts (not (funcall predicate (cdar alist))))))

(defun acons (key datum alist)
  (cons (cons key datum) alist))

(defun pairlis (keys data &optional (alist '()))
  (do ((x keys (cdr x))
       (y data (cdr y)))
      ((and (endp x) (endp y)) alist)
    (if (or (endp x) (endp y))
  (error "the lists of keys and data are of unequal length"))
    (setq alist (acons (car x) (car y) alist))))

(defun copy-alist (alist)
  (if (atom alist)
      alist
      (let ((result
       (cons (if (atom (car alist))
           (car alist)
           (cons (caar alist) (cdar alist)) )
       nil)))
  (do ((x (cdr alist) (cdr x))
       (splice result
         (cdr (rplacd splice
          (cons
           (if (atom (car x))
               (car x)
               (cons (caar x) (cdar x)))
           nil)))))
            ;; Non-null terminated alist done here.
            ((atom x)
             (unless (null x)
               (rplacd splice x))))
  result)))