1;;;; List functions not provided in R5RS or srfi-1
2
3;;; Copyright (C) 2003, 2006 Free Software Foundation, Inc.
4;;;
5;;;; This library is free software; you can redistribute it and/or
6;;;; modify it under the terms of the GNU Lesser General Public
7;;;; License as published by the Free Software Foundation; either
8;;;; version 3 of the License, or (at your option) any later version.
9;;;;
10;;;; This library is distributed in the hope that it will be useful,
11;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
12;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13;;;; Lesser General Public License for more details.
14;;;;
15;;;; You should have received a copy of the GNU Lesser General Public
16;;;; License along with this library; if not, write to the Free Software
17;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18
19(define-module (ice-9 list)
20  :export (rassoc rassv rassq))
21
22(define (generic-rassoc key alist =)
23  (let loop ((ls alist))
24      (and (not (null? ls))
25	   (if (= key (cdar ls))
26	       (car ls)
27	       (loop (cdr ls))))))
28
29(define (rassoc key alist . =)
30  (generic-rassoc key alist (if (null? =) equal? (car =))))
31
32(define (rassv key alist)
33  (generic-rassoc key alist eqv?))
34
35(define (rassq key alist)
36  (generic-rassoc key alist eq?))
37