module/rnrs/lists.scm

   1 ;;; lists.scm --- The R6RS list utilities library
   2
   3 ;;      Copyright (C) 2010 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 \f
  19
  20 (library (rnrs lists (6))
  21   (export find for-all exists filter partition fold-left fold-right remp remove
  22           remv remq memp member memv memq assp assoc assv assq cons*)
  23   (import (rnrs base (6))
  24           (only (guile) filter member memv memq assoc assv assq cons*)
  25           (rename (only (srfi srfi-1) any
  26                                       every
  27                                       remove
  28                                       member
  29                                       assoc
  30                                       find
  31                                       partition
  32                                       fold-right
  33                                       filter-map)
  34                   (any exists)
  35                   (every for-all)
  36                   (remove remp)
  37
  38                   (member memp-internal)
  39                   (assoc assp-internal)))
  40
  41   (define (fold-left combine nil list . lists)
  42     (define (fold nil lists)
  43       (if (exists null? lists)
  44           nil
  45           (fold (apply combine nil (map car lists))
  46                 (map cdr lists))))
  47     (fold nil (cons list lists)))
  48
  49   (define (remove obj list) (remp (lambda (elt) (equal? obj elt)) list))
  50   (define (remv obj list) (remp (lambda (elt) (eqv? obj elt)) list))
  51   (define (remq obj list) (remp (lambda (elt) (eq? obj elt)) list))
  52
  53   (define (memp pred list) (memp-internal #f list (lambda (x y) (pred y))))
  54   (define (assp pred list) (assp-internal #f list (lambda (x y) (pred y))))
  55 )