1 ;;; srfi-111.scm -- SRFI 111 Boxes
3 ;; Copyright (C) 2014 Free Software Foundation, Inc.
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.
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.
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
19 (define-module (srfi srfi-111)
20 #:use-module (srfi srfi-9)
21 #:use-module (srfi srfi-9 gnu)
22 #:export (box box? unbox set-box!))
24 (cond-expand-provide (current-module) '(srfi-111))
26 (define-record-type <box>
29 (value unbox set-box!))
31 (set-record-type-printer! <box>
33 (display "#<box " port)
34 (display (number->string (object-address box) 16) port)
36 (write (unbox box) port)