source: trunk/abcl/src/org/armedbear/lisp/multiple-value-bind.lisp @ 14207

Last change on this file since 14207 was 11391, checked in by vvoutilainen, 13 years ago

ABCL license is GPL + Classpath exception. This was intended
by Peter Graves, the original author. For reference, see

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 2.4 KB
1;;; multiple-value-bind.lisp
3;;; Copyright (C) 2004 Peter Graves
4;;; $Id: multiple-value-bind.lisp 11391 2008-11-15 22:38:34Z vvoutilainen $
6;;; This program is free software; you can redistribute it and/or
7;;; modify it under the terms of the GNU General Public License
8;;; as published by the Free Software Foundation; either version 2
9;;; of the License, or (at your option) any later version.
11;;; This program is distributed in the hope that it will be useful,
12;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
14;;; GNU General Public License for more details.
16;;; You should have received a copy of the GNU General Public License
17;;; along with this program; if not, write to the Free Software
18;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
20;;; As a special exception, the copyright holders of this library give you
21;;; permission to link this library with independent modules to produce an
22;;; executable, regardless of the license terms of these independent
23;;; modules, and to copy and distribute the resulting executable under
24;;; terms of your choice, provided that you also meet, for each linked
25;;; independent module, the terms and conditions of the license of that
26;;; module.  An independent module is a module which is not derived from
27;;; or based on this library.  If you modify this library, you may extend
28;;; this exception to your version of the library, but you are not
29;;; obligated to do so.  If you do not wish to do so, delete this
30;;; exception statement from your version.
32;;; Adapted from CMUCL.
34(in-package "SYSTEM")
36;; The traditional implementation of M-V-B in terms of M-V-C. ABCL implements
37;; M-V-B as a special form in the interpreter, and ABCL's compiler handles it
38;; specifically too, so this code is only here to support code walkers and the
39;; like, as required by ANSI.
40(defmacro multiple-value-bind (varlist value-form &body body)
41  (unless (and (listp varlist) (every #'symbolp varlist))
42    (error 'program-error
43           :format-control "Variable list is not a list of symbols: ~S."
44           :format-arguments (list varlist)))
45  (if (= (length varlist) 1)
46      `(let ((,(car varlist) ,value-form))
47   ,@body)
48      (let ((ignore (gensym)))
49  `(multiple-value-call #'(lambda (&optional ,@(mapcar #'list varlist) &rest ,ignore)
50                                 (declare (ignore ,ignore))
51                                 ,@body)
52                              ,value-form))))
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