source: trunk/j/src/org/armedbear/lisp/deftype.lisp @ 6833

Last change on this file since 6833 was 6833, checked in by piso, 19 years ago

Optional parameters default to * rather than NIL.

File size: 1.6 KB
Line 
1;;; deftype.lisp
2;;;
3;;; Copyright (C) 2003 Peter Graves
4;;; $Id: deftype.lisp,v 1.2 2004-05-19 20:05:39 piso Exp $
5;;;
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.
10;;;
11;;; This program is distributed in the hope that it will be useful,
12;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
13;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14;;; GNU General Public License for more details.
15;;;
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.
19
20(in-package "SYSTEM")
21
22(defmacro deftype (name lambda-list &rest body)
23  ;; Optional parameters default to * rather than NIL.
24  ;; FIXME Extend this code to handle keyword parameters too!
25  (when (memq '&optional lambda-list)
26    (let ((new-lambda-list ())
27          (optionalp nil))
28      (dolist (thing lambda-list)
29        (cond (optionalp
30               (when (symbolp thing)
31                 (setf thing (list thing ''*))))
32              ((eq thing '&optional)
33               (setf optionalp t))
34              ((memq thing lambda-list-keywords)
35               (setf optionalp nil)))
36        (push thing new-lambda-list))
37      (setf lambda-list (nreverse new-lambda-list))))
38  `(progn
39     (setf (get ',name 'deftype-definition) #'(lambda ,lambda-list ,@body))
40     ',name))
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