source: trunk/abcl/src/org/armedbear/lisp/delete-duplicates.lisp @ 14207

Last change on this file since 14207 was 12516, checked in by astalla, 11 years ago

Support for user-extensible sequences, adapted from SBCL.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 3.6 KB
Line 
1;;; delete-duplicates.lisp
2;;;
3;;; Copyright (C) 2003 Peter Graves
4;;; $Id: delete-duplicates.lisp 12516 2010-03-03 21:05:41Z astalla $
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;;; 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.
31
32(in-package "SYSTEM")
33
34(require "EXTENSIBLE-SEQUENCES-BASE")
35
36;;; From CMUCL.
37
38(defun list-delete-duplicates* (list test test-not key from-end start end)
39  (let ((handle (cons nil list)))
40    (do ((current (nthcdr start list) (cdr current))
41   (previous (nthcdr start handle))
42   (index start (1+ index)))
43      ((or (and end (= index end)) (null current))
44       (cdr handle))
45      (if (do ((x (if from-end
46          (nthcdr (1+ start) handle)
47          (cdr current))
48      (cdr x))
49         (i (1+ index) (1+ i)))
50            ((or (null x)
51                 (and (not from-end) end (= i end))
52                 (eq x current))
53             nil)
54      (if (if test-not
55        (not (funcall test-not
56          (sys::apply-key key (car current))
57          (sys::apply-key key (car x))))
58        (funcall test
59           (sys::apply-key key (car current))
60           (sys::apply-key key (car x))))
61    (return t)))
62    (rplacd previous (cdr current))
63    (setq previous (cdr previous))))))
64
65
66(defun vector-delete-duplicates* (vector test test-not key from-end start end
67           &optional (length (length vector)))
68  (when (null end) (setf end (length vector)))
69  (do ((index start (1+ index))
70       (jndex start))
71    ((= index end)
72     (do ((index index (1+ index))    ; copy the rest of the vector
73          (jndex jndex (1+ jndex)))
74       ((= index length)
75        (shrink-vector vector jndex)
76        vector)
77       (setf (aref vector jndex) (aref vector index))))
78    (setf (aref vector jndex) (aref vector index))
79    (unless (position (sys::apply-key key (aref vector index)) vector :key key
80          :start (if from-end start (1+ index)) :test test
81          :end (if from-end jndex end) :test-not test-not)
82      (setq jndex (1+ jndex)))))
83
84(defun delete-duplicates (sequence &rest args &key (test #'eql) test-not
85        (start 0) from-end end key)
86  (sequence::seq-dispatch sequence
87    (if sequence
88  (list-delete-duplicates* sequence test test-not key from-end start end))
89    (vector-delete-duplicates* sequence test test-not key from-end start end)
90    (apply #'sequence:delete-duplicates sequence args)))
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