Mercurial > hg > xemacs-beta

comparison lisp/utils/ring.el @ 2:ac2d302a0011 r19-15b2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Import from CVS: tag r19-15b2
author cvs
date Mon, 13 Aug 2007 08:46:35 +0200
parents 376386a54a3c
children 2d532a89d707
comparison
equal deleted inserted replaced
1:c0c6a60d29db 2:ac2d302a0011
3 ;; Copyright (C) 1992 Free Software Foundation, Inc. 3 ;; Copyright (C) 1992 Free Software Foundation, Inc.
4 4
5 ;; Maintainer: FSF 5 ;; Maintainer: FSF
6 ;; Keywords: extensions 6 ;; Keywords: extensions
7 7
8 ;; This file is part of GNU Emacs. 8 ;; This file is part of XEmacs.
9 9
10 ;; GNU Emacs is free software; you can redistribute it and/or modify 10 ;; XEmacs is free software; you can redistribute it and/or modify it
11 ;; it under the terms of the GNU General Public License as published by 11 ;; under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option) 12 ;; the Free Software Foundation; either version 2, or (at your option)
13 ;; any later version. 13 ;; any later version.
14 14
15 ;; GNU Emacs is distributed in the hope that it will be useful, 15 ;; XEmacs is distributed in the hope that it will be useful, but
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of 16 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 ;; GNU General Public License for more details. 18 ;; General Public License for more details.
19 19
20 ;; You should have received a copy of the GNU General Public License 20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to 21 ;; along with XEmacs; see the file COPYING. If not, write to the Free
22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 22 ;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
23 ;; 02111-1307, USA.
23 24
24 ;;; Synched up with: FSF 19.30. 25 ;;; Synched up with: FSF 19.34.
25 26
26 ;;; Commentary: 27 ;;; Commentary:
27 28
28 ;;; This code defines a ring data structure. A ring is a 29 ;; This code defines a ring data structure. A ring is a
29 ;;; (hd-index length . vector) 30 ;; (hd-index length . vector)
30 ;;; list. You can insert to, remove from, and rotate a ring. When the ring 31 ;; list. You can insert to, remove from, and rotate a ring. When the ring
31 ;;; fills up, insertions cause the oldest elts to be quietly dropped. 32 ;; fills up, insertions cause the oldest elts to be quietly dropped.
32 ;;; 33 ;;
33 ;;; In ring-ref, 0 is the index of the newest element. Higher indexes 34 ;; In ring-ref, 0 is the index of the newest element. Higher indexes
34 ;;; correspond to older elements until they wrap. 35 ;; correspond to older elements until they wrap.
35 ;;; 36 ;;
36 ;;; hd-index = index of the newest item on the ring. 37 ;; hd-index = index of the newest item on the ring.
37 ;;; length = number of ring items. 38 ;; length = number of ring items.
38 ;;; 39 ;;
39 ;;; These functions are used by the input history mechanism, but they can 40 ;; These functions are used by the input history mechanism, but they can
40 ;;; be used for other purposes as well. 41 ;; be used for other purposes as well.
41 42
42 ;;; Code: 43 ;;; Code:
43 44
45 ;; XEmacs change
44 ;;;###autoload 46 ;;;###autoload
45 (defun ringp (x) 47 (defun ringp (x)
46 "Returns t if X is a ring; nil otherwise." 48 "Returns t if X is a ring; nil otherwise."
47 (and (consp x) (integerp (car x)) 49 (and (consp x) (integerp (car x))
48 (consp (cdr x)) (integerp (car (cdr x))) 50 (consp (cdr x)) (integerp (car (cdr x)))
49 (vectorp (cdr (cdr x))))) 51 (vectorp (cdr (cdr x)))))
50 52
53 ;; XEmacs change
51 ;;;###autoload 54 ;;;###autoload
52 (define-obsolete-function-alias 'ring-p 'ringp) 55 (define-obsolete-function-alias 'ring-p 'ringp)
53 56
54 ;;;###autoload 57 ;;;###autoload
55 (defun make-ring (size) 58 (defun make-ring (size)