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eec82323 | 1 | ;;; gnus-range.el --- range and sequence functions for Gnus |
6748645f | 2 | ;; Copyright (C) 1996,97,98 Free Software Foundation, Inc. |
eec82323 | 3 | |
6748645f | 4 | ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org> |
eec82323 LMI |
5 | ;; Keywords: news |
6 | ||
7 | ;; This file is part of GNU Emacs. | |
8 | ||
9 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
10 | ;; it under the terms of the GNU General Public License as published by | |
11 | ;; the Free Software Foundation; either version 2, or (at your option) | |
12 | ;; any later version. | |
13 | ||
14 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
15 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | ;; GNU General Public License for more details. | |
18 | ||
19 | ;; You should have received a copy of the GNU General Public License | |
20 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
21 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | ;; Boston, MA 02111-1307, USA. | |
23 | ||
24 | ;;; Commentary: | |
25 | ||
26 | ;;; Code: | |
27 | ||
7df7482d RS |
28 | (eval-when-compile (require 'cl)) |
29 | ||
6748645f LMI |
30 | (eval-when-compile (require 'cl)) |
31 | ||
eec82323 LMI |
32 | ;;; List and range functions |
33 | ||
34 | (defun gnus-last-element (list) | |
35 | "Return last element of LIST." | |
36 | (while (cdr list) | |
37 | (setq list (cdr list))) | |
38 | (car list)) | |
39 | ||
40 | (defun gnus-copy-sequence (list) | |
41 | "Do a complete, total copy of a list." | |
42 | (let (out) | |
43 | (while (consp list) | |
44 | (if (consp (car list)) | |
45 | (push (gnus-copy-sequence (pop list)) out) | |
46 | (push (pop list) out))) | |
47 | (if list | |
48 | (nconc (nreverse out) list) | |
49 | (nreverse out)))) | |
50 | ||
51 | (defun gnus-set-difference (list1 list2) | |
52 | "Return a list of elements of LIST1 that do not appear in LIST2." | |
53 | (let ((list1 (copy-sequence list1))) | |
54 | (while list2 | |
55 | (setq list1 (delq (car list2) list1)) | |
56 | (setq list2 (cdr list2))) | |
57 | list1)) | |
58 | ||
59 | (defun gnus-sorted-complement (list1 list2) | |
6748645f | 60 | "Return a list of elements that are in LIST1 or LIST2 but not both. |
eec82323 LMI |
61 | Both lists have to be sorted over <." |
62 | (let (out) | |
63 | (if (or (null list1) (null list2)) | |
64 | (or list1 list2) | |
65 | (while (and list1 list2) | |
66 | (cond ((= (car list1) (car list2)) | |
67 | (setq list1 (cdr list1) | |
68 | list2 (cdr list2))) | |
69 | ((< (car list1) (car list2)) | |
70 | (setq out (cons (car list1) out)) | |
71 | (setq list1 (cdr list1))) | |
72 | (t | |
73 | (setq out (cons (car list2) out)) | |
74 | (setq list2 (cdr list2))))) | |
75 | (nconc (nreverse out) (or list1 list2))))) | |
76 | ||
77 | (defun gnus-intersection (list1 list2) | |
78 | (let ((result nil)) | |
79 | (while list2 | |
80 | (when (memq (car list2) list1) | |
81 | (setq result (cons (car list2) result))) | |
82 | (setq list2 (cdr list2))) | |
83 | result)) | |
84 | ||
85 | (defun gnus-sorted-intersection (list1 list2) | |
86 | ;; LIST1 and LIST2 have to be sorted over <. | |
87 | (let (out) | |
88 | (while (and list1 list2) | |
89 | (cond ((= (car list1) (car list2)) | |
90 | (setq out (cons (car list1) out) | |
91 | list1 (cdr list1) | |
92 | list2 (cdr list2))) | |
93 | ((< (car list1) (car list2)) | |
94 | (setq list1 (cdr list1))) | |
95 | (t | |
96 | (setq list2 (cdr list2))))) | |
97 | (nreverse out))) | |
98 | ||
99 | (defun gnus-set-sorted-intersection (list1 list2) | |
100 | ;; LIST1 and LIST2 have to be sorted over <. | |
101 | ;; This function modifies LIST1. | |
102 | (let* ((top (cons nil list1)) | |
103 | (prev top)) | |
104 | (while (and list1 list2) | |
105 | (cond ((= (car list1) (car list2)) | |
106 | (setq prev list1 | |
107 | list1 (cdr list1) | |
108 | list2 (cdr list2))) | |
109 | ((< (car list1) (car list2)) | |
110 | (setcdr prev (cdr list1)) | |
111 | (setq list1 (cdr list1))) | |
112 | (t | |
113 | (setq list2 (cdr list2))))) | |
114 | (setcdr prev nil) | |
115 | (cdr top))) | |
116 | ||
117 | (defun gnus-compress-sequence (numbers &optional always-list) | |
118 | "Convert list of numbers to a list of ranges or a single range. | |
119 | If ALWAYS-LIST is non-nil, this function will always release a list of | |
120 | ranges." | |
121 | (let* ((first (car numbers)) | |
122 | (last (car numbers)) | |
123 | result) | |
124 | (if (null numbers) | |
125 | nil | |
126 | (if (not (listp (cdr numbers))) | |
127 | numbers | |
128 | (while numbers | |
129 | (cond ((= last (car numbers)) nil) ;Omit duplicated number | |
130 | ((= (1+ last) (car numbers)) ;Still in sequence | |
131 | (setq last (car numbers))) | |
132 | (t ;End of one sequence | |
133 | (setq result | |
134 | (cons (if (= first last) first | |
135 | (cons first last)) | |
136 | result)) | |
137 | (setq first (car numbers)) | |
138 | (setq last (car numbers)))) | |
139 | (setq numbers (cdr numbers))) | |
140 | (if (and (not always-list) (null result)) | |
141 | (if (= first last) (list first) (cons first last)) | |
142 | (nreverse (cons (if (= first last) first (cons first last)) | |
143 | result))))))) | |
144 | ||
145 | (defalias 'gnus-uncompress-sequence 'gnus-uncompress-range) | |
146 | (defun gnus-uncompress-range (ranges) | |
147 | "Expand a list of ranges into a list of numbers. | |
148 | RANGES is either a single range on the form `(num . num)' or a list of | |
149 | these ranges." | |
150 | (let (first last result) | |
151 | (cond | |
152 | ((null ranges) | |
153 | nil) | |
154 | ((not (listp (cdr ranges))) | |
155 | (setq first (car ranges)) | |
156 | (setq last (cdr ranges)) | |
157 | (while (<= first last) | |
158 | (setq result (cons first result)) | |
159 | (setq first (1+ first))) | |
160 | (nreverse result)) | |
161 | (t | |
162 | (while ranges | |
163 | (if (atom (car ranges)) | |
164 | (when (numberp (car ranges)) | |
165 | (setq result (cons (car ranges) result))) | |
166 | (setq first (caar ranges)) | |
167 | (setq last (cdar ranges)) | |
168 | (while (<= first last) | |
169 | (setq result (cons first result)) | |
170 | (setq first (1+ first)))) | |
171 | (setq ranges (cdr ranges))) | |
172 | (nreverse result))))) | |
173 | ||
174 | (defun gnus-add-to-range (ranges list) | |
175 | "Return a list of ranges that has all articles from both RANGES and LIST. | |
176 | Note: LIST has to be sorted over `<'." | |
177 | (if (not ranges) | |
178 | (gnus-compress-sequence list t) | |
179 | (setq list (copy-sequence list)) | |
180 | (unless (listp (cdr ranges)) | |
181 | (setq ranges (list ranges))) | |
182 | (let ((out ranges) | |
183 | ilist lowest highest temp) | |
184 | (while (and ranges list) | |
185 | (setq ilist list) | |
186 | (setq lowest (or (and (atom (car ranges)) (car ranges)) | |
187 | (caar ranges))) | |
188 | (while (and list (cdr list) (< (cadr list) lowest)) | |
189 | (setq list (cdr list))) | |
190 | (when (< (car ilist) lowest) | |
191 | (setq temp list) | |
192 | (setq list (cdr list)) | |
193 | (setcdr temp nil) | |
194 | (setq out (nconc (gnus-compress-sequence ilist t) out))) | |
195 | (setq highest (or (and (atom (car ranges)) (car ranges)) | |
196 | (cdar ranges))) | |
197 | (while (and list (<= (car list) highest)) | |
198 | (setq list (cdr list))) | |
199 | (setq ranges (cdr ranges))) | |
200 | (when list | |
201 | (setq out (nconc (gnus-compress-sequence list t) out))) | |
202 | (setq out (sort out (lambda (r1 r2) | |
203 | (< (or (and (atom r1) r1) (car r1)) | |
204 | (or (and (atom r2) r2) (car r2)))))) | |
205 | (setq ranges out) | |
206 | (while ranges | |
207 | (if (atom (car ranges)) | |
208 | (when (cdr ranges) | |
209 | (if (atom (cadr ranges)) | |
210 | (when (= (1+ (car ranges)) (cadr ranges)) | |
211 | (setcar ranges (cons (car ranges) | |
212 | (cadr ranges))) | |
213 | (setcdr ranges (cddr ranges))) | |
a8151ef7 | 214 | (when (= (1+ (car ranges)) (caadr ranges)) |
eec82323 LMI |
215 | (setcar (cadr ranges) (car ranges)) |
216 | (setcar ranges (cadr ranges)) | |
217 | (setcdr ranges (cddr ranges))))) | |
218 | (when (cdr ranges) | |
219 | (if (atom (cadr ranges)) | |
220 | (when (= (1+ (cdar ranges)) (cadr ranges)) | |
221 | (setcdr (car ranges) (cadr ranges)) | |
222 | (setcdr ranges (cddr ranges))) | |
a8151ef7 LMI |
223 | (when (= (1+ (cdar ranges)) (caadr ranges)) |
224 | (setcdr (car ranges) (cdadr ranges)) | |
eec82323 LMI |
225 | (setcdr ranges (cddr ranges)))))) |
226 | (setq ranges (cdr ranges))) | |
227 | out))) | |
228 | ||
229 | (defun gnus-remove-from-range (ranges list) | |
230 | "Return a list of ranges that has all articles from LIST removed from RANGES. | |
231 | Note: LIST has to be sorted over `<'." | |
232 | ;; !!! This function shouldn't look like this, but I've got a headache. | |
233 | (gnus-compress-sequence | |
234 | (gnus-sorted-complement | |
235 | (gnus-uncompress-range ranges) list))) | |
236 | ||
237 | (defun gnus-member-of-range (number ranges) | |
238 | (if (not (listp (cdr ranges))) | |
239 | (and (>= number (car ranges)) | |
240 | (<= number (cdr ranges))) | |
241 | (let ((not-stop t)) | |
242 | (while (and ranges | |
243 | (if (numberp (car ranges)) | |
244 | (>= number (car ranges)) | |
245 | (>= number (caar ranges))) | |
246 | not-stop) | |
247 | (when (if (numberp (car ranges)) | |
248 | (= number (car ranges)) | |
249 | (and (>= number (caar ranges)) | |
250 | (<= number (cdar ranges)))) | |
251 | (setq not-stop nil)) | |
252 | (setq ranges (cdr ranges))) | |
253 | (not not-stop)))) | |
254 | ||
255 | (defun gnus-range-length (range) | |
256 | "Return the length RANGE would have if uncompressed." | |
257 | (length (gnus-uncompress-range range))) | |
258 | ||
259 | (defun gnus-sublist-p (list sublist) | |
260 | "Test whether all elements in SUBLIST are members of LIST." | |
261 | (let ((sublistp t)) | |
262 | (while sublist | |
263 | (unless (memq (pop sublist) list) | |
264 | (setq sublistp nil | |
265 | sublist nil))) | |
266 | sublistp)) | |
267 | ||
268 | (defun gnus-range-add (range1 range2) | |
269 | "Add RANGE2 to RANGE1 destructively." | |
270 | (cond | |
271 | ;; If either are nil, then the job is quite easy. | |
272 | ((or (null range1) (null range2)) | |
273 | (or range1 range2)) | |
274 | (t | |
275 | ;; I don't like thinking. | |
276 | (gnus-compress-sequence | |
277 | (sort | |
278 | (nconc | |
279 | (gnus-uncompress-range range1) | |
280 | (gnus-uncompress-range range2)) | |
281 | '<))))) | |
282 | ||
283 | (provide 'gnus-range) | |
284 | ||
285 | ;;; gnus-range.el ends here |