summaryrefslogtreecommitdiff
path: root/lisp/gnus/gnus-range.el
blob: 223a32e33b3be99f6576050e57280aaa1b1af9fb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
;;; gnus-range.el --- range and sequence functions for Gnus

;; Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;;; Code:

(eval-when-compile (require 'cl))

;;; List and range functions

(defun gnus-last-element (list)
  "Return last element of LIST."
  (while (cdr list)
    (setq list (cdr list)))
  (car list))

(defun gnus-copy-sequence (list)
  "Do a complete, total copy of a list."
  (let (out)
    (while (consp list)
      (if (consp (car list))
	  (push (gnus-copy-sequence (pop list)) out)
	(push (pop list) out)))
    (if list
	(nconc (nreverse out) list)
      (nreverse out))))

(defun gnus-set-difference (list1 list2)
  "Return a list of elements of LIST1 that do not appear in LIST2."
  (let ((list1 (copy-sequence list1)))
    (while list2
      (setq list1 (delq (car list2) list1))
      (setq list2 (cdr list2)))
    list1))

(defun gnus-sorted-complement (list1 list2)
  "Return a list of elements that are in LIST1 or LIST2 but not both.
Both lists have to be sorted over <."
  (let (out)
    (if (or (null list1) (null list2))
	(or list1 list2)
      (while (and list1 list2)
	(cond ((= (car list1) (car list2))
	       (setq list1 (cdr list1)
		     list2 (cdr list2)))
	      ((< (car list1) (car list2))
	       (setq out (cons (car list1) out))
	       (setq list1 (cdr list1)))
	      (t
	       (setq out (cons (car list2) out))
	       (setq list2 (cdr list2)))))
      (nconc (nreverse out) (or list1 list2)))))

(defun gnus-intersection (list1 list2)
  (let ((result nil))
    (while list2
      (when (memq (car list2) list1)
	(setq result (cons (car list2) result)))
      (setq list2 (cdr list2)))
    result))

(defun gnus-sorted-intersection (list1 list2)
  ;; LIST1 and LIST2 have to be sorted over <.
  (let (out)
    (while (and list1 list2)
      (cond ((= (car list1) (car list2))
	     (setq out (cons (car list1) out)
		   list1 (cdr list1)
		   list2 (cdr list2)))
	    ((< (car list1) (car list2))
	     (setq list1 (cdr list1)))
	    (t
	     (setq list2 (cdr list2)))))
    (nreverse out)))

(defun gnus-set-sorted-intersection (list1 list2)
  ;; LIST1 and LIST2 have to be sorted over <.
  ;; This function modifies LIST1.
  (let* ((top (cons nil list1))
	 (prev top))
    (while (and list1 list2)
      (cond ((= (car list1) (car list2))
	     (setq prev list1
		   list1 (cdr list1)
		   list2 (cdr list2)))
	    ((< (car list1) (car list2))
	     (setcdr prev (cdr list1))
	     (setq list1 (cdr list1)))
	    (t
	     (setq list2 (cdr list2)))))
    (setcdr prev nil)
    (cdr top)))

(defun gnus-compress-sequence (numbers &optional always-list)
  "Convert list of numbers to a list of ranges or a single range.
If ALWAYS-LIST is non-nil, this function will always release a list of
ranges."
  (let* ((first (car numbers))
	 (last (car numbers))
	 result)
    (if (null numbers)
	nil
      (if (not (listp (cdr numbers)))
	  numbers
	(while numbers
	  (cond ((= last (car numbers)) nil) ;Omit duplicated number
		((= (1+ last) (car numbers)) ;Still in sequence
		 (setq last (car numbers)))
		(t			;End of one sequence
		 (setq result
		       (cons (if (= first last) first
			       (cons first last))
			     result))
		 (setq first (car numbers))
		 (setq last  (car numbers))))
	  (setq numbers (cdr numbers)))
	(if (and (not always-list) (null result))
	    (if (= first last) (list first) (cons first last))
	  (nreverse (cons (if (= first last) first (cons first last))
			  result)))))))

(defalias 'gnus-uncompress-sequence 'gnus-uncompress-range)
(defun gnus-uncompress-range (ranges)
  "Expand a list of ranges into a list of numbers.
RANGES is either a single range on the form `(num . num)' or a list of
these ranges."
  (let (first last result)
    (cond
     ((null ranges)
      nil)
     ((not (listp (cdr ranges)))
      (setq first (car ranges))
      (setq last (cdr ranges))
      (while (<= first last)
	(setq result (cons first result))
	(setq first (1+ first)))
      (nreverse result))
     (t
      (while ranges
	(if (atom (car ranges))
	    (when (numberp (car ranges))
	      (setq result (cons (car ranges) result)))
	  (setq first (caar ranges))
	  (setq last  (cdar ranges))
	  (while (<= first last)
	    (setq result (cons first result))
	    (setq first (1+ first))))
	(setq ranges (cdr ranges)))
      (nreverse result)))))

(defun gnus-add-to-range (ranges list)
  "Return a list of ranges that has all articles from both RANGES and LIST.
Note: LIST has to be sorted over `<'."
  (if (not ranges)
      (gnus-compress-sequence list t)
    (setq list (copy-sequence list))
    (unless (listp (cdr ranges))
      (setq ranges (list ranges)))
    (let ((out ranges)
	  ilist lowest highest temp)
      (while (and ranges list)
	(setq ilist list)
	(setq lowest (or (and (atom (car ranges)) (car ranges))
			 (caar ranges)))
	(while (and list (cdr list) (< (cadr list) lowest))
	  (setq list (cdr list)))
	(when (< (car ilist) lowest)
	  (setq temp list)
	  (setq list (cdr list))
	  (setcdr temp nil)
	  (setq out (nconc (gnus-compress-sequence ilist t) out)))
	(setq highest (or (and (atom (car ranges)) (car ranges))
			  (cdar ranges)))
	(while (and list (<= (car list) highest))
	  (setq list (cdr list)))
	(setq ranges (cdr ranges)))
      (when list
	(setq out (nconc (gnus-compress-sequence list t) out)))
      (setq out (sort out (lambda (r1 r2)
			    (< (or (and (atom r1) r1) (car r1))
			       (or (and (atom r2) r2) (car r2))))))
      (setq ranges out)
      (while ranges
	(if (atom (car ranges))
	    (when (cdr ranges)
	      (if (atom (cadr ranges))
		  (when (= (1+ (car ranges)) (cadr ranges))
		    (setcar ranges (cons (car ranges)
					 (cadr ranges)))
		    (setcdr ranges (cddr ranges)))
		(when (= (1+ (car ranges)) (caadr ranges))
		  (setcar (cadr ranges) (car ranges))
		  (setcar ranges (cadr ranges))
		  (setcdr ranges (cddr ranges)))))
	  (when (cdr ranges)
	    (if (atom (cadr ranges))
		(when (= (1+ (cdar ranges)) (cadr ranges))
		  (setcdr (car ranges) (cadr ranges))
		  (setcdr ranges (cddr ranges)))
	      (when (= (1+ (cdar ranges)) (caadr ranges))
		(setcdr (car ranges) (cdadr ranges))
		(setcdr ranges (cddr ranges))))))
	(setq ranges (cdr ranges)))
      out)))

(defun gnus-remove-from-range (range1 range2)
  "Return a range that has all articles from RANGE2 removed from RANGE1.
The returned range is always a list.  RANGE2 can also be a unsorted
list of articles.  RANGE1 is modified by side effects, RANGE2 is not
modified."
  (if (or (null range1) (null range2))
      range1
    (let (out r1 r2 r1_min r1_max r2_min r2_max
	      (range2 (gnus-copy-sequence range2)))
      (setq range1 (if (listp (cdr range1)) range1 (list range1))
	    range2 (sort (if (listp (cdr range2)) range2 (list range2))
			 (lambda (e1 e2)
			   (< (if (consp e1) (car e1) e1)
			      (if (consp e2) (car e2) e2))))
	    r1 (car range1)
	    r2 (car range2)
	    r1_min (if (consp r1) (car r1) r1)
	    r1_max (if (consp r1) (cdr r1) r1)
	    r2_min (if (consp r2) (car r2) r2)
	    r2_max (if (consp r2) (cdr r2) r2))
      (while (and range1 range2)
	(cond ((< r2_max r1_min)	; r2 < r1
	       (pop range2)
	       (setq r2 (car range2)
		     r2_min (if (consp r2) (car r2) r2)
		     r2_max (if (consp r2) (cdr r2) r2)))
	      ((and (<= r2_min r1_min) (<= r1_max r2_max)) ; r2 overlap r1
	       (pop range1)
	       (setq r1 (car range1)
		     r1_min (if (consp r1) (car r1) r1)
		     r1_max (if (consp r1) (cdr r1) r1)))
	      ((and (<= r2_min r1_min) (<= r2_max r1_max)) ; r2 overlap min r1
	       (pop range2)
	       (setq r1_min (1+ r2_max)
		     r2 (car range2)
		     r2_min (if (consp r2) (car r2) r2)
		     r2_max (if (consp r2) (cdr r2) r2)))
	      ((and (<= r1_min r2_min) (<= r2_max r1_max)) ; r2 contained in r1
	       (if (eq r1_min (1- r2_min))
		   (push r1_min out)
		 (push (cons r1_min (1- r2_min)) out))
	       (pop range2)
	       (if (< r2_max r1_max)	; finished with r1?
		   (setq r1_min (1+ r2_max))
		 (pop range1)
		 (setq r1 (car range1)
		       r1_min (if (consp r1) (car r1) r1)
		       r1_max (if (consp r1) (cdr r1) r1)))
	       (setq r2 (car range2)
		     r2_min (if (consp r2) (car r2) r2)
		     r2_max (if (consp r2) (cdr r2) r2)))
	      ((and (<= r2_min r1_max) (<= r1_max r2_max)) ; r2 overlap max r1
	       (if (eq r1_min (1- r2_min))
		   (push r1_min out)
		 (push (cons r1_min (1- r2_min)) out))
	       (pop range1)
	       (setq r1 (car range1)
		     r1_min (if (consp r1) (car r1) r1)
		     r1_max (if (consp r1) (cdr r1) r1)))
	      ((< r1_max r2_min)	; r2 > r1
	       (pop range1)
	       (if (eq r1_min r1_max)
		   (push r1_min out)
		 (push (cons r1_min r1_max) out))
	       (setq r1 (car range1)
		     r1_min (if (consp r1) (car r1) r1)
		     r1_max (if (consp r1) (cdr r1) r1)))))
      (when r1
	(if (eq r1_min r1_max)
	    (push r1_min out)
	  (push (cons r1_min r1_max) out))
	(pop range1))
      (while range1
	(push (pop range1) out))
      (nreverse out))))

(defun gnus-member-of-range (number ranges)
  (if (not (listp (cdr ranges)))
      (and (>= number (car ranges))
	   (<= number (cdr ranges)))
    (let ((not-stop t))
      (while (and ranges
		  (if (numberp (car ranges))
		      (>= number (car ranges))
		    (>= number (caar ranges)))
		  not-stop)
	(when (if (numberp (car ranges))
		  (= number (car ranges))
		(and (>= number (caar ranges))
		     (<= number (cdar ranges))))
	  (setq not-stop nil))
	(setq ranges (cdr ranges)))
      (not not-stop))))

(defun gnus-range-length (range)
  "Return the length RANGE would have if uncompressed."
  (length (gnus-uncompress-range range)))

(defun gnus-sublist-p (list sublist)
  "Test whether all elements in SUBLIST are members of LIST."
  (let ((sublistp t))
    (while sublist
      (unless (memq (pop sublist) list)
	(setq sublistp nil
	      sublist nil)))
    sublistp))

(defun gnus-range-add (range1 range2)
  "Add RANGE2 to RANGE1 (nondestructively)."
  (unless (listp (cdr range1))
    (setq range1 (list range1)))
  (unless (listp (cdr range2))
    (setq range2 (list range2)))
  (let ((item1 (pop range1))
	(item2 (pop range2))
	range item selector)
    (while (or item1 item2)
      (setq selector
	    (cond 
	     ((null item1) nil)
	     ((null item2) t)
	     ((and (numberp item1) (numberp item2)) (< item1 item2))
	     ((numberp item1) (< item1 (car item2)))
	     ((numberp item2) (< (car item1) item2))
	     (t (< (car item1) (car item2)))))
      (setq item
	    (or
	     (let ((tmp1 item) (tmp2 (if selector item1 item2)))
	       (cond 
		((null tmp1) tmp2)
		((null tmp2) tmp1)
		((and (numberp tmp1) (numberp tmp2))
		 (cond 
		  ((eq tmp1 tmp2) tmp1)
		  ((eq (1+ tmp1) tmp2) (cons tmp1 tmp2))
		  ((eq (1+ tmp2) tmp1) (cons tmp2 tmp1))
		  (t nil)))
		((numberp tmp1)
		 (cond 
		  ((and (>= tmp1 (car tmp2)) (<= tmp1 (cdr tmp2))) tmp2)
		  ((eq (1+ tmp1) (car tmp2)) (cons tmp1 (cdr tmp2)))
		  ((eq (1- tmp1) (cdr tmp2)) (cons (car tmp2) tmp1))
		  (t nil)))
		((numberp tmp2)
		 (cond 
		  ((and (>= tmp2 (car tmp1)) (<= tmp2 (cdr tmp1))) tmp1)
		  ((eq (1+ tmp2) (car tmp1)) (cons tmp2 (cdr tmp1)))
		  ((eq (1- tmp2) (cdr tmp1)) (cons (car tmp1) tmp2))
		  (t nil)))
		((< (1+ (cdr tmp1)) (car tmp2)) nil)
		((< (1+ (cdr tmp2)) (car tmp1)) nil)
		(t (cons (min (car tmp1) (car tmp2)) 
			 (max (cdr tmp1) (cdr tmp2))))))
	     (progn
	       (if item (push item range))
	       (if selector item1 item2))))
      (if selector
	  (setq item1 (pop range1))
	(setq item2 (pop range2))))
    (if item (push item range))
    (reverse range)))

(provide 'gnus-range)

;;; gnus-range.el ends here