lisp/gnus/gnus-range.el

   1 ;;; gnus-range.el --- range and sequence functions for Gnus
   2
   3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   4
   5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   6 ;; Keywords: news
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  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 the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;;; Code:
  28
  29 (eval-when-compile (require 'cl))
  30
  31 ;;; List and range functions
  32
  33 (defun gnus-last-element (list)
  34   "Return last element of LIST."
  35   (while (cdr list)
  36     (setq list (cdr list)))
  37   (car list))
  38
  39 (defun gnus-copy-sequence (list)
  40   "Do a complete, total copy of a list."
  41   (let (out)
  42     (while (consp list)
  43       (if (consp (car list))
  44           (push (gnus-copy-sequence (pop list)) out)
  45         (push (pop list) out)))
  46     (if list
  47         (nconc (nreverse out) list)
  48       (nreverse out))))
  49
  50 (defun gnus-set-difference (list1 list2)
  51   "Return a list of elements of LIST1 that do not appear in LIST2."
  52   (let ((list1 (copy-sequence list1)))
  53     (while list2
  54       (setq list1 (delq (car list2) list1))
  55       (setq list2 (cdr list2)))
  56     list1))
  57
  58 (defun gnus-sorted-complement (list1 list2)
  59   "Return a list of elements that are in LIST1 or LIST2 but not both.
  60 Both lists have to be sorted over <."
  61   (let (out)
  62     (if (or (null list1) (null list2))
  63         (or list1 list2)
  64       (while (and list1 list2)
  65         (cond ((= (car list1) (car list2))
  66                (setq list1 (cdr list1)
  67                      list2 (cdr list2)))
  68               ((< (car list1) (car list2))
  69                (setq out (cons (car list1) out))
  70                (setq list1 (cdr list1)))
  71               (t
  72                (setq out (cons (car list2) out))
  73                (setq list2 (cdr list2)))))
  74       (nconc (nreverse out) (or list1 list2)))))
  75
  76 (defun gnus-intersection (list1 list2)
  77   (let ((result nil))
  78     (while list2
  79       (when (memq (car list2) list1)
  80         (setq result (cons (car list2) result)))
  81       (setq list2 (cdr list2)))
  82     result))
  83
  84 (defun gnus-sorted-intersection (list1 list2)
  85   ;; LIST1 and LIST2 have to be sorted over <.
  86   (let (out)
  87     (while (and list1 list2)
  88       (cond ((= (car list1) (car list2))
  89              (setq out (cons (car list1) out)
  90                    list1 (cdr list1)
  91                    list2 (cdr list2)))
  92             ((< (car list1) (car list2))
  93              (setq list1 (cdr list1)))
  94             (t
  95              (setq list2 (cdr list2)))))
  96     (nreverse out)))
  97
  98 (defun gnus-set-sorted-intersection (list1 list2)
  99   ;; LIST1 and LIST2 have to be sorted over <.
 100   ;; This function modifies LIST1.
 101   (let* ((top (cons nil list1))
 102          (prev top))
 103     (while (and list1 list2)
 104       (cond ((= (car list1) (car list2))
 105              (setq prev list1
 106                    list1 (cdr list1)
 107                    list2 (cdr list2)))
 108             ((< (car list1) (car list2))
 109              (setcdr prev (cdr list1))
 110              (setq list1 (cdr list1)))
 111             (t
 112              (setq list2 (cdr list2)))))
 113     (setcdr prev nil)
 114     (cdr top)))
 115
 116 (defun gnus-compress-sequence (numbers &optional always-list)
 117   "Convert list of numbers to a list of ranges or a single range.
 118 If ALWAYS-LIST is non-nil, this function will always release a list of
 119 ranges."
 120   (let* ((first (car numbers))
 121          (last (car numbers))
 122          result)
 123     (if (null numbers)
 124         nil
 125       (if (not (listp (cdr numbers)))
 126           numbers
 127         (while numbers
 128           (cond ((= last (car numbers)) nil) ;Omit duplicated number
 129                 ((= (1+ last) (car numbers)) ;Still in sequence
 130                  (setq last (car numbers)))
 131                 (t                      ;End of one sequence
 132                  (setq result
 133                        (cons (if (= first last) first
 134                                (cons first last))
 135                              result))
 136                  (setq first (car numbers))
 137                  (setq last  (car numbers))))
 138           (setq numbers (cdr numbers)))
 139         (if (and (not always-list) (null result))
 140             (if (= first last) (list first) (cons first last))
 141           (nreverse (cons (if (= first last) first (cons first last))
 142                           result)))))))
 143
 144 (defalias 'gnus-uncompress-sequence 'gnus-uncompress-range)
 145 (defun gnus-uncompress-range (ranges)
 146   "Expand a list of ranges into a list of numbers.
 147 RANGES is either a single range on the form `(num . num)' or a list of
 148 these ranges."
 149   (let (first last result)
 150     (cond
 151      ((null ranges)
 152       nil)
 153      ((not (listp (cdr ranges)))
 154       (setq first (car ranges))
 155       (setq last (cdr ranges))
 156       (while (<= first last)
 157         (setq result (cons first result))
 158         (setq first (1+ first)))
 159       (nreverse result))
 160      (t
 161       (while ranges
 162         (if (atom (car ranges))
 163             (when (numberp (car ranges))
 164               (setq result (cons (car ranges) result)))
 165           (setq first (caar ranges))
 166           (setq last  (cdar ranges))
 167           (while (<= first last)
 168             (setq result (cons first result))
 169             (setq first (1+ first))))
 170         (setq ranges (cdr ranges)))
 171       (nreverse result)))))
 172
 173 (defun gnus-add-to-range (ranges list)
 174   "Return a list of ranges that has all articles from both RANGES and LIST.
 175 Note: LIST has to be sorted over `<'."
 176   (if (not ranges)
 177       (gnus-compress-sequence list t)
 178     (setq list (copy-sequence list))
 179     (unless (listp (cdr ranges))
 180       (setq ranges (list ranges)))
 181     (let ((out ranges)
 182           ilist lowest highest temp)
 183       (while (and ranges list)
 184         (setq ilist list)
 185         (setq lowest (or (and (atom (car ranges)) (car ranges))
 186                          (caar ranges)))
 187         (while (and list (cdr list) (< (cadr list) lowest))
 188           (setq list (cdr list)))
 189         (when (< (car ilist) lowest)
 190           (setq temp list)
 191           (setq list (cdr list))
 192           (setcdr temp nil)
 193           (setq out (nconc (gnus-compress-sequence ilist t) out)))
 194         (setq highest (or (and (atom (car ranges)) (car ranges))
 195                           (cdar ranges)))
 196         (while (and list (<= (car list) highest))
 197           (setq list (cdr list)))
 198         (setq ranges (cdr ranges)))
 199       (when list
 200         (setq out (nconc (gnus-compress-sequence list t) out)))
 201       (setq out (sort out (lambda (r1 r2)
 202                             (< (or (and (atom r1) r1) (car r1))
 203                                (or (and (atom r2) r2) (car r2))))))
 204       (setq ranges out)
 205       (while ranges
 206         (if (atom (car ranges))
 207             (when (cdr ranges)
 208               (if (atom (cadr ranges))
 209                   (when (= (1+ (car ranges)) (cadr ranges))
 210                     (setcar ranges (cons (car ranges)
 211                                          (cadr ranges)))
 212                     (setcdr ranges (cddr ranges)))
 213                 (when (= (1+ (car ranges)) (caadr ranges))
 214                   (setcar (cadr ranges) (car ranges))
 215                   (setcar ranges (cadr ranges))
 216                   (setcdr ranges (cddr ranges)))))
 217           (when (cdr ranges)
 218             (if (atom (cadr ranges))
 219                 (when (= (1+ (cdar ranges)) (cadr ranges))
 220                   (setcdr (car ranges) (cadr ranges))
 221                   (setcdr ranges (cddr ranges)))
 222               (when (= (1+ (cdar ranges)) (caadr ranges))
 223                 (setcdr (car ranges) (cdadr ranges))
 224                 (setcdr ranges (cddr ranges))))))
 225         (setq ranges (cdr ranges)))
 226       out)))
 227
 228 (defun gnus-remove-from-range (range1 range2)
 229   "Return a range that has all articles from RANGE2 removed from RANGE1.
 230 The returned range is always a list.  RANGE2 can also be a unsorted
 231 list of articles.  RANGE1 is modified by side effects, RANGE2 is not
 232 modified."
 233   (if (or (null range1) (null range2))
 234       range1
 235     (let (out r1 r2 r1_min r1_max r2_min r2_max
 236               (range2 (gnus-copy-sequence range2)))
 237       (setq range1 (if (listp (cdr range1)) range1 (list range1))
 238             range2 (sort (if (listp (cdr range2)) range2 (list range2))
 239                          (lambda (e1 e2)
 240                            (< (if (consp e1) (car e1) e1)
 241                               (if (consp e2) (car e2) e2))))
 242             r1 (car range1)
 243             r2 (car range2)
 244             r1_min (if (consp r1) (car r1) r1)
 245             r1_max (if (consp r1) (cdr r1) r1)
 246             r2_min (if (consp r2) (car r2) r2)
 247             r2_max (if (consp r2) (cdr r2) r2))
 248       (while (and range1 range2)
 249         (cond ((< r2_max r1_min)        ; r2 < r1
 250                (pop range2)
 251                (setq r2 (car range2)
 252                      r2_min (if (consp r2) (car r2) r2)
 253                      r2_max (if (consp r2) (cdr r2) r2)))
 254               ((and (<= r2_min r1_min) (<= r1_max r2_max)) ; r2 overlap r1
 255                (pop range1)
 256                (setq r1 (car range1)
 257                      r1_min (if (consp r1) (car r1) r1)
 258                      r1_max (if (consp r1) (cdr r1) r1)))
 259               ((and (<= r2_min r1_min) (<= r2_max r1_max)) ; r2 overlap min r1
 260                (pop range2)
 261                (setq r1_min (1+ r2_max)
 262                      r2 (car range2)
 263                      r2_min (if (consp r2) (car r2) r2)
 264                      r2_max (if (consp r2) (cdr r2) r2)))
 265               ((and (<= r1_min r2_min) (<= r2_max r1_max)) ; r2 contained in r1
 266                (if (eq r1_min (1- r2_min))
 267                    (push r1_min out)
 268                  (push (cons r1_min (1- r2_min)) out))
 269                (pop range2)
 270                (if (< r2_max r1_max)    ; finished with r1?
 271                    (setq r1_min (1+ r2_max))
 272                  (pop range1)
 273                  (setq r1 (car range1)
 274                        r1_min (if (consp r1) (car r1) r1)
 275                        r1_max (if (consp r1) (cdr r1) r1)))
 276                (setq r2 (car range2)
 277                      r2_min (if (consp r2) (car r2) r2)
 278                      r2_max (if (consp r2) (cdr r2) r2)))
 279               ((and (<= r2_min r1_max) (<= r1_max r2_max)) ; r2 overlap max r1
 280                (if (eq r1_min (1- r2_min))
 281                    (push r1_min out)
 282                  (push (cons r1_min (1- r2_min)) out))
 283                (pop range1)
 284                (setq r1 (car range1)
 285                      r1_min (if (consp r1) (car r1) r1)
 286                      r1_max (if (consp r1) (cdr r1) r1)))
 287               ((< r1_max r2_min)        ; r2 > r1
 288                (pop range1)
 289                (if (eq r1_min r1_max)
 290                    (push r1_min out)
 291                  (push (cons r1_min r1_max) out))
 292                (setq r1 (car range1)
 293                      r1_min (if (consp r1) (car r1) r1)
 294                      r1_max (if (consp r1) (cdr r1) r1)))))
 295       (when r1
 296         (if (eq r1_min r1_max)
 297             (push r1_min out)
 298           (push (cons r1_min r1_max) out))
 299         (pop range1))
 300       (while range1
 301         (push (pop range1) out))
 302       (nreverse out))))
 303
 304 (defun gnus-member-of-range (number ranges)
 305   (if (not (listp (cdr ranges)))
 306       (and (>= number (car ranges))
 307            (<= number (cdr ranges)))
 308     (let ((not-stop t))
 309       (while (and ranges
 310                   (if (numberp (car ranges))
 311                       (>= number (car ranges))
 312                     (>= number (caar ranges)))
 313                   not-stop)
 314         (when (if (numberp (car ranges))
 315                   (= number (car ranges))
 316                 (and (>= number (caar ranges))
 317                      (<= number (cdar ranges))))
 318           (setq not-stop nil))
 319         (setq ranges (cdr ranges)))
 320       (not not-stop))))
 321
 322 (defun gnus-range-length (range)
 323   "Return the length RANGE would have if uncompressed."
 324   (length (gnus-uncompress-range range)))
 325
 326 (defun gnus-sublist-p (list sublist)
 327   "Test whether all elements in SUBLIST are members of LIST."
 328   (let ((sublistp t))
 329     (while sublist
 330       (unless (memq (pop sublist) list)
 331         (setq sublistp nil
 332               sublist nil)))
 333     sublistp))
 334
 335 (defun gnus-range-add (range1 range2)
 336   "Add RANGE2 to RANGE1 (nondestructively)."
 337   (unless (listp (cdr range1))
 338     (setq range1 (list range1)))
 339   (unless (listp (cdr range2))
 340     (setq range2 (list range2)))
 341   (let ((item1 (pop range1))
 342         (item2 (pop range2))
 343         range item selector)
 344     (while (or item1 item2)
 345       (setq selector
 346             (cond
 347              ((null item1) nil)
 348              ((null item2) t)
 349              ((and (numberp item1) (numberp item2)) (< item1 item2))
 350              ((numberp item1) (< item1 (car item2)))
 351              ((numberp item2) (< (car item1) item2))
 352              (t (< (car item1) (car item2)))))
 353       (setq item
 354             (or
 355              (let ((tmp1 item) (tmp2 (if selector item1 item2)))
 356                (cond
 357                 ((null tmp1) tmp2)
 358                 ((null tmp2) tmp1)
 359                 ((and (numberp tmp1) (numberp tmp2))
 360                  (cond
 361                   ((eq tmp1 tmp2) tmp1)
 362                   ((eq (1+ tmp1) tmp2) (cons tmp1 tmp2))
 363                   ((eq (1+ tmp2) tmp1) (cons tmp2 tmp1))
 364                   (t nil)))
 365                 ((numberp tmp1)
 366                  (cond
 367                   ((and (>= tmp1 (car tmp2)) (<= tmp1 (cdr tmp2))) tmp2)
 368                   ((eq (1+ tmp1) (car tmp2)) (cons tmp1 (cdr tmp2)))
 369                   ((eq (1- tmp1) (cdr tmp2)) (cons (car tmp2) tmp1))
 370                   (t nil)))
 371                 ((numberp tmp2)
 372                  (cond
 373                   ((and (>= tmp2 (car tmp1)) (<= tmp2 (cdr tmp1))) tmp1)
 374                   ((eq (1+ tmp2) (car tmp1)) (cons tmp2 (cdr tmp1)))
 375                   ((eq (1- tmp2) (cdr tmp1)) (cons (car tmp1) tmp2))
 376                   (t nil)))
 377                 ((< (1+ (cdr tmp1)) (car tmp2)) nil)
 378                 ((< (1+ (cdr tmp2)) (car tmp1)) nil)
 379                 (t (cons (min (car tmp1) (car tmp2))
 380                          (max (cdr tmp1) (cdr tmp2))))))
 381              (progn
 382                (if item (push item range))
 383                (if selector item1 item2))))
 384       (if selector
 385           (setq item1 (pop range1))
 386         (setq item2 (pop range2))))
 387     (if item (push item range))
 388     (reverse range)))
 389
 390 (provide 'gnus-range)
 391
 392 ;;; gnus-range.el ends here