code.delx.au - gnu-emacs/blob - lisp/mh-e/mh-seq.el

   1 ;;; mh-seq.el --- MH-E sequences support
   2
   3 ;; Copyright (C) 1993, 1995,
   4 ;;  2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   5
   6 ;; Author: Bill Wohler <wohler@newt.com>
   7 ;; Maintainer: Bill Wohler <wohler@newt.com>
   8 ;; Keywords: mail
   9 ;; See: mh-e.el
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software; you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation; either version 2, or (at your option)
  16 ;; any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  25 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26 ;; Boston, MA 02110-1301, USA.
  27
  28 ;;; Commentary:
  29 ;;
  30 ;;   This tries to implement the algorithm described at:
  31 ;;     http://www.jwz.org/doc/threading.html
  32 ;;   It is also a start to implementing the IMAP Threading extension RFC. The
  33 ;;   implementation lacks the reference and subject canonicalization of the
  34 ;;   RFC.
  35 ;;
  36 ;;   In the presentation buffer, children messages are shown indented with
  37 ;;   either [ ] or < > around them. Square brackets ([ ]) denote that the
  38 ;;   algorithm can point out some headers which when taken together implies
  39 ;;   that the unindented message is an ancestor of the indented message. If
  40 ;;   no such proof exists then angles (< >) are used.
  41 ;;
  42 ;;   Some issues and problems are as follows:
  43 ;;
  44 ;;    (1) Scan truncates the fields at length 512. So longer references:
  45 ;;        headers get mutilated. The same kind of MH format string works when
  46 ;;        composing messages. Is there a way to avoid this? My scan command
  47 ;;        is as follows:
  48 ;;          scan +folder -width 10000 \
  49 ;;               -format "%(msg)\n%{message-id}\n%{references}\n%{subject}\n"
  50 ;;        I would really appreciate it if someone would help me with this.
  51 ;;
  52 ;;    (2) Implement heuristics to recognize message identifiers in
  53 ;;        In-Reply-To: header. Right now it just assumes that the last text
  54 ;;        between angles (< and >) is the message identifier. There is the
  55 ;;        chance that this will incorrectly use an email address like a
  56 ;;        message identifier.
  57 ;;
  58 ;;    (3) Error checking of found message identifiers should be done.
  59 ;;
  60 ;;    (4) Since this breaks the assumption that message indices increase as
  61 ;;        one goes down the buffer, the binary search based mh-goto-msg
  62 ;;        doesn't work. I have a simpler replacement which may be less
  63 ;;        efficient.
  64 ;;
  65 ;;    (5) Better canonicalizing for message identifier and subject strings.
  66 ;;
  67
  68 ;; Internal support for MH-E package.
  69
  70 ;;; Change Log:
  71
  72 ;;; Code:
  73
  74 (eval-when-compile (require 'mh-acros))
  75 (mh-require-cl)
  76 (require 'mh-e)
  77
  78 ;; Shush the byte-compiler
  79 (defvar tool-bar-mode)
  80
  81 \f
  82
  83 ;;; Data structures (used in message threading)...
  84
  85 (mh-defstruct (mh-thread-message (:conc-name mh-message-)
  86                                  (:constructor mh-thread-make-message))
  87   (id nil)
  88   (references ())
  89   (subject "")
  90   (subject-re-p nil))
  91
  92 (mh-defstruct (mh-thread-container (:conc-name mh-container-)
  93                                    (:constructor mh-thread-make-container))
  94   message parent children
  95   (real-child-p t))
  96
  97 \f
  98
  99 ;;; Internal variables:
 100
 101 (defvar mh-last-seq-used nil
 102   "Name of seq to which a msg was last added.")
 103
 104 (defvar mh-non-seq-mode-line-annotation nil
 105   "Saved value of `mh-mode-line-annotation' when narrowed to a seq.")
 106
 107 \f
 108
 109 ;;; Maps and hashes...
 110
 111 (defvar mh-thread-id-hash nil
 112   "Hashtable used to canonicalize message identifiers.")
 113 (defvar mh-thread-subject-hash nil
 114   "Hashtable used to canonicalize subject strings.")
 115 (defvar mh-thread-id-table nil
 116   "Thread ID table maps from message identifiers to message containers.")
 117 (defvar mh-thread-id-index-map nil
 118   "Table to look up message index number from message identifier.")
 119 (defvar mh-thread-index-id-map nil
 120   "Table to look up message identifier from message index.")
 121 (defvar mh-thread-scan-line-map nil
 122   "Map of message index to various parts of the scan line.")
 123 (defvar mh-thread-scan-line-map-stack nil
 124   "Old map of message index to various parts of the scan line.
 125 This is the original map that is stored when the folder is
 126 narrowed.")
 127 (defvar mh-thread-subject-container-hash nil
 128   "Hashtable used to group messages by subject.")
 129 (defvar mh-thread-duplicates nil
 130   "Hashtable used to associate messages with the same message identifier.")
 131 (defvar mh-thread-history ()
 132   "Variable to remember the transformations to the thread tree.
 133 When new messages are added, these transformations are rewound,
 134 then the links are added from the newly seen messages. Finally
 135 the transformations are redone to get the new thread tree. This
 136 makes incremental threading easier.")
 137 (defvar mh-thread-body-width nil
 138   "Width of scan substring that contains subject and body of message.")
 139
 140 (make-variable-buffer-local 'mh-thread-id-hash)
 141 (make-variable-buffer-local 'mh-thread-subject-hash)
 142 (make-variable-buffer-local 'mh-thread-id-table)
 143 (make-variable-buffer-local 'mh-thread-id-index-map)
 144 (make-variable-buffer-local 'mh-thread-index-id-map)
 145 (make-variable-buffer-local 'mh-thread-scan-line-map)
 146 (make-variable-buffer-local 'mh-thread-scan-line-map-stack)
 147 (make-variable-buffer-local 'mh-thread-subject-container-hash)
 148 (make-variable-buffer-local 'mh-thread-duplicates)
 149 (make-variable-buffer-local 'mh-thread-history)
 150
 151 ;;;###mh-autoload
 152 (defun mh-delete-seq (sequence)
 153   "Delete SEQUENCE.
 154
 155 You are prompted for the sequence to delete. Note that this
 156 deletes only the sequence, not the messages in the sequence. If
 157 you want to delete the messages, use \"\\[universal-argument]
 158 \\[mh-delete-msg]\"."
 159   (interactive (list (mh-read-seq-default "Delete" t)))
 160   (let ((msg-list (mh-seq-to-msgs sequence))
 161         (internal-flag (mh-internal-seq sequence))
 162         (folders-changed (list mh-current-folder)))
 163     (mh-iterate-on-range msg sequence
 164       (mh-remove-sequence-notation msg internal-flag))
 165     (mh-undefine-sequence sequence '("all"))
 166     (mh-delete-seq-locally sequence)
 167     (when mh-index-data
 168       (setq folders-changed
 169             (append folders-changed
 170                     (mh-index-delete-from-sequence sequence msg-list))))
 171     (when (and (eq sequence mh-unseen-seq) (mh-speed-flists-active-p))
 172       (apply #'mh-speed-flists t folders-changed))))
 173
 174 ;; Avoid compiler warnings
 175 (defvar view-exit-action)
 176
 177 ;;;###mh-autoload
 178 (defun mh-list-sequences ()
 179   "List all sequences in folder.
 180 The list appears in a buffer named \"*MH-E Sequences*\"."
 181   (interactive)
 182   (let ((folder mh-current-folder)
 183         (temp-buffer mh-sequences-buffer)
 184         (seq-list mh-seq-list)
 185         (max-len 0))
 186     (with-output-to-temp-buffer temp-buffer
 187       (save-excursion
 188         (set-buffer temp-buffer)
 189         (erase-buffer)
 190         (message "Listing sequences ...")
 191         (insert "Sequences in folder " folder ":\n")
 192         (let ((seq-list seq-list))
 193           (while seq-list
 194             (setq max-len
 195                   (max (length (symbol-name (mh-seq-name (pop seq-list))))
 196                        max-len)))
 197           (setq max-len (+ 2 max-len)))
 198         (while seq-list
 199           (let ((name (mh-seq-name (car seq-list)))
 200                 (sorted-seq-msgs
 201                  (mh-coalesce-msg-list
 202                   (sort (copy-sequence (mh-seq-msgs (car seq-list))) '<)))
 203                 name-spec)
 204             (insert (setq name-spec (format (format "%%%ss:" max-len) name)))
 205             (while sorted-seq-msgs
 206               (let ((next-element (format " %s" (pop sorted-seq-msgs))))
 207                 (when (>= (+ (current-column) (length next-element))
 208                           (window-width))
 209                   (insert "\n")
 210                   (insert (format (format "%%%ss" (length name-spec)) "")))
 211                 (insert next-element)))
 212             (insert "\n"))
 213           (setq seq-list (cdr seq-list)))
 214         (goto-char (point-min))
 215         (view-mode-enter)
 216         (setq view-exit-action 'kill-buffer)
 217         (message "Listing sequences...done")))))
 218
 219 ;;;###mh-autoload
 220 (defun mh-msg-is-in-seq (message)
 221   "Display the sequences in which the current message appears.
 222 Use a prefix argument to display the sequences in which another
 223 MESSAGE appears."
 224   (interactive "P")
 225   (if (not message)
 226       (setq message (mh-get-msg-num t)))
 227   (let* ((dest-folder (loop for seq in mh-refile-list
 228                             when (member message (cdr seq)) return (car seq)
 229                             finally return nil))
 230          (deleted-flag (unless dest-folder (member message mh-delete-list))))
 231     (message "Message %d%s is in sequences: %s"
 232              message
 233              (cond (dest-folder (format " (to be refiled to %s)" dest-folder))
 234                    (deleted-flag (format " (to be deleted)"))
 235                    (t ""))
 236              (mapconcat 'concat
 237                         (mh-list-to-string (mh-seq-containing-msg message t))
 238                         " "))))
 239
 240 ;; Avoid compiler warning
 241 (defvar tool-bar-map)
 242
 243 (make-variable-buffer-local 'mh-non-seq-mode-line-annotation)
 244
 245 ;;;###mh-autoload
 246 (defun mh-narrow-to-seq (sequence)
 247   "Restrict display to messages in SEQUENCE.
 248
 249 You are prompted for the name of the sequence. What this command
 250 does is show only those messages that are in the selected
 251 sequence in the MH-Folder buffer. In addition, it limits further
 252 MH-E searches to just those messages.
 253
 254 When you want to widen the view to all your messages again, use
 255 \\[mh-widen]."
 256   (interactive (list (mh-read-seq "Narrow to" t)))
 257   (with-mh-folder-updating (t)
 258     (cond ((mh-seq-to-msgs sequence)
 259            (mh-remove-all-notation)
 260            (let ((eob (point-max))
 261                  (msg-at-cursor (mh-get-msg-num nil)))
 262              (push mh-thread-scan-line-map mh-thread-scan-line-map-stack)
 263              (setq mh-thread-scan-line-map (make-hash-table :test #'eql))
 264              (mh-copy-seq-to-eob sequence)
 265              (push (buffer-substring-no-properties (point-min) eob)
 266                    mh-folder-view-stack)
 267              (delete-region (point-min) eob)
 268              (mh-notate-deleted-and-refiled)
 269              (mh-notate-cur)
 270              (when msg-at-cursor (mh-goto-msg msg-at-cursor t t))
 271              (setq mh-non-seq-mode-line-annotation mh-mode-line-annotation)
 272              (setq mh-mode-line-annotation (symbol-name sequence))
 273              (mh-make-folder-mode-line)
 274              (mh-recenter nil)
 275              (when (and (boundp 'tool-bar-mode) tool-bar-mode)
 276                (set (make-local-variable 'tool-bar-map)
 277                     mh-folder-seq-tool-bar-map)
 278                (when (buffer-live-p (get-buffer mh-show-buffer))
 279                  (save-excursion
 280                    (set-buffer (get-buffer mh-show-buffer))
 281                    (set (make-local-variable 'tool-bar-map)
 282                         mh-show-seq-tool-bar-map))))
 283              (push 'widen mh-view-ops)))
 284           (t
 285            (error "No messages in sequence \"%s\"" (symbol-name sequence))))))
 286
 287 ;;;###mh-autoload
 288 (defun mh-put-msg-in-seq (range sequence)
 289   "Add RANGE to SEQUENCE\\<mh-folder-mode-map>.
 290
 291 To place a message in a sequence, use this command to do it
 292 manually, or use the MH command \"pick\" or the MH-E version of
 293 \"pick\", \\[mh-search-folder], which create a sequence
 294 automatically.
 295
 296 Give this command a RANGE and you can add all the messages in a
 297 sequence to another sequence (for example,
 298 \"\\[universal-argument] \\[mh-put-msg-in-seq] SourceSequence RET
 299 DestSequence RET\"). Check the documentation of
 300 `mh-interactive-range' to see how RANGE is read in interactive
 301 use."
 302   (interactive (list (mh-interactive-range "Add messages from")
 303                      (mh-read-seq-default "Add to" nil)))
 304   (unless (mh-valid-seq-p sequence)
 305     (error "Can't put message in invalid sequence \"%s\"" sequence))
 306   (let* ((internal-seq-flag (mh-internal-seq sequence))
 307          (original-msgs (mh-seq-msgs (mh-find-seq sequence)))
 308          (folders (list mh-current-folder))
 309          (msg-list (mh-range-to-msg-list range)))
 310     (mh-add-msgs-to-seq msg-list sequence nil t)
 311     (mh-iterate-on-range m range
 312       (unless (memq m original-msgs)
 313         (mh-add-sequence-notation m internal-seq-flag)))
 314     (if (not internal-seq-flag)
 315         (setq mh-last-seq-used sequence))
 316     (when mh-index-data
 317       (setq folders
 318             (append folders (mh-index-add-to-sequence sequence msg-list))))
 319     (when (and (eq sequence mh-unseen-seq) (mh-speed-flists-active-p))
 320       (apply #'mh-speed-flists t folders))))
 321
 322 (defun mh-valid-view-change-operation-p (op)
 323   "Check if the view change operation can be performed.
 324 OP is one of 'widen and 'unthread."
 325   (cond ((eq (car mh-view-ops) op)
 326          (pop mh-view-ops))
 327         (t nil)))
 328
 329 ;;;###mh-autoload
 330 (defun mh-widen (&optional all-flag)
 331   "Remove last restriction.
 332 If optional prefix argument ALL-FLAG is non-nil, remove all
 333 limits."
 334   (interactive "P")
 335   (let ((msg (mh-get-msg-num nil)))
 336     (when mh-folder-view-stack
 337       (cond (all-flag
 338              (while (cdr mh-view-ops)
 339                (setq mh-view-ops (cdr mh-view-ops)))
 340              (when (eq (car mh-view-ops) 'widen)
 341                (setq mh-view-ops (cdr mh-view-ops))))
 342             ((mh-valid-view-change-operation-p 'widen) nil)
 343             ((memq 'widen mh-view-ops)
 344              (while (not (eq (car mh-view-ops) 'widen))
 345                (setq mh-view-ops (cdr mh-view-ops)))
 346              (setq mh-view-ops (cdr mh-view-ops)))
 347             (t (error "Widening is not applicable")))
 348       ;; If ALL-FLAG is non-nil then rewind stacks
 349       (when all-flag
 350         (while (cdr mh-thread-scan-line-map-stack)
 351           (setq mh-thread-scan-line-map-stack
 352                 (cdr mh-thread-scan-line-map-stack)))
 353         (while (cdr mh-folder-view-stack)
 354           (setq mh-folder-view-stack (cdr mh-folder-view-stack))))
 355       (setq mh-thread-scan-line-map (pop mh-thread-scan-line-map-stack))
 356       (with-mh-folder-updating (t)
 357         (delete-region (point-min) (point-max))
 358         (insert (pop mh-folder-view-stack))
 359         (mh-remove-all-notation)
 360         (setq mh-mode-line-annotation mh-non-seq-mode-line-annotation)
 361         (mh-make-folder-mode-line))
 362       (if msg
 363           (mh-goto-msg msg t t))
 364       (mh-notate-deleted-and-refiled)
 365       (mh-notate-user-sequences)
 366       (mh-notate-cur)
 367       (mh-recenter nil)))
 368   (when (and (null mh-folder-view-stack) (boundp 'tool-bar-mode) tool-bar-mode)
 369     (set (make-local-variable 'tool-bar-map) mh-folder-tool-bar-map)
 370     (when (buffer-live-p (get-buffer mh-show-buffer))
 371       (save-excursion
 372         (set-buffer (get-buffer mh-show-buffer))
 373         (set (make-local-variable 'tool-bar-map) mh-show-tool-bar-map)))))
 374
 375 ;; FIXME?  We may want to clear all notations and add one for current-message
 376 ;;         and process user sequences.
 377 ;;;###mh-autoload
 378 (defun mh-notate-deleted-and-refiled ()
 379   "Notate messages marked for deletion or refiling.
 380 Messages to be deleted are given by `mh-delete-list' while
 381 messages to be refiled are present in `mh-refile-list'."
 382   (let ((refiled-hash (make-hash-table))
 383         (deleted-hash (make-hash-table)))
 384     (dolist (msg mh-delete-list)
 385       (setf (gethash msg deleted-hash) t))
 386     (dolist (dest-msg-list mh-refile-list)
 387       (dolist (msg (cdr dest-msg-list))
 388         (setf (gethash msg refiled-hash) t)))
 389     (mh-iterate-on-messages-in-region msg (point-min) (point-max)
 390       (cond ((gethash msg refiled-hash)
 391              (mh-notate nil mh-note-refiled mh-cmd-note))
 392             ((gethash msg deleted-hash)
 393              (mh-notate nil mh-note-deleted mh-cmd-note))))))
 394
 395 \f
 396
 397 ;;; Commands to manipulate sequences.
 398
 399 ;; Sequences are stored in an alist of the form:
 400 ;;     ((seq-name msgs ...) (seq-name msgs ...) ...)
 401
 402 (defvar mh-sequence-history ())
 403
 404 ;;;###mh-autoload
 405 (defun mh-read-seq-default (prompt not-empty)
 406   "Read and return sequence name with default narrowed or previous sequence.
 407 PROMPT is the prompt to use when reading. If NOT-EMPTY is non-nil
 408 then a non-empty sequence is read."
 409   (mh-read-seq prompt not-empty
 410                (or mh-last-seq-used
 411                    (car (mh-seq-containing-msg (mh-get-msg-num nil) nil)))))
 412
 413 (defun mh-read-seq (prompt not-empty &optional default)
 414   "Read and return a sequence name.
 415 Prompt with PROMPT, raise an error if the sequence is empty and
 416 the NOT-EMPTY flag is non-nil, and supply an optional DEFAULT
 417 sequence. A reply of '%' defaults to the first sequence
 418 containing the current message."
 419   (let* ((input (completing-read (format "%s %s %s" prompt "sequence:"
 420                                          (if default
 421                                              (format "[%s] " default)
 422                                            ""))
 423                                  (mh-seq-names mh-seq-list)
 424                                  nil nil nil 'mh-sequence-history))
 425          (seq (cond ((equal input "%")
 426                      (car (mh-seq-containing-msg (mh-get-msg-num t) nil)))
 427                     ((equal input "") default)
 428                     (t (intern input))))
 429          (msgs (mh-seq-to-msgs seq)))
 430     (if (and (null msgs) not-empty)
 431         (error "No messages in sequence \"%s\"" seq))
 432     seq))
 433
 434 \f
 435
 436 ;;; Functions to read ranges with completion...
 437
 438 (defvar mh-range-seq-names)
 439 (defvar mh-range-history ())
 440 (defvar mh-range-completion-map (copy-keymap minibuffer-local-completion-map))
 441 (define-key mh-range-completion-map " " 'self-insert-command)
 442
 443 (defun mh-range-completion-function (string predicate flag)
 444   "Programmable completion of message ranges.
 445 STRING is the user input that is to be completed. PREDICATE if non-nil is a
 446 function used to filter the possible choices and FLAG determines whether the
 447 completion is over."
 448   (let* ((candidates mh-range-seq-names)
 449          (last-char (and (not (equal string ""))
 450                          (aref string (1- (length string)))))
 451          (last-word (cond ((null last-char) "")
 452                           ((memq last-char '(?  ?- ?:)) "")
 453                           (t (car (last (split-string string "[ -:]+"))))))
 454          (prefix (substring string 0 (- (length string) (length last-word)))))
 455     (cond ((eq flag nil)
 456            (let ((res (try-completion last-word candidates predicate)))
 457              (cond ((null res) nil)
 458                    ((eq res t) t)
 459                    (t (concat prefix res)))))
 460           ((eq flag t)
 461            (all-completions last-word candidates predicate))
 462           ((eq flag 'lambda)
 463            (loop for x in candidates
 464                  when (equal x last-word) return t
 465                  finally return nil)))))
 466
 467 ;;;###mh-autoload
 468 (defun mh-read-range (prompt &optional folder default
 469                              expand-flag ask-flag number-as-range-flag)
 470   "Read a message range with PROMPT.
 471
 472 If FOLDER is non-nil then a range is read from that folder, otherwise
 473 use `mh-current-folder'.
 474
 475 If DEFAULT is a string then use that as default range to return. If
 476 DEFAULT is nil then ask user with default answer a range based on the
 477 sequences that seem relevant. Finally if DEFAULT is t, try to avoid
 478 prompting the user. Unseen messages, if present, are returned. If the
 479 folder has fewer than `mh-large-folder' messages then \"all\" messages
 480 are returned. Finally as a last resort prompt the user.
 481
 482 If EXPAND-FLAG is non-nil then a list of message numbers corresponding
 483 to the input is returned. If this list is empty then an error is
 484 raised. If EXPAND-FLAG is nil just return the input string. In this
 485 case we don't check if the range is empty.
 486
 487 If ASK-FLAG is non-nil, then the user is always queried for a range of
 488 messages. If ASK-FLAG is nil, then the function checks if the unseen
 489 sequence is non-empty. If that is the case, `mh-unseen-seq', or the
 490 list of messages in it depending on the value of EXPAND, is returned.
 491 Otherwise if the folder has fewer than `mh-large-folder' messages then
 492 the list of messages corresponding to \"all\" is returned. If neither
 493 of the above holds then as a last resort the user is queried for a
 494 range of messages.
 495
 496 If NUMBER-AS-RANGE-FLAG is non-nil, then if a number, N is read as
 497 input, it is interpreted as the range \"last:N\".
 498
 499 This function replaces the existing function `mh-read-msg-range'.
 500 Calls to:
 501
 502   (mh-read-msg-range folder flag)
 503
 504 should be replaced with:
 505
 506   (mh-read-range \"Suitable prompt\" folder t nil flag
 507                  mh-interpret-number-as-range-flag)"
 508   (setq default (or default mh-last-seq-used
 509                     (car (mh-seq-containing-msg (mh-get-msg-num nil) t)))
 510         prompt (format "%s range" prompt))
 511   (let* ((folder (or folder mh-current-folder))
 512          (default (cond ((or (eq default t) (stringp default)) default)
 513                         ((symbolp default) (symbol-name default))))
 514          (guess (eq default t))
 515          (counts (and guess (mh-folder-size folder)))
 516          (unseen (and counts (> (cadr counts) 0)))
 517          (large (and counts mh-large-folder (> (car counts) mh-large-folder)))
 518          (str (cond ((and guess large
 519                           (setq default (format "last:%s" mh-large-folder)
 520                                 prompt (format "%s (folder has %s messages)"
 521                                                prompt (car counts)))
 522                           nil))
 523                     ((and guess (not large) (setq default "all") nil))
 524                     ((eq default nil) "")
 525                     (t (format "[%s] " default))))
 526          (minibuffer-local-completion-map mh-range-completion-map)
 527          (seq-list (if (eq folder mh-current-folder)
 528                        mh-seq-list
 529                      (mh-read-folder-sequences folder nil)))
 530          (mh-range-seq-names
 531           (append '(("first") ("last") ("all") ("prev") ("next"))
 532                   (mh-seq-names seq-list)))
 533          (input (cond ((and (not ask-flag) unseen) (symbol-name mh-unseen-seq))
 534                       ((and (not ask-flag) (not large)) "all")
 535                       (t (completing-read (format "%s: %s" prompt str)
 536                                           'mh-range-completion-function nil nil
 537                                           nil 'mh-range-history default))))
 538          msg-list)
 539     (when (and number-as-range-flag
 540                (string-match "^[ \t]*\\([0-9]+\\)[ \t]*$" input))
 541       (setq input (concat "last:" (match-string 1 input))))
 542     (cond ((not expand-flag) input)
 543           ((assoc (intern input) seq-list)
 544            (cdr (assoc (intern input) seq-list)))
 545           ((setq msg-list (mh-translate-range folder input)) msg-list)
 546           (t (error "No messages in range \"%s\"" input)))))
 547
 548 ;;;###mh-autoload
 549 (defun mh-translate-range (folder expr)
 550   "In FOLDER, translate the string EXPR to a list of messages numbers."
 551   (save-excursion
 552     (let ((strings (delete "" (split-string expr "[ \t\n]")))
 553           (result ()))
 554       (ignore-errors
 555         (apply #'mh-exec-cmd-quiet nil "mhpath" folder strings)
 556         (set-buffer mh-temp-buffer)
 557         (goto-char (point-min))
 558         (while (re-search-forward "/\\([0-9]*\\)$" nil t)
 559           (push (car (read-from-string (match-string 1))) result))
 560         (nreverse result)))))
 561
 562 (defun mh-seq-names (seq-list)
 563   "Return an alist containing the names of the SEQ-LIST."
 564   (mapcar (lambda (entry) (list (symbol-name (mh-seq-name entry))))
 565           seq-list))
 566
 567 ;;;###mh-autoload
 568 (defun mh-rename-seq (sequence new-name)
 569   "Rename SEQUENCE to have NEW-NAME."
 570   (interactive (list (mh-read-seq "Old" t)
 571                      (intern (read-string "New sequence name: "))))
 572   (let ((old-seq (mh-find-seq sequence)))
 573     (or old-seq
 574         (error "Sequence %s does not exist" sequence))
 575     ;; create new sequence first, since it might raise an error.
 576     (mh-define-sequence new-name (mh-seq-msgs old-seq))
 577     (mh-undefine-sequence sequence (mh-seq-msgs old-seq))
 578     (rplaca old-seq new-name)))
 579
 580 ;;;###mh-autoload
 581 (defun mh-notate-cur ()
 582   "Mark the MH sequence cur.
 583 In addition to notating the current message with `mh-note-cur'
 584 the function uses `overlay-arrow-position' to put a marker in the
 585 fringe."
 586   (let ((cur (car (mh-seq-to-msgs 'cur))))
 587     (when (and cur (mh-goto-msg cur t t))
 588       (beginning-of-line)
 589       (when (looking-at mh-scan-good-msg-regexp)
 590         (mh-notate nil mh-note-cur mh-cmd-note))
 591       (setq mh-arrow-marker (set-marker mh-arrow-marker (point)))
 592       (setq overlay-arrow-position mh-arrow-marker))))
 593
 594 ;;;###mh-autoload
 595 (defun mh-add-to-sequence (seq msgs)
 596   "The sequence SEQ is augmented with the messages in MSGS."
 597   ;; Add to a SEQUENCE each message the list of MSGS.
 598   (if (and (mh-valid-seq-p seq) (not (mh-folder-name-p seq)))
 599       (if msgs
 600           (apply 'mh-exec-cmd "mark" mh-current-folder "-add"
 601                  "-sequence" (symbol-name seq)
 602                  (mh-coalesce-msg-list msgs)))))
 603
 604 (defvar mh-thread-last-ancestor)
 605
 606 (defun mh-copy-seq-to-eob (seq)
 607   "Copy SEQ to the end of the buffer."
 608   ;; It is quite involved to write something which will work at any place in
 609   ;; the buffer, so we will write something which works only at the end of
 610   ;; the buffer. If we ever need to insert sequences in the middle of the
 611   ;; buffer, this will need to be fixed.
 612   (save-excursion
 613     (let* ((msgs (mh-seq-to-msgs seq))
 614            (coalesced-msgs (mh-coalesce-msg-list msgs)))
 615       (goto-char (point-max))
 616       (save-restriction
 617         (narrow-to-region (point) (point))
 618         (mh-regenerate-headers coalesced-msgs t)
 619         (cond ((memq 'unthread mh-view-ops)
 620                ;; Populate restricted scan-line map
 621                (mh-remove-all-notation)
 622                (mh-iterate-on-range msg (cons (point-min) (point-max))
 623                  (setf (gethash msg mh-thread-scan-line-map)
 624                        (mh-thread-parse-scan-line)))
 625                ;; Remove scan lines and read results from pre-computed tree
 626                (delete-region (point-min) (point-max))
 627                (mh-thread-print-scan-lines
 628                 (mh-thread-generate mh-current-folder ()))
 629                (mh-notate-user-sequences))
 630               (mh-index-data
 631                (mh-index-insert-folder-headers)))))))
 632
 633 ;;;###mh-autoload
 634 (defmacro mh-iterate-on-messages-in-region (var begin end &rest body)
 635   "Iterate over region.
 636
 637 VAR is bound to the message on the current line as we loop
 638 starting from BEGIN till END. In each step BODY is executed.
 639
 640 If VAR is nil then the loop is executed without any binding."
 641   (unless (symbolp var)
 642     (error "Can not bind the non-symbol %s" var))
 643   (let ((binding-needed-flag var))
 644     `(save-excursion
 645        (goto-char ,begin)
 646        (beginning-of-line)
 647        (while (and (<= (point) ,end) (not (eobp)))
 648          (when (looking-at mh-scan-valid-regexp)
 649            (let ,(if binding-needed-flag `((,var (mh-get-msg-num t))) ())
 650              ,@body))
 651          (forward-line 1)))))
 652
 653 (put 'mh-iterate-on-messages-in-region 'lisp-indent-hook 'defun)
 654
 655 ;;;###mh-autoload
 656 (defmacro mh-iterate-on-range (var range &rest body)
 657   "Iterate an operation over a region or sequence.
 658
 659 VAR is bound to each message in turn in a loop over RANGE, which
 660 can be a message number, a list of message numbers, a sequence, a
 661 region in a cons cell, or a MH range (something like last:20) in
 662 a string. In each iteration, BODY is executed.
 663
 664 The parameter RANGE is usually created with
 665 `mh-interactive-range' in order to provide a uniform interface to
 666 MH-E functions."
 667   (unless (symbolp var)
 668     (error "Can not bind the non-symbol %s" var))
 669   (let ((binding-needed-flag var)
 670         (msgs (make-symbol "msgs"))
 671         (seq-hash-table (make-symbol "seq-hash-table")))
 672     `(cond ((numberp ,range)
 673             (when (mh-goto-msg ,range t t)
 674               (let ,(if binding-needed-flag `((,var ,range)) ())
 675                 ,@body)))
 676            ((and (consp ,range)
 677                  (numberp (car ,range)) (numberp (cdr ,range)))
 678             (mh-iterate-on-messages-in-region ,var
 679               (car ,range) (cdr ,range)
 680               ,@body))
 681            (t (let ((,msgs (cond ((and ,range (symbolp ,range))
 682                                   (mh-seq-to-msgs ,range))
 683                                  ((stringp ,range)
 684                                   (mh-translate-range mh-current-folder
 685                                                       ,range))
 686                                  (t ,range)))
 687                     (,seq-hash-table (make-hash-table)))
 688                 (dolist (msg ,msgs)
 689                   (setf (gethash msg ,seq-hash-table) t))
 690                 (mh-iterate-on-messages-in-region v (point-min) (point-max)
 691                   (when (gethash v ,seq-hash-table)
 692                     (let ,(if binding-needed-flag `((,var v)) ())
 693                       ,@body))))))))
 694
 695 (put 'mh-iterate-on-range 'lisp-indent-hook 'defun)
 696
 697 ;;;###mh-autoload
 698 (defun mh-range-to-msg-list (range)
 699   "Return a list of messages for RANGE.
 700
 701 Check the documentation of `mh-interactive-range' to see how
 702 RANGE is read in interactive use."
 703   (let (msg-list)
 704     (mh-iterate-on-range msg range
 705       (push msg msg-list))
 706     (nreverse msg-list)))
 707
 708 ;;;###mh-autoload
 709 (defun mh-interactive-range (range-prompt &optional default)
 710   "Return interactive specification for message, sequence, range or region.
 711 By convention, the name of this argument is RANGE.
 712
 713 If variable `transient-mark-mode' is non-nil and the mark is active,
 714 then this function returns a cons-cell of the region.
 715
 716 If optional prefix argument is provided, then prompt for message range
 717 with RANGE-PROMPT. A list of messages in that range is returned.
 718
 719 If a MH range is given, say something like last:20, then a list
 720 containing the messages in that range is returned.
 721
 722 If DEFAULT non-nil then it is returned.
 723
 724 Otherwise, the message number at point is returned.
 725
 726 This function is usually used with `mh-iterate-on-range' in order to
 727 provide a uniform interface to MH-E functions."
 728   (cond ((mh-mark-active-p t) (cons (region-beginning) (region-end)))
 729         (current-prefix-arg (mh-read-range range-prompt nil nil t t))
 730         (default default)
 731         (t (mh-get-msg-num t))))
 732
 733 \f
 734
 735 ;;; Commands to handle new 'subject sequence ("Poor man's threading" by psg)
 736
 737 ;; XXX: The function mh-subject-to-sequence-unthreaded uses the magic number
 738 ;;  41 for the max size of the subject part. Avoiding this would be desirable.
 739 (defun mh-subject-to-sequence (all)
 740   "Put all following messages with same subject in sequence 'subject.
 741 If arg ALL is t, move to beginning of folder buffer to collect all
 742 messages.
 743 If arg ALL is nil, collect only messages fron current one on forward.
 744
 745 Return number of messages put in the sequence:
 746
 747  nil -> there was no subject line.
 748
 749  0   -> there were no later messages with the same
 750         subject (sequence not made)
 751
 752  >1  -> the total number of messages including current one."
 753   (if (memq 'unthread mh-view-ops)
 754       (mh-subject-to-sequence-threaded all)
 755     (mh-subject-to-sequence-unthreaded all)))
 756
 757 (defun mh-subject-to-sequence-unthreaded (all)
 758   "Put all following messages with same subject in sequence 'subject.
 759
 760 This function only works with an unthreaded folder. If arg ALL is
 761 t, move to beginning of folder buffer to collect all messages. If
 762 arg ALL is nil, collect only messages fron current one on
 763 forward.
 764
 765 Return number of messages put in the sequence:
 766
 767  nil -> there was no subject line.
 768  0   -> there were no later messages with the same
 769         subject (sequence not made)
 770  >1  -> the total number of messages including current one."
 771   (if (not (eq major-mode 'mh-folder-mode))
 772       (error "Not in a folder buffer"))
 773   (save-excursion
 774     (beginning-of-line)
 775     (if (or (not (looking-at mh-scan-subject-regexp))
 776             (not (match-string 3))
 777             (string-equal "" (match-string 3)))
 778         (progn (message "No subject line")
 779                nil)
 780       (let ((subject (match-string-no-properties 3))
 781             (list))
 782         (if (> (length subject) 41)
 783             (setq subject (substring subject 0 41)))
 784         (save-excursion
 785           (if all
 786               (goto-char (point-min)))
 787           (while (re-search-forward mh-scan-subject-regexp nil t)
 788             (let ((this-subject (match-string-no-properties 3)))
 789               (if (> (length this-subject) 41)
 790                   (setq this-subject (substring this-subject 0 41)))
 791               (if (string-equal this-subject subject)
 792                   (setq list (cons (mh-get-msg-num t) list))))))
 793         (cond
 794          (list
 795           ;; If we created a new sequence, add the initial message to it too.
 796           (if (not (member (mh-get-msg-num t) list))
 797               (setq list (cons (mh-get-msg-num t) list)))
 798           (if (assoc 'subject mh-seq-list) (mh-delete-seq 'subject))
 799           ;; sort the result into a sequence
 800           (let ((sorted-list (sort (copy-sequence list) 'mh-lessp)))
 801             (while sorted-list
 802               (mh-add-msgs-to-seq (car sorted-list) 'subject nil)
 803               (setq sorted-list (cdr sorted-list)))
 804             (safe-length list)))
 805          (t
 806           0))))))
 807
 808 (defun mh-subject-to-sequence-threaded (all)
 809   "Put all messages with the same subject in the 'subject sequence.
 810
 811 This function works when the folder is threaded. In this
 812 situation the subject could get truncated and so the normal
 813 matching doesn't work.
 814
 815 The parameter ALL is non-nil then all the messages in the buffer
 816 are considered, otherwise only the messages after the current one
 817 are taken into account."
 818   (let* ((cur (mh-get-msg-num nil))
 819          (subject (mh-thread-find-msg-subject cur))
 820          region msgs)
 821     (if (null subject)
 822         (and (message "No subject line") nil)
 823       (setq region (cons (if all (point-min) (point)) (point-max)))
 824       (mh-iterate-on-range msg region
 825         (when (eq (mh-thread-find-msg-subject msg) subject)
 826           (push msg msgs)))
 827       (setq msgs (sort msgs #'mh-lessp))
 828       (if (null msgs)
 829           0
 830         (when (assoc 'subject mh-seq-list)
 831           (mh-delete-seq 'subject))
 832         (mh-add-msgs-to-seq msgs 'subject)
 833         (length msgs)))))
 834
 835 (defun mh-thread-find-msg-subject (msg)
 836   "Find canonicalized subject of MSG.
 837 This function can only be used the folder is threaded."
 838   (ignore-errors
 839     (mh-message-subject
 840      (mh-container-message (gethash (gethash msg mh-thread-index-id-map)
 841                                     mh-thread-id-table)))))
 842
 843 (defun mh-edit-pick-expr (default)
 844   "With prefix arg edit a pick expression.
 845 If no prefix arg is given, then return DEFAULT."
 846   (let ((default-string (loop for x in default concat (format " %s" x))))
 847     (if (or current-prefix-arg (equal default-string ""))
 848         (mh-pick-args-list (read-string "Pick expression: "
 849                                         default-string))
 850       default)))
 851
 852 (defun mh-pick-args-list (s)
 853   "Form list by grouping elements in string S suitable for pick arguments.
 854 For example, the string \"-subject a b c -from Joe User
 855 <user@domain.com>\" is converted to (\"-subject\" \"a b c\"
 856 \"-from\" \"Joe User <user@domain.com>\""
 857   (let ((full-list (split-string s))
 858         current-arg collection arg-list)
 859     (while full-list
 860       (setq current-arg (car full-list))
 861       (if (null (string-match "^-" current-arg))
 862           (setq collection
 863                 (if (null collection)
 864                     current-arg
 865                   (format "%s %s" collection current-arg)))
 866         (when collection
 867           (setq arg-list (append arg-list (list collection)))
 868           (setq collection nil))
 869         (setq arg-list (append arg-list (list current-arg))))
 870       (setq full-list (cdr full-list)))
 871     (when collection
 872       (setq arg-list (append arg-list (list collection))))
 873     arg-list))
 874
 875 ;;;###mh-autoload
 876 (defun mh-narrow-to-subject (&optional pick-expr)
 877   "Limit to messages with same subject.
 878 With a prefix argument, edit PICK-EXPR.
 879
 880 Use \\<mh-folder-mode-map>\\[mh-widen] to undo this command."
 881   (interactive
 882    (list (mh-edit-pick-expr (mh-current-message-header-field 'subject))))
 883   (mh-narrow-to-header-field 'subject pick-expr))
 884
 885 ;;;###mh-autoload
 886 (defun mh-narrow-to-from (&optional pick-expr)
 887   "Limit to messages with the same \"From:\" field.
 888 With a prefix argument, edit PICK-EXPR.
 889
 890 Use \\<mh-folder-mode-map>\\[mh-widen] to undo this command."
 891   (interactive
 892    (list (mh-edit-pick-expr (mh-current-message-header-field 'from))))
 893   (mh-narrow-to-header-field 'from pick-expr))
 894
 895 ;;;###mh-autoload
 896 (defun mh-narrow-to-cc (&optional pick-expr)
 897   "Limit to messages with the same \"Cc:\" field.
 898 With a prefix argument, edit PICK-EXPR.
 899
 900 Use \\<mh-folder-mode-map>\\[mh-widen] to undo this command."
 901   (interactive
 902    (list (mh-edit-pick-expr (mh-current-message-header-field 'cc))))
 903   (mh-narrow-to-header-field 'cc pick-expr))
 904
 905 ;;;###mh-autoload
 906 (defun mh-narrow-to-to (&optional pick-expr)
 907   "Limit to messages with the same \"To:\" field.
 908 With a prefix argument, edit PICK-EXPR.
 909
 910 Use \\<mh-folder-mode-map>\\[mh-widen] to undo this command."
 911   (interactive
 912    (list (mh-edit-pick-expr (mh-current-message-header-field 'to))))
 913   (mh-narrow-to-header-field 'to pick-expr))
 914
 915 (defun mh-narrow-to-header-field (header-field pick-expr)
 916   "Limit to messages whose HEADER-FIELD match PICK-EXPR.
 917 The MH command pick is used to do the match."
 918   (let ((folder mh-current-folder)
 919         (original (mh-coalesce-msg-list
 920                    (mh-range-to-msg-list (cons (point-min) (point-max)))))
 921         (msg-list ()))
 922     (with-temp-buffer
 923       (apply #'mh-exec-cmd-output "pick" nil folder
 924              (append original (list "-list") pick-expr))
 925       (goto-char (point-min))
 926       (while (not (eobp))
 927         (let ((num (read-from-string
 928                     (buffer-substring (point) (line-end-position)))))
 929           (when (numberp (car num)) (push (car num) msg-list))
 930           (forward-line))))
 931     (if (null msg-list)
 932         (message "No matches")
 933       (when (assoc 'header mh-seq-list) (mh-delete-seq 'header))
 934       (mh-add-msgs-to-seq msg-list 'header)
 935       (mh-narrow-to-seq 'header))))
 936
 937 (defun mh-current-message-header-field (header-field)
 938   "Return a pick regexp to match HEADER-FIELD of the message at point."
 939   (let ((num (mh-get-msg-num nil)))
 940     (when num
 941       (let ((folder mh-current-folder))
 942         (with-temp-buffer
 943           (insert-file-contents-literally (mh-msg-filename num folder))
 944           (goto-char (point-min))
 945           (when (search-forward "\n\n" nil t)
 946             (narrow-to-region (point-min) (point)))
 947           (let* ((field (or (message-fetch-field (format "%s" header-field))
 948                             ""))
 949                  (field-option (format "-%s" header-field))
 950                  (patterns (loop for x in (split-string  field "[ ]*,[ ]*")
 951                                  unless (equal x "")
 952                                  collect (if (string-match "<\\(.*@.*\\)>" x)
 953                                              (match-string 1 x)
 954                                            x))))
 955             (when patterns
 956               (loop with accum = `(,field-option ,(car patterns))
 957                     for e in (cdr patterns)
 958                     do (setq accum `(,field-option ,e "-or" ,@accum))
 959                     finally return accum))))))))
 960
 961 ;;;###mh-autoload
 962 (defun mh-narrow-to-range (range)
 963   "Limit to RANGE.
 964
 965 Check the documentation of `mh-interactive-range' to see how
 966 RANGE is read in interactive use.
 967
 968 Use \\<mh-folder-mode-map>\\[mh-widen] to undo this command."
 969   (interactive (list (mh-interactive-range "Narrow to")))
 970   (when (assoc 'range mh-seq-list) (mh-delete-seq 'range))
 971   (mh-add-msgs-to-seq (mh-range-to-msg-list range) 'range)
 972   (mh-narrow-to-seq 'range))
 973
 974
 975 ;;;###mh-autoload
 976 (defun mh-delete-subject ()
 977   "Delete messages with same subject\\<mh-folder-mode-map>.
 978
 979 To delete messages faster, you can use this command to delete all
 980 the messages with the same subject as the current message. This
 981 command puts these messages in a sequence named \"subject\". You
 982 can undo this action by using \\[mh-undo] with a prefix argument
 983 and then specifying the \"subject\" sequence."
 984   (interactive)
 985   (let ((count (mh-subject-to-sequence nil)))
 986     (cond
 987      ((not count)                       ; No subject line, delete msg anyway
 988       (mh-delete-msg (mh-get-msg-num t)))
 989      ((= 0 count)                       ; No other msgs, delete msg anyway.
 990       (message "No other messages with same Subject following this one")
 991       (mh-delete-msg (mh-get-msg-num t)))
 992      (t                                 ; We have a subject sequence.
 993       (message "Marked %d messages for deletion" count)
 994       (mh-delete-msg 'subject)))))
 995
 996 ;;;###mh-autoload
 997 (defun mh-delete-subject-or-thread ()
 998   "Delete messages with same subject or thread\\<mh-folder-mode-map>.
 999
1000 To delete messages faster, you can use this command to delete all
1001 the messages with the same subject as the current message. This
1002 command puts these messages in a sequence named \"subject\". You
1003 can undo this action by using \\[mh-undo] with a prefix argument
1004 and then specifying the \"subject\" sequence.
1005
1006 However, if the buffer is displaying a threaded view of the
1007 folder then this command behaves like \\[mh-thread-delete]."
1008   (interactive)
1009   (if (memq 'unthread mh-view-ops)
1010       (mh-thread-delete)
1011     (mh-delete-subject)))
1012
1013 \f
1014
1015 ;;; Message threading:
1016
1017 (defmacro mh-thread-initialize-hash (var test)
1018   "Initialize the hash table in VAR.
1019 TEST is the test to use when creating a new hash table."
1020   (unless (symbolp var) (error "Expected a symbol: %s" var))
1021   `(if ,var (clrhash ,var) (setq ,var (make-hash-table :test ,test))))
1022
1023 (defun mh-thread-initialize ()
1024   "Make new hash tables, or clear them if already present."
1025   (mh-thread-initialize-hash mh-thread-id-hash #'equal)
1026   (mh-thread-initialize-hash mh-thread-subject-hash #'equal)
1027   (mh-thread-initialize-hash mh-thread-id-table #'eq)
1028   (mh-thread-initialize-hash mh-thread-id-index-map #'eq)
1029   (mh-thread-initialize-hash mh-thread-index-id-map #'eql)
1030   (mh-thread-initialize-hash mh-thread-scan-line-map #'eql)
1031   (mh-thread-initialize-hash mh-thread-subject-container-hash #'eq)
1032   (mh-thread-initialize-hash mh-thread-duplicates #'eq)
1033   (setq mh-thread-history ()))
1034
1035 (defsubst mh-thread-id-container (id)
1036   "Given ID, return the corresponding container in `mh-thread-id-table'.
1037 If no container exists then a suitable container is created and
1038 the id-table is updated."
1039   (when (not id)
1040     (error "1"))
1041   (or (gethash id mh-thread-id-table)
1042       (setf (gethash id mh-thread-id-table)
1043             (let ((message (mh-thread-make-message :id id)))
1044               (mh-thread-make-container :message message)))))
1045
1046 (defsubst mh-thread-remove-parent-link (child)
1047   "Remove parent link of CHILD if it exists."
1048   (let* ((child-container (if (mh-thread-container-p child)
1049                               child (mh-thread-id-container child)))
1050          (parent-container (mh-container-parent child-container)))
1051     (when parent-container
1052       (setf (mh-container-children parent-container)
1053             (loop for elem in (mh-container-children parent-container)
1054                   unless (eq child-container elem) collect elem))
1055       (setf (mh-container-parent child-container) nil))))
1056
1057 (defsubst mh-thread-add-link (parent child &optional at-end-p)
1058   "Add links so that PARENT becomes a parent of CHILD.
1059 Doesn't make any changes if CHILD is already an ancestor of
1060 PARENT. If optional argument AT-END-P is non-nil, the CHILD is
1061 added to the end of the children list of PARENT."
1062   (let ((parent-container (cond ((null parent) nil)
1063                                 ((mh-thread-container-p parent) parent)
1064                                 (t (mh-thread-id-container parent))))
1065         (child-container (if (mh-thread-container-p child)
1066                              child (mh-thread-id-container child))))
1067     (when (and parent-container
1068                (not (mh-thread-ancestor-p child-container parent-container))
1069                (not (mh-thread-ancestor-p parent-container child-container)))
1070       (mh-thread-remove-parent-link child-container)
1071       (cond ((not at-end-p)
1072              (push child-container (mh-container-children parent-container)))
1073             ((null (mh-container-children parent-container))
1074              (push child-container (mh-container-children parent-container)))
1075             (t (let ((last-child (mh-container-children parent-container)))
1076                  (while (cdr last-child)
1077                    (setq last-child (cdr last-child)))
1078                  (setcdr last-child (cons child-container nil)))))
1079       (setf (mh-container-parent child-container) parent-container))
1080     (unless parent-container
1081       (mh-thread-remove-parent-link child-container))))
1082
1083 (defun mh-thread-ancestor-p (ancestor successor)
1084   "Return t if ANCESTOR is really an ancestor of SUCCESSOR and nil otherwise.
1085 In the limit, the function returns t if ANCESTOR and SUCCESSOR
1086 are the same containers."
1087   (block nil
1088     (while successor
1089       (when (eq ancestor successor) (return t))
1090       (setq successor (mh-container-parent successor)))
1091     nil))
1092
1093 (defsubst mh-thread-get-message-container (message)
1094   "Return container which has MESSAGE in it.
1095 If there is no container present then a new container is
1096 allocated."
1097   (let* ((id (mh-message-id message))
1098          (container (gethash id mh-thread-id-table)))
1099     (cond (container (setf (mh-container-message container) message)
1100                      container)
1101           (t (setf (gethash id mh-thread-id-table)
1102                    (mh-thread-make-container :message message))))))
1103
1104 (defsubst mh-thread-get-message (id subject-re-p subject refs)
1105   "Return appropriate message.
1106 Otherwise update message already present to have the proper ID,
1107 SUBJECT-RE-P, SUBJECT and REFS fields."
1108   (let* ((container (gethash id mh-thread-id-table))
1109          (message (if container (mh-container-message container) nil)))
1110     (cond (message
1111            (setf (mh-message-subject-re-p message) subject-re-p)
1112            (setf (mh-message-subject message) subject)
1113            (setf (mh-message-id message) id)
1114            (setf (mh-message-references message) refs)
1115            message)
1116           (container
1117            (setf (mh-container-message container)
1118                  (mh-thread-make-message :id id :references refs
1119                                          :subject subject
1120                                          :subject-re-p subject-re-p)))
1121           (t (let ((message (mh-thread-make-message :id id :references refs
1122                                                     :subject-re-p subject-re-p
1123                                                     :subject subject)))
1124                (prog1 message
1125                  (mh-thread-get-message-container message)))))))
1126
1127 (defsubst mh-thread-canonicalize-id (id)
1128   "Produce canonical string representation for ID.
1129 This allows cheap string comparison with EQ."
1130   (or (and (equal id "") (copy-sequence ""))
1131       (gethash id mh-thread-id-hash)
1132       (setf (gethash id mh-thread-id-hash) id)))
1133
1134 (defsubst mh-thread-prune-subject (subject)
1135   "Prune leading Re:'s, Fwd:'s etc. and trailing (fwd)'s from SUBJECT.
1136 If the result after pruning is not the empty string then it is
1137 canonicalized so that subjects can be tested for equality with
1138 eq. This is done so that all the messages without a subject are
1139 not put into a single thread."
1140   (let ((case-fold-search t)
1141         (subject-pruned-flag nil))
1142     ;; Prune subject leader
1143     (while (or (string-match "^[ \t]*\\(re\\|fwd?\\)\\(\\[[0-9]*\\]\\)?:[ \t]*"
1144                              subject)
1145                (string-match "^[ \t]*\\[[^\\]][ \t]*" subject))
1146       (setq subject-pruned-flag t)
1147       (setq subject (substring subject (match-end 0))))
1148     ;; Prune subject trailer
1149     (while (or (string-match "(fwd)$" subject)
1150                (string-match "[ \t]+$" subject))
1151       (setq subject-pruned-flag t)
1152       (setq subject (substring subject 0 (match-beginning 0))))
1153     ;; Canonicalize subject only if it is non-empty
1154     (cond ((equal subject "") (values subject subject-pruned-flag))
1155           (t (values
1156               (or (gethash subject mh-thread-subject-hash)
1157                   (setf (gethash subject mh-thread-subject-hash) subject))
1158               subject-pruned-flag)))))
1159
1160 (defun mh-thread-container-subject (container)
1161   "Return the subject of CONTAINER.
1162 If CONTAINER is empty return the subject info of one of its
1163 children."
1164   (cond ((and (mh-container-message container)
1165               (mh-message-id (mh-container-message container)))
1166          (mh-message-subject (mh-container-message container)))
1167         (t (block nil
1168              (dolist (kid (mh-container-children container))
1169                (when (and (mh-container-message kid)
1170                           (mh-message-id (mh-container-message kid)))
1171                  (let ((kid-message (mh-container-message kid)))
1172                    (return (mh-message-subject kid-message)))))
1173              (error "This can't happen!")))))
1174
1175 (defun mh-thread-rewind-pruning ()
1176   "Restore the thread tree to its state before pruning."
1177   (while mh-thread-history
1178     (let ((action (pop mh-thread-history)))
1179       (cond ((eq (car action) 'DROP)
1180              (mh-thread-remove-parent-link (cadr action))
1181              (mh-thread-add-link (caddr action) (cadr action)))
1182             ((eq (car action) 'PROMOTE)
1183              (let ((node (cadr action))
1184                    (parent (caddr action))
1185                    (children (cdddr action)))
1186                (dolist (child children)
1187                  (mh-thread-remove-parent-link child)
1188                  (mh-thread-add-link node child))
1189                (mh-thread-add-link parent node)))
1190             ((eq (car action) 'SUBJECT)
1191              (let ((node (cadr action)))
1192                (mh-thread-remove-parent-link node)
1193                (setf (mh-container-real-child-p node) t)))))))
1194
1195 (defun mh-thread-prune-containers (roots)
1196   "Prune empty containers in the containers ROOTS."
1197   (let ((dfs-ordered-nodes ())
1198         (work-list roots))
1199     (while work-list
1200       (let ((node (pop work-list)))
1201         (dolist (child (mh-container-children node))
1202           (push child work-list))
1203         (push node dfs-ordered-nodes)))
1204     (while dfs-ordered-nodes
1205       (let ((node (pop dfs-ordered-nodes)))
1206         (cond ((gethash (mh-message-id (mh-container-message node))
1207                         mh-thread-id-index-map)
1208                ;; Keep it
1209                (setf (mh-container-children node)
1210                      (mh-thread-sort-containers (mh-container-children node))))
1211               ((and (mh-container-children node)
1212                     (or (null (cdr (mh-container-children node)))
1213                         (mh-container-parent node)))
1214                ;; Promote kids
1215                (let ((children ()))
1216                  (dolist (kid (mh-container-children node))
1217                    (mh-thread-remove-parent-link kid)
1218                    (mh-thread-add-link (mh-container-parent node) kid)
1219                    (push kid children))
1220                  (push `(PROMOTE ,node ,(mh-container-parent node) ,@children)
1221                        mh-thread-history)
1222                  (mh-thread-remove-parent-link node)))
1223               ((mh-container-children node)
1224                ;; Promote the first orphan to parent and add the other kids as
1225                ;; his children
1226                (setf (mh-container-children node)
1227                      (mh-thread-sort-containers (mh-container-children node)))
1228                (let ((new-parent (car (mh-container-children node)))
1229                      (other-kids (cdr (mh-container-children node))))
1230                  (mh-thread-remove-parent-link new-parent)
1231                  (dolist (kid other-kids)
1232                    (mh-thread-remove-parent-link kid)
1233                    (setf (mh-container-real-child-p kid) nil)
1234                    (mh-thread-add-link new-parent kid t))
1235                  (push `(PROMOTE ,node ,(mh-container-parent node)
1236                                  ,new-parent ,@other-kids)
1237                        mh-thread-history)
1238                  (mh-thread-remove-parent-link node)))
1239               (t
1240                ;; Drop it
1241                (push `(DROP ,node ,(mh-container-parent node))
1242                      mh-thread-history)
1243                (mh-thread-remove-parent-link node)))))
1244     (let ((results ()))
1245       (maphash #'(lambda (k v)
1246                    (declare (ignore k))
1247                    (when (and (null (mh-container-parent v))
1248                               (gethash (mh-message-id (mh-container-message v))
1249                                        mh-thread-id-index-map))
1250                      (push v results)))
1251                mh-thread-id-table)
1252       (mh-thread-sort-containers results))))
1253
1254 (defun mh-thread-sort-containers (containers)
1255   "Sort a list of message CONTAINERS to be in ascending order wrt index."
1256   (sort containers
1257         #'(lambda (x y)
1258             (when (and (mh-container-message x) (mh-container-message y))
1259               (let* ((id-x (mh-message-id (mh-container-message x)))
1260                      (id-y (mh-message-id (mh-container-message y)))
1261                      (index-x (gethash id-x mh-thread-id-index-map))
1262                      (index-y (gethash id-y mh-thread-id-index-map)))
1263                 (and (integerp index-x) (integerp index-y)
1264                      (< index-x index-y)))))))
1265
1266 (defsubst mh-thread-group-by-subject (roots)
1267   "Group the set of message containers, ROOTS based on subject.
1268 Bug: Check for and make sure that something without Re: is made
1269 the parent in preference to something that has it."
1270   (clrhash mh-thread-subject-container-hash)
1271   (let ((results ()))
1272     (dolist (root roots)
1273       (let* ((subject (mh-thread-container-subject root))
1274              (parent (gethash subject mh-thread-subject-container-hash)))
1275         (cond (parent (mh-thread-remove-parent-link root)
1276                       (mh-thread-add-link parent root t)
1277                       (setf (mh-container-real-child-p root) nil)
1278                       (push `(SUBJECT ,root) mh-thread-history))
1279               (t
1280                (setf (gethash subject mh-thread-subject-container-hash) root)
1281                (push root results)))))
1282     (nreverse results)))
1283
1284 (defun mh-thread-process-in-reply-to (reply-to-header)
1285   "Extract message id's from REPLY-TO-HEADER.
1286 Ideally this should have some regexp which will try to guess if a
1287 string between < and > is a message id and not an email address.
1288 For now it will take the last string inside angles."
1289   (let ((end (mh-search-from-end ?> reply-to-header)))
1290     (when (numberp end)
1291       (let ((begin (mh-search-from-end ?< (substring reply-to-header 0 end))))
1292         (when (numberp begin)
1293           (list (substring reply-to-header begin (1+ end))))))))
1294
1295 (defun mh-thread-set-tables (folder)
1296   "Use the tables of FOLDER in current buffer."
1297   (flet ((mh-get-table (symbol)
1298                        (save-excursion
1299                          (set-buffer folder)
1300                          (symbol-value symbol))))
1301     (setq mh-thread-id-hash (mh-get-table 'mh-thread-id-hash))
1302     (setq mh-thread-subject-hash (mh-get-table 'mh-thread-subject-hash))
1303     (setq mh-thread-id-table (mh-get-table 'mh-thread-id-table))
1304     (setq mh-thread-id-index-map (mh-get-table 'mh-thread-id-index-map))
1305     (setq mh-thread-index-id-map (mh-get-table 'mh-thread-index-id-map))
1306     (setq mh-thread-scan-line-map (mh-get-table 'mh-thread-scan-line-map))
1307     (setq mh-thread-subject-container-hash
1308           (mh-get-table 'mh-thread-subject-container-hash))
1309     (setq mh-thread-duplicates (mh-get-table 'mh-thread-duplicates))
1310     (setq mh-thread-history (mh-get-table 'mh-thread-history))))
1311
1312 (defsubst mh-thread-update-id-index-maps (id index)
1313   "Message with id, ID is the message in INDEX.
1314 The function also checks for duplicate messages (that is multiple
1315 messages with the same ID). These messages are put in the
1316 `mh-thread-duplicates' hash table."
1317   (let ((old-index (gethash id mh-thread-id-index-map)))
1318     (when old-index (push old-index (gethash id mh-thread-duplicates)))
1319     (setf (gethash id mh-thread-id-index-map) index)
1320     (setf (gethash index mh-thread-index-id-map) id)))
1321
1322 \f
1323
1324 ;;; Generate Threads...
1325
1326 (defvar mh-message-id-regexp "^<.*@.*>$"
1327   "Regexp to recognize whether a string is a message identifier.")
1328
1329 (defun mh-thread-generate (folder msg-list)
1330   "Scan FOLDER to get info for threading.
1331 Only information about messages in MSG-LIST are added to the tree."
1332   (with-temp-buffer
1333     (mh-thread-set-tables folder)
1334     (when msg-list
1335       (apply
1336        #'call-process (expand-file-name mh-scan-prog mh-progs) nil '(t nil) nil
1337        "-width" "10000" "-format"
1338        "%(msg)\n%{message-id}\n%{references}\n%{in-reply-to}\n%{subject}\n"
1339        folder (mapcar #'(lambda (x) (format "%s" x)) msg-list)))
1340     (goto-char (point-min))
1341     (let ((roots ())
1342           (case-fold-search t))
1343       (block nil
1344         (while (not (eobp))
1345           (block process-message
1346             (let* ((index-line
1347                     (prog1 (buffer-substring (point) (line-end-position))
1348                       (forward-line)))
1349                    (index (car (read-from-string index-line)))
1350                    (id (prog1 (buffer-substring (point) (line-end-position))
1351                          (forward-line)))
1352                    (refs (prog1 (buffer-substring (point) (line-end-position))
1353                            (forward-line)))
1354                    (in-reply-to (prog1 (buffer-substring (point)
1355                                                          (line-end-position))
1356                                   (forward-line)))
1357                    (subject (prog1
1358                                 (buffer-substring (point) (line-end-position))
1359                               (forward-line)))
1360                    (subject-re-p nil))
1361               (unless (gethash index mh-thread-scan-line-map)
1362                 (return-from process-message))
1363               (unless (integerp index) (return)) ;Error message here
1364               (multiple-value-setq (subject subject-re-p)
1365                 (mh-thread-prune-subject subject))
1366               (setq in-reply-to (mh-thread-process-in-reply-to in-reply-to))
1367               (setq refs (loop for x in (append (split-string refs) in-reply-to)
1368                                when (string-match mh-message-id-regexp x)
1369                                collect x))
1370               (setq id (mh-thread-canonicalize-id id))
1371               (mh-thread-update-id-index-maps id index)
1372               (setq refs (mapcar #'mh-thread-canonicalize-id refs))
1373               (mh-thread-get-message id subject-re-p subject refs)
1374               (do ((ancestors refs (cdr ancestors)))
1375                   ((null (cdr ancestors))
1376                    (when (car ancestors)
1377                      (mh-thread-remove-parent-link id)
1378                      (mh-thread-add-link (car ancestors) id)))
1379                 (mh-thread-add-link (car ancestors) (cadr ancestors)))))))
1380       (maphash #'(lambda (k v)
1381                    (declare (ignore k))
1382                    (when (null (mh-container-parent v))
1383                      (push v roots)))
1384                mh-thread-id-table)
1385       (setq roots (mh-thread-prune-containers roots))
1386       (prog1 (setq roots (mh-thread-group-by-subject roots))
1387         (let ((history mh-thread-history))
1388           (set-buffer folder)
1389           (setq mh-thread-history history))))))
1390
1391 ;;;###mh-autoload
1392 (defun mh-thread-inc (folder start-point)
1393   "Update thread tree for FOLDER.
1394 All messages after START-POINT are added to the thread tree."
1395   (mh-thread-rewind-pruning)
1396   (mh-remove-all-notation)
1397   (goto-char start-point)
1398   (let ((msg-list ()))
1399     (while (not (eobp))
1400       (let ((index (mh-get-msg-num nil)))
1401         (when (numberp index)
1402           (push index msg-list)
1403           (setf (gethash index mh-thread-scan-line-map)
1404                 (mh-thread-parse-scan-line)))
1405         (forward-line)))
1406     (let ((thread-tree (mh-thread-generate folder msg-list))
1407           (buffer-read-only nil)
1408           (old-buffer-modified-flag (buffer-modified-p)))
1409       (delete-region (point-min) (point-max))
1410       (mh-thread-print-scan-lines thread-tree)
1411       (mh-notate-user-sequences)
1412       (mh-notate-deleted-and-refiled)
1413       (mh-notate-cur)
1414       (set-buffer-modified-p old-buffer-modified-flag))))
1415
1416 (defun mh-thread-generate-scan-lines (tree level)
1417   "Generate scan lines.
1418 TREE is the hierarchical tree of messages, SCAN-LINE-MAP maps
1419 message indices to the corresponding scan lines and LEVEL used to
1420 determine indentation of the message."
1421   (cond ((null tree) nil)
1422         ((mh-thread-container-p tree)
1423          (let* ((message (mh-container-message tree))
1424                 (id (mh-message-id message))
1425                 (index (gethash id mh-thread-id-index-map))
1426                 (duplicates (gethash id mh-thread-duplicates))
1427                 (new-level (+ level 2))
1428                 (dupl-flag t)
1429                 (force-angle-flag nil)
1430                 (increment-level-flag nil))
1431            (dolist (scan-line (mapcar (lambda (x)
1432                                         (gethash x mh-thread-scan-line-map))
1433                                       (reverse (cons index duplicates))))
1434              (when scan-line
1435                (when (and dupl-flag (equal level 0)
1436                           (mh-thread-ancestor-p mh-thread-last-ancestor tree))
1437                  (setq level (+ level 2)
1438                        new-level (+ new-level 2)
1439                        force-angle-flag t))
1440                (when (equal level 0)
1441                  (setq mh-thread-last-ancestor tree)
1442                  (while (mh-container-parent mh-thread-last-ancestor)
1443                    (setq mh-thread-last-ancestor
1444                          (mh-container-parent mh-thread-last-ancestor))))
1445                (let* ((lev (if dupl-flag level new-level))
1446                       (square-flag (or (and (mh-container-real-child-p tree)
1447                                             (not force-angle-flag)
1448                                             dupl-flag)
1449                                        (equal lev 0))))
1450                  (insert (car scan-line)
1451                          (format (format "%%%ss" lev) "")
1452                          (if square-flag "[" "<")
1453                          (cadr scan-line)
1454                          (if square-flag "]" ">")
1455                          (truncate-string-to-width
1456                           (caddr scan-line) (- mh-thread-body-width lev))
1457                          "\n"))
1458                (setq increment-level-flag t)
1459                (setq dupl-flag nil)))
1460            (unless increment-level-flag (setq new-level level))
1461            (dolist (child (mh-container-children tree))
1462              (mh-thread-generate-scan-lines child new-level))))
1463         (t (let ((nlevel (+ level 2)))
1464              (dolist (ch tree)
1465                (mh-thread-generate-scan-lines ch nlevel))))))
1466
1467 ;; Another and may be better approach would be to generate all the info from
1468 ;; the scan which generates the threading info. For now this will have to do.
1469 (defun mh-thread-parse-scan-line (&optional string)
1470   "Parse a scan line.
1471 If optional argument STRING is given then that is assumed to be
1472 the scan line. Otherwise uses the line at point as the scan line
1473 to parse."
1474   (let* ((string (or string
1475                      (buffer-substring-no-properties (line-beginning-position)
1476                                                      (line-end-position))))
1477          (address-start (+ mh-cmd-note mh-scan-field-from-start-offset))
1478          (body-start (+ mh-cmd-note mh-scan-field-from-end-offset))
1479          (first-string (substring string 0 address-start)))
1480     (list first-string
1481           (substring string address-start (- body-start 2))
1482           (substring string body-start)
1483           string)))
1484
1485 ;;;###mh-autoload
1486 (defun mh-thread-update-scan-line-map (msg notation offset)
1487   "In threaded view update `mh-thread-scan-line-map'.
1488 MSG is the message being notated with NOTATION at OFFSET."
1489   (let* ((msg (or msg (mh-get-msg-num nil)))
1490          (cur-scan-line (and mh-thread-scan-line-map
1491                              (gethash msg mh-thread-scan-line-map)))
1492          (old-scan-lines (loop for map in mh-thread-scan-line-map-stack
1493                                collect (and map (gethash msg map)))))
1494     (when cur-scan-line
1495       (setf (aref (car cur-scan-line) offset) notation))
1496     (dolist (line old-scan-lines)
1497       (when line (setf (aref (car line) offset) notation)))))
1498
1499 ;;;###mh-autoload
1500 (defun mh-thread-add-spaces (count)
1501   "Add COUNT spaces to each scan line in `mh-thread-scan-line-map'."
1502   (let ((spaces (format (format "%%%ss" count) "")))
1503     (while (not (eobp))
1504       (let* ((msg-num (mh-get-msg-num nil))
1505              (old-line (nth 3 (gethash msg-num mh-thread-scan-line-map))))
1506         (when (numberp msg-num)
1507           (setf (gethash msg-num mh-thread-scan-line-map)
1508                 (mh-thread-parse-scan-line (format "%s%s" spaces old-line)))))
1509       (forward-line 1))))
1510
1511 (defun mh-thread-print-scan-lines (thread-tree)
1512   "Print scan lines in THREAD-TREE in threaded mode."
1513   (let ((mh-thread-body-width (- (window-width) mh-cmd-note
1514                                  (1- mh-scan-field-subject-start-offset)))
1515         (mh-thread-last-ancestor nil))
1516     (if (null mh-index-data)
1517         (mh-thread-generate-scan-lines thread-tree -2)
1518       (loop for x in (mh-index-group-by-folder)
1519             do (let* ((old-map mh-thread-scan-line-map)
1520                       (mh-thread-scan-line-map (make-hash-table)))
1521                  (setq mh-thread-last-ancestor nil)
1522                  (loop for msg in (cdr x)
1523                        do (let ((v (gethash msg old-map)))
1524                             (when v
1525                               (setf (gethash msg mh-thread-scan-line-map) v))))
1526                  (when (> (hash-table-count mh-thread-scan-line-map) 0)
1527                    (insert (if (bobp) "" "\n") (car x) "\n")
1528                    (mh-thread-generate-scan-lines thread-tree -2))))
1529       (mh-index-create-imenu-index))))
1530
1531 (defun mh-thread-folder ()
1532   "Generate thread view of folder."
1533   (message "Threading %s..." (buffer-name))
1534   (mh-thread-initialize)
1535   (goto-char (point-min))
1536   (mh-remove-all-notation)
1537   (let ((msg-list ()))
1538     (mh-iterate-on-range msg (cons (point-min) (point-max))
1539       (setf (gethash msg mh-thread-scan-line-map) (mh-thread-parse-scan-line))
1540       (push msg msg-list))
1541     (let* ((range (mh-coalesce-msg-list msg-list))
1542            (thread-tree (mh-thread-generate (buffer-name) range)))
1543       (delete-region (point-min) (point-max))
1544       (mh-thread-print-scan-lines thread-tree)
1545       (mh-notate-user-sequences)
1546       (mh-notate-deleted-and-refiled)
1547       (mh-notate-cur)
1548       (message "Threading %s...done" (buffer-name)))))
1549
1550 ;;;###mh-autoload
1551 (defun mh-toggle-threads ()
1552   "Toggle threaded view of folder."
1553   (interactive)
1554   (let ((msg-at-point (mh-get-msg-num nil))
1555         (old-buffer-modified-flag (buffer-modified-p))
1556         (buffer-read-only nil))
1557     (cond ((memq 'unthread mh-view-ops)
1558            (unless (mh-valid-view-change-operation-p 'unthread)
1559              (error "Can't unthread folder"))
1560            (let ((msg-list ()))
1561              (goto-char (point-min))
1562              (while (not (eobp))
1563                (let ((index (mh-get-msg-num nil)))
1564                  (when index
1565                    (push index msg-list)))
1566                (forward-line))
1567              (mh-scan-folder mh-current-folder
1568                              (mapcar #'(lambda (x) (format "%s" x))
1569                                      (mh-coalesce-msg-list msg-list))
1570                              t))
1571            (when mh-index-data
1572              (mh-index-insert-folder-headers)
1573              (mh-notate-cur)))
1574           (t (mh-thread-folder)
1575              (push 'unthread mh-view-ops)))
1576     (when msg-at-point (mh-goto-msg msg-at-point t t))
1577     (set-buffer-modified-p old-buffer-modified-flag)
1578     (mh-recenter nil)))
1579
1580 ;;;###mh-autoload
1581 (defun mh-thread-forget-message (index)
1582   "Forget the message INDEX from the threading tables."
1583   (let* ((id (gethash index mh-thread-index-id-map))
1584          (id-index (gethash id mh-thread-id-index-map))
1585          (duplicates (gethash id mh-thread-duplicates)))
1586     (remhash index mh-thread-index-id-map)
1587     (remhash index mh-thread-scan-line-map)
1588     (cond ((and (eql index id-index) (null duplicates))
1589            (remhash id mh-thread-id-index-map))
1590           ((eql index id-index)
1591            (setf (gethash id mh-thread-id-index-map) (car duplicates))
1592            (setf (gethash (car duplicates) mh-thread-index-id-map) id)
1593            (setf (gethash id mh-thread-duplicates) (cdr duplicates)))
1594           (t
1595            (setf (gethash id mh-thread-duplicates)
1596                  (remove index duplicates))))))
1597
1598 \f
1599
1600 ;;; Operations on threads
1601
1602 (defun mh-thread-current-indentation-level ()
1603   "Find the number of spaces by which current message is indented."
1604   (save-excursion
1605     (let ((address-start-offset (+ mh-cmd-note mh-scan-date-flag-width
1606                                    mh-scan-date-width 1))
1607           (level 0))
1608       (beginning-of-line)
1609       (forward-char address-start-offset)
1610       (while (char-equal (char-after) ? )
1611         (incf level)
1612         (forward-char))
1613       level)))
1614
1615 ;;;###mh-autoload
1616 (defun mh-thread-next-sibling (&optional previous-flag)
1617   "Display next sibling.
1618
1619 With non-nil optional argument PREVIOUS-FLAG jump to the previous
1620 sibling."
1621   (interactive)
1622   (cond ((not (memq 'unthread mh-view-ops))
1623          (error "Folder isn't threaded"))
1624         ((eobp)
1625          (error "No message at point")))
1626   (beginning-of-line)
1627   (let ((point (point))
1628         (done nil)
1629         (my-level (mh-thread-current-indentation-level)))
1630     (while (and (not done)
1631                 (equal (forward-line (if previous-flag -1 1)) 0)
1632                 (not (eobp)))
1633       (let ((level (mh-thread-current-indentation-level)))
1634         (cond ((equal level my-level)
1635                (setq done 'success))
1636               ((< level my-level)
1637                (message "No %s sibling" (if previous-flag "previous" "next"))
1638                (setq done 'failure)))))
1639     (cond ((eq done 'success) (mh-maybe-show))
1640           ((eq done 'failure) (goto-char point))
1641           (t (message "No %s sibling" (if previous-flag "previous" "next"))
1642              (goto-char point)))))
1643
1644 ;;;###mh-autoload
1645 (defun mh-thread-previous-sibling ()
1646   "Display previous sibling."
1647   (interactive)
1648   (mh-thread-next-sibling t))
1649
1650 (defun mh-thread-immediate-ancestor ()
1651   "Jump to immediate ancestor in thread tree."
1652   (beginning-of-line)
1653   (let ((point (point))
1654         (ancestor-level (- (mh-thread-current-indentation-level) 2))
1655         (done nil))
1656     (if (< ancestor-level 0)
1657         nil
1658       (while (and (not done) (equal (forward-line -1) 0))
1659         (when (equal ancestor-level (mh-thread-current-indentation-level))
1660           (setq done t)))
1661       (unless done
1662         (goto-char point))
1663       done)))
1664
1665 ;;;###mh-autoload
1666 (defun mh-thread-ancestor (&optional thread-root-flag)
1667   "Display ancestor of current message.
1668
1669 If you do not care for the way a particular thread has turned,
1670 you can move up the chain of messages with this command. This
1671 command can also take a prefix argument THREAD-ROOT-FLAG to jump
1672 to the message that started everything."
1673   (interactive "P")
1674   (beginning-of-line)
1675   (cond ((not (memq 'unthread mh-view-ops))
1676          (error "Folder isn't threaded"))
1677         ((eobp)
1678          (error "No message at point")))
1679   (let ((current-level (mh-thread-current-indentation-level)))
1680     (cond (thread-root-flag
1681            (while (mh-thread-immediate-ancestor))
1682            (mh-maybe-show))
1683           ((equal current-level 1)
1684            (message "Message has no ancestor"))
1685           (t (mh-thread-immediate-ancestor)
1686              (mh-maybe-show)))))
1687
1688 (defun mh-thread-find-children ()
1689   "Return a region containing the current message and its children.
1690 The result is returned as a list of two elements. The first is
1691 the point at the start of the region and the second is the point
1692 at the end."
1693   (beginning-of-line)
1694   (if (eobp)
1695       nil
1696     (let ((address-start-offset (+ mh-cmd-note mh-scan-date-flag-width
1697                                    mh-scan-date-width 1))
1698           (level (mh-thread-current-indentation-level))
1699           spaces begin)
1700       (setq begin (point))
1701       (setq spaces (format (format "%%%ss" (1+ level)) ""))
1702       (forward-line)
1703       (block nil
1704         (while (not (eobp))
1705           (forward-char address-start-offset)
1706           (unless (equal (string-match spaces (buffer-substring-no-properties
1707                                                (point) (line-end-position)))
1708                          0)
1709             (beginning-of-line)
1710             (backward-char)
1711             (return))
1712           (forward-line)))
1713       (list begin (point)))))
1714
1715 ;;;###mh-autoload
1716 (defun mh-thread-delete ()
1717   "Delete thread."
1718   (interactive)
1719   (cond ((not (memq 'unthread mh-view-ops))
1720          (error "Folder isn't threaded"))
1721         ((eobp)
1722          (error "No message at point"))
1723         (t (let ((region (mh-thread-find-children)))
1724              (mh-iterate-on-messages-in-region () (car region) (cadr region)
1725                (mh-delete-a-msg nil))
1726              (mh-next-msg)))))
1727
1728 ;;;###mh-autoload
1729 (defun mh-thread-refile (folder)
1730   "Refile (output) thread into FOLDER."
1731   (interactive (list (intern (mh-prompt-for-refile-folder))))
1732   (cond ((not (memq 'unthread mh-view-ops))
1733          (error "Folder isn't threaded"))
1734         ((eobp)
1735          (error "No message at point"))
1736         (t (let ((region (mh-thread-find-children)))
1737              (mh-iterate-on-messages-in-region () (car region) (cadr region)
1738                (mh-refile-a-msg nil folder))
1739              (mh-next-msg)))))
1740
1741 \f
1742
1743 ;; Tick mark handling
1744
1745 ;;;###mh-autoload
1746 (defun mh-toggle-tick (range)
1747   "Toggle tick mark of RANGE.
1748
1749 This command adds messages to the \"tick\" sequence (which you can customize
1750 via the option `mh-tick-seq'). This sequence can be viewed later with the
1751 \\[mh-index-ticked-messages] command.
1752
1753 Check the documentation of `mh-interactive-range' to see how RANGE is read in
1754 interactive use."
1755   (interactive (list (mh-interactive-range "Tick")))
1756   (unless mh-tick-seq
1757     (error "Enable ticking by customizing `mh-tick-seq'"))
1758   (let* ((tick-seq (mh-find-seq mh-tick-seq))
1759          (tick-seq-msgs (mh-seq-msgs tick-seq))
1760          (ticked ())
1761          (unticked ()))
1762     (mh-iterate-on-range msg range
1763       (cond ((member msg tick-seq-msgs)
1764              (push msg unticked)
1765              (setcdr tick-seq (delq msg (cdr tick-seq)))
1766              (when (null (cdr tick-seq)) (setq mh-last-seq-used nil))
1767              (mh-remove-sequence-notation msg (mh-colors-in-use-p)))
1768             (t
1769              (push msg ticked)
1770              (setq mh-last-seq-used mh-tick-seq)
1771              (let ((mh-seq-list (cons `(,mh-tick-seq ,msg) mh-seq-list)))
1772                (mh-add-sequence-notation msg (mh-colors-in-use-p))))))
1773     (mh-add-msgs-to-seq ticked mh-tick-seq nil t)
1774     (mh-undefine-sequence mh-tick-seq unticked)
1775     (when mh-index-data
1776       (mh-index-add-to-sequence mh-tick-seq ticked)
1777       (mh-index-delete-from-sequence mh-tick-seq unticked))))
1778
1779 ;;;###mh-autoload
1780 (defun mh-narrow-to-tick ()
1781   "Limit to ticked messages.
1782
1783 What this command does is show only those messages that are in
1784 the \"tick\" sequence (which you can customize via the
1785 `mh-tick-seq' option) in the MH-Folder buffer. In addition, it
1786 limits further MH-E searches to just those messages. When you
1787 want to widen the view to all your messages again, use
1788 \\[mh-widen]."
1789   (interactive)
1790   (cond ((not mh-tick-seq)
1791          (error "Enable ticking by customizing `mh-tick-seq'"))
1792         ((null (mh-seq-msgs (mh-find-seq mh-tick-seq)))
1793          (message "No messages in %s sequence" mh-tick-seq))
1794         (t (mh-narrow-to-seq mh-tick-seq))))
1795
1796 (provide 'mh-seq)
1797
1798 ;; Local Variables:
1799 ;; indent-tabs-mode: nil
1800 ;; sentence-end-double-space: nil
1801 ;; End:
1802
1803 ;; arch-tag: 8e952711-01a2-485b-bf21-c9e3ad4de942
1804 ;;; mh-seq.el ends here