lisp/gnus/gnus-spec.el

   1 ;;; gnus-spec.el --- format spec functions for Gnus
   2 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
   3 ;;        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 (require 'gnus)
  32
  33 (defcustom gnus-use-correct-string-widths (featurep 'xemacs)
  34   "*If non-nil, use correct functions for dealing with wide characters."
  35   :version "21.4"
  36   :group 'gnus-format
  37   :type 'boolean)
  38
  39 (defcustom gnus-make-format-preserve-properties (featurep 'xemacs)
  40   "*If non-nil, use a replacement `format' function which preserves
  41 text properties. This is only needed on XEmacs, as FSF Emacs does this anyway."
  42   :version "21.4"
  43   :group 'gnus-format
  44   :type 'boolean)
  45
  46 ;;; Internal variables.
  47
  48 (defvar gnus-summary-mark-positions nil)
  49 (defvar gnus-group-mark-positions nil)
  50 (defvar gnus-group-indentation "")
  51
  52 ;; Format specs.  The chunks below are the machine-generated forms
  53 ;; that are to be evaled as the result of the default format strings.
  54 ;; We write them in here to get them byte-compiled.  That way the
  55 ;; default actions will be quite fast, while still retaining the full
  56 ;; flexibility of the user-defined format specs.
  57
  58 ;; First we have lots of dummy defvars to let the compiler know these
  59 ;; are really dynamic variables.
  60
  61 (defvar gnus-tmp-unread)
  62 (defvar gnus-tmp-replied)
  63 (defvar gnus-tmp-score-char)
  64 (defvar gnus-tmp-indentation)
  65 (defvar gnus-tmp-opening-bracket)
  66 (defvar gnus-tmp-lines)
  67 (defvar gnus-tmp-name)
  68 (defvar gnus-tmp-closing-bracket)
  69 (defvar gnus-tmp-subject-or-nil)
  70 (defvar gnus-tmp-subject)
  71 (defvar gnus-tmp-marked)
  72 (defvar gnus-tmp-marked-mark)
  73 (defvar gnus-tmp-subscribed)
  74 (defvar gnus-tmp-process-marked)
  75 (defvar gnus-tmp-number-of-unread)
  76 (defvar gnus-tmp-group-name)
  77 (defvar gnus-tmp-group)
  78 (defvar gnus-tmp-article-number)
  79 (defvar gnus-tmp-unread-and-unselected)
  80 (defvar gnus-tmp-news-method)
  81 (defvar gnus-tmp-news-server)
  82 (defvar gnus-tmp-article-number)
  83 (defvar gnus-mouse-face)
  84 (defvar gnus-mouse-face-prop)
  85 (defvar gnus-tmp-header)
  86 (defvar gnus-tmp-from)
  87
  88 (defun gnus-summary-line-format-spec ()
  89   (insert gnus-tmp-unread gnus-tmp-replied
  90           gnus-tmp-score-char gnus-tmp-indentation)
  91   (gnus-put-text-property
  92    (point)
  93    (progn
  94      (insert
  95       (format "%c%4s: %-23s%c" gnus-tmp-opening-bracket gnus-tmp-lines
  96               (let ((val
  97                      (inline
  98                        (gnus-summary-from-or-to-or-newsgroups
  99                         gnus-tmp-header gnus-tmp-from))))
 100                 (if (> (length val) 23)
 101                     (substring val 0 23)
 102                   val))
 103               gnus-tmp-closing-bracket))
 104      (point))
 105    gnus-mouse-face-prop gnus-mouse-face)
 106   (insert " " gnus-tmp-subject-or-nil "\n"))
 107
 108 (defvar gnus-summary-line-format-spec
 109   (gnus-byte-code 'gnus-summary-line-format-spec))
 110
 111 (defun gnus-summary-dummy-line-format-spec ()
 112   (insert "*  ")
 113   (gnus-put-text-property
 114    (point)
 115    (progn
 116      (insert ":                          :")
 117      (point))
 118    gnus-mouse-face-prop gnus-mouse-face)
 119   (insert " " gnus-tmp-subject "\n"))
 120
 121 (defvar gnus-summary-dummy-line-format-spec
 122   (gnus-byte-code 'gnus-summary-dummy-line-format-spec))
 123
 124 (defun gnus-group-line-format-spec ()
 125   (insert gnus-tmp-marked-mark gnus-tmp-subscribed
 126           gnus-tmp-process-marked
 127           gnus-group-indentation
 128           (format "%5s: " gnus-tmp-number-of-unread))
 129   (gnus-put-text-property
 130    (point)
 131    (progn
 132      (insert gnus-tmp-group "\n")
 133      (1- (point)))
 134    gnus-mouse-face-prop gnus-mouse-face))
 135 (defvar gnus-group-line-format-spec
 136   (gnus-byte-code 'gnus-group-line-format-spec))
 137
 138 (defvar gnus-format-specs
 139   `((version . ,emacs-version)
 140     (gnus-version . ,(gnus-continuum-version))
 141     (group "%M\%S\%p\%P\%5y: %(%g%)%l\n" ,gnus-group-line-format-spec)
 142     (summary-dummy "*  %(:                          :%) %S\n"
 143                    ,gnus-summary-dummy-line-format-spec)
 144     (summary "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n"
 145              ,gnus-summary-line-format-spec))
 146   "Alist of format specs.")
 147
 148 (defvar gnus-default-format-specs gnus-format-specs)
 149
 150 (defvar gnus-article-mode-line-format-spec nil)
 151 (defvar gnus-summary-mode-line-format-spec nil)
 152 (defvar gnus-group-mode-line-format-spec nil)
 153
 154 ;;; Phew.  All that gruft is over with, fortunately.
 155
 156 ;;;###autoload
 157 (defun gnus-update-format (var)
 158   "Update the format specification near point."
 159   (interactive
 160    (list
 161     (save-excursion
 162       (eval-defun nil)
 163       ;; Find the end of the current word.
 164       (re-search-forward "[ \t\n]" nil t)
 165       ;; Search backward.
 166       (when (re-search-backward "\\(gnus-[-a-z]+-line-format\\)" nil t)
 167         (match-string 1)))))
 168   (let* ((type (intern (progn (string-match "gnus-\\([-a-z]+\\)-line" var)
 169                               (match-string 1 var))))
 170          (entry (assq type gnus-format-specs))
 171          value spec)
 172     (when entry
 173       (setq gnus-format-specs (delq entry gnus-format-specs)))
 174     (set
 175      (intern (format "%s-spec" var))
 176      (gnus-parse-format (setq value (symbol-value (intern var)))
 177                         (symbol-value (intern (format "%s-alist" var)))
 178                         (not (string-match "mode" var))))
 179     (setq spec (symbol-value (intern (format "%s-spec" var))))
 180     (push (list type value spec) gnus-format-specs)
 181
 182     (pop-to-buffer "*Gnus Format*")
 183     (erase-buffer)
 184     (lisp-interaction-mode)
 185     (insert (gnus-pp-to-string spec))))
 186
 187 (defun gnus-update-format-specifications (&optional force &rest types)
 188   "Update all (necessary) format specifications.
 189 Return a list of updated types."
 190   ;; Make the indentation array.
 191   ;; See whether all the stored info needs to be flushed.
 192   (when (or force
 193             (not gnus-newsrc-file-version)
 194             (not (equal (gnus-continuum-version)
 195                         (gnus-continuum-version gnus-newsrc-file-version)))
 196             (not (equal emacs-version
 197                         (cdr (assq 'version gnus-format-specs)))))
 198     (setq gnus-format-specs nil))
 199
 200   ;; Go through all the formats and see whether they need updating.
 201   (let (new-format entry type val updated)
 202     (while (setq type (pop types))
 203       ;; Jump to the proper buffer to find out the value of the
 204       ;; variable, if possible.  (It may be buffer-local.)
 205       (save-excursion
 206         (let ((buffer (intern (format "gnus-%s-buffer" type))))
 207           (when (and (boundp buffer)
 208                      (setq val (symbol-value buffer))
 209                      (gnus-buffer-exists-p val))
 210             (set-buffer val))
 211           (setq new-format (symbol-value
 212                             (intern (format "gnus-%s-line-format" type)))))
 213         (setq entry (cdr (assq type gnus-format-specs)))
 214         (if (and (car entry)
 215                  (equal (car entry) new-format))
 216             ;; Use the old format.
 217             (set (intern (format "gnus-%s-line-format-spec" type))
 218                  (cadr entry))
 219           ;; This is a new format.
 220           (setq val
 221                 (if (not (stringp new-format))
 222                     ;; This is a function call or something.
 223                     new-format
 224                   ;; This is a "real" format.
 225                   (gnus-parse-format
 226                    new-format
 227                    (symbol-value
 228                     (intern (format "gnus-%s-line-format-alist" type)))
 229                    (not (string-match "mode$" (symbol-name type))))))
 230           ;; Enter the new format spec into the list.
 231           (if entry
 232               (progn
 233                 (setcar (cdr entry) val)
 234                 (setcar entry new-format))
 235             (push (list type new-format val) gnus-format-specs))
 236           (set (intern (format "gnus-%s-line-format-spec" type)) val)
 237           (push type updated))))
 238
 239     (unless (assq 'version gnus-format-specs)
 240       (push (cons 'version emacs-version) gnus-format-specs))
 241     updated))
 242
 243 (defvar gnus-mouse-face-0 'highlight)
 244 (defvar gnus-mouse-face-1 'highlight)
 245 (defvar gnus-mouse-face-2 'highlight)
 246 (defvar gnus-mouse-face-3 'highlight)
 247 (defvar gnus-mouse-face-4 'highlight)
 248
 249 (defun gnus-mouse-face-function (form type)
 250   `(gnus-put-text-property
 251     (point) (progn ,@form (point))
 252     gnus-mouse-face-prop
 253     ,(if (equal type 0)
 254          'gnus-mouse-face
 255        `(quote ,(symbol-value (intern (format "gnus-mouse-face-%d" type)))))))
 256
 257 (defvar gnus-face-0 'bold)
 258 (defvar gnus-face-1 'italic)
 259 (defvar gnus-face-2 'bold-italic)
 260 (defvar gnus-face-3 'bold)
 261 (defvar gnus-face-4 'bold)
 262
 263 (defun gnus-face-face-function (form type)
 264   `(gnus-add-text-properties
 265     (point) (progn ,@form (point))
 266     '(gnus-face t face ,(symbol-value (intern (format "gnus-face-%d" type))))))
 267
 268 (defun gnus-balloon-face-function (form type)
 269   `(gnus-put-text-property
 270     (point) (progn ,@form (point))
 271     ,(if (fboundp 'balloon-help-mode)
 272          ''balloon-help
 273        ''help-echo)
 274     ,(intern (format "gnus-balloon-face-%d" type))))
 275
 276 (defun gnus-spec-tab (column)
 277   (if (> column 0)
 278       `(insert-char ?  (max (- ,column (current-column)) 0))
 279     (let ((column (abs column)))
 280       `(if (> (current-column) ,column)
 281            (let ((end (point)))
 282              (if (= (move-to-column ,column) ,column)
 283                  (delete-region (point) end)
 284                (delete-region (1- (point)) end)
 285                (insert " ")))
 286          (insert-char ?  (max (- ,column (current-column)) 0))))))
 287
 288 (defun gnus-correct-length (string)
 289   "Return the correct width of STRING."
 290   (let ((length 0))
 291     (mapcar (lambda (char) (incf length (gnus-char-width char))) string)
 292     length))
 293
 294 (defun gnus-correct-substring (string start &optional end)
 295   (let ((wstart 0)
 296         (wend 0)
 297         (wseek 0)
 298         (seek 0)
 299         (length (length string))
 300         (string (concat string "\0")))
 301     ;; Find the start position.
 302     (while (and (< seek length)
 303                 (< wseek start))
 304       (incf wseek (gnus-char-width (aref string seek)))
 305       (incf seek))
 306     (setq wstart seek)
 307     ;; Find the end position.
 308     (while (and (<= seek length)
 309                 (or (not end)
 310                     (<= wseek end)))
 311       (incf wseek (gnus-char-width (aref string seek)))
 312       (incf seek))
 313     (setq wend seek)
 314     (substring string wstart (1- wend))))
 315
 316 (defun gnus-string-width-function ()
 317   (cond
 318    (gnus-use-correct-string-widths
 319     'gnus-correct-length)
 320    ((fboundp 'string-width)
 321     'string-width)
 322    (t
 323     'length)))
 324
 325 (defun gnus-substring-function ()
 326   (cond
 327    (gnus-use-correct-string-widths
 328     'gnus-correct-substring)
 329    ((fboundp 'string-width)
 330     'gnus-correct-substring)
 331    (t
 332     'substring)))
 333
 334 (defun gnus-tilde-max-form (el max-width)
 335   "Return a form that limits EL to MAX-WIDTH."
 336   (let ((max (abs max-width))
 337         (length-fun (gnus-string-width-function))
 338         (substring-fun (gnus-substring-function)))
 339     (if (symbolp el)
 340         `(if (> (,length-fun ,el) ,max)
 341              ,(if (< max-width 0)
 342                   `(,substring-fun ,el (- (,length-fun ,el) ,max))
 343                 `(,substring-fun ,el 0 ,max))
 344            ,el)
 345       `(let ((val (eval ,el)))
 346          (if (> (,length-fun val) ,max)
 347              ,(if (< max-width 0)
 348                   `(,substring-fun val (- (,length-fun val) ,max))
 349                 `(,substring-fun val 0 ,max))
 350            val)))))
 351
 352 (defun gnus-tilde-cut-form (el cut-width)
 353   "Return a form that cuts CUT-WIDTH off of EL."
 354   (let ((cut (abs cut-width))
 355         (length-fun (gnus-string-width-function))
 356         (substring-fun (gnus-substring-function)))
 357     (if (symbolp el)
 358         `(if (> (,length-fun ,el) ,cut)
 359              ,(if (< cut-width 0)
 360                   `(,substring-fun ,el 0 (- (,length-fun ,el) ,cut))
 361                 `(,substring-fun ,el ,cut))
 362            ,el)
 363       `(let ((val (eval ,el)))
 364          (if (> (,length-fun val) ,cut)
 365              ,(if (< cut-width 0)
 366                   `(,substring-fun val 0 (- (,length-fun val) ,cut))
 367                 `(,substring-fun val ,cut))
 368            val)))))
 369
 370 (defun gnus-tilde-ignore-form (el ignore-value)
 371   "Return a form that is blank when EL is IGNORE-VALUE."
 372   (if (symbolp el)
 373       `(if (equal ,el ,ignore-value)
 374            "" ,el)
 375     `(let ((val (eval ,el)))
 376        (if (equal val ,ignore-value)
 377            "" val))))
 378
 379 (defun gnus-pad-form (el pad-width)
 380   "Return a form that pads EL to PAD-WIDTH accounting for multi-column
 381 characters correctly. This is because `format' may pad to columns or to
 382 characters when given a pad value."
 383   (let ((pad (abs pad-width))
 384         (side (< 0 pad-width))
 385         (length-fun (gnus-string-width-function)))
 386     (if (symbolp el)
 387         `(let ((need (- ,pad (,length-fun ,el))))
 388            (if (> need 0)
 389                (concat ,(when side '(make-string need ?\ ))
 390                        ,el
 391                        ,(when (not side) '(make-string need ?\ )))
 392              ,el))
 393       `(let* ((val (eval ,el))
 394               (need (- ,pad (,length-fun val))))
 395          (if (> need 0)
 396              (concat ,(when side '(make-string need ?\ ))
 397                      val
 398                      ,(when (not side) '(make-string need ?\ )))
 399            val)))))
 400
 401 (defun gnus-parse-format (format spec-alist &optional insert)
 402   ;; This function parses the FORMAT string with the help of the
 403   ;; SPEC-ALIST and returns a list that can be eval'ed to return the
 404   ;; string.  If the FORMAT string contains the specifiers %( and %)
 405   ;; the text between them will have the mouse-face text property.
 406   ;; If the FORMAT string contains the specifiers %[ and %], the text between
 407   ;; them will have the balloon-help text property.
 408   (let ((case-fold-search nil))
 409     (if (string-match
 410          "\\`\\(.*\\)%[0-9]?[{(«]\\(.*\\)%[0-9]?[»})]\\(.*\n?\\)\\'\\|%[-0-9]*=\\|%[-0-9]*\\*"
 411          format)
 412         (gnus-parse-complex-format format spec-alist)
 413       ;; This is a simple format.
 414       (gnus-parse-simple-format format spec-alist insert))))
 415
 416 (defun gnus-parse-complex-format (format spec-alist)
 417   (let ((cursor-spec nil))
 418     (save-excursion
 419       (gnus-set-work-buffer)
 420       (insert format)
 421       (goto-char (point-min))
 422       (while (re-search-forward "\"" nil t)
 423         (replace-match "\\\"" nil t))
 424       (goto-char (point-min))
 425       (insert "(\"")
 426       ;; Convert all font specs into font spec lists.
 427       (while (re-search-forward "%\\([0-9]+\\)?\\([«»{}()]\\)" nil t)
 428         (let ((number (if (match-beginning 1)
 429                           (match-string 1) "0"))
 430               (delim (aref (match-string 2) 0)))
 431           (if (or (= delim ?\()
 432                   (= delim ?\{)
 433                   (= delim ?\«))
 434               (replace-match (concat "\"("
 435                                      (cond ((= delim ?\() "mouse")
 436                                            ((= delim ?\{) "face")
 437                                            (t "balloon"))
 438                                      " " number " \"")
 439                              t t)
 440             (replace-match "\")\""))))
 441       (goto-char (point-max))
 442       (insert "\")")
 443       ;; Convert point position commands.
 444       (goto-char (point-min))
 445       (let ((case-fold-search nil))
 446         (while (re-search-forward "%\\([-0-9]+\\)?\\*" nil t)
 447           (replace-match "\"(point)\"" t t)
 448           (setq cursor-spec t)))
 449       ;; Convert TAB commands.
 450       (goto-char (point-min))
 451       (while (re-search-forward "%\\([-0-9]+\\)=" nil t)
 452         (replace-match (format "\"(tab %s)\"" (match-string 1)) t t))
 453       ;; Convert the buffer into the spec.
 454       (goto-char (point-min))
 455       (let ((form (read (current-buffer))))
 456         (if cursor-spec
 457             `(let (gnus-position)
 458                ,@(gnus-complex-form-to-spec form spec-alist)
 459                (if gnus-position
 460                    (gnus-put-text-property gnus-position (1+ gnus-position)
 461                                            'gnus-position t)))
 462           `(progn
 463              ,@(gnus-complex-form-to-spec form spec-alist)))))))
 464
 465 (defun gnus-complex-form-to-spec (form spec-alist)
 466   (delq nil
 467         (mapcar
 468          (lambda (sform)
 469            (cond
 470             ((stringp sform)
 471              (gnus-parse-simple-format sform spec-alist t))
 472             ((eq (car sform) 'point)
 473              '(setq gnus-position (point)))
 474             ((eq (car sform) 'tab)
 475              (gnus-spec-tab (cadr sform)))
 476             (t
 477              (funcall (intern (format "gnus-%s-face-function" (car sform)))
 478                       (gnus-complex-form-to-spec (cddr sform) spec-alist)
 479                       (nth 1 sform)))))
 480          form)))
 481
 482
 483 (defun gnus-xmas-format (fstring &rest args)
 484   "A version of `format' which preserves text properties.
 485
 486 Required for XEmacs, where the built in `format' function strips all text
 487 properties from both the format string and any inserted strings.
 488
 489 Only supports the format sequence %s, and %% for inserting
 490 literal % characters. A pad width and an optional - (to right pad)
 491 are supported for %s."
 492   (let ((re "%%\\|%\\(-\\)?\\([1-9][0-9]*\\)?s")
 493         (n (length args)))
 494     (with-temp-buffer
 495       (insert fstring)
 496       (goto-char (point-min))
 497       (while (re-search-forward re nil t)
 498         (goto-char (match-end 0))
 499         (cond
 500          ((string= (match-string 0) "%%")
 501           (delete-char -1))
 502          (t
 503           (if (null args)
 504               (error 'wrong-number-of-arguments #'my-format n fstring))
 505           (let* ((minlen (string-to-int (or (match-string 2) "")))
 506                  (arg (car args))
 507                  (str (if (stringp arg) arg (format "%s" arg)))
 508                  (lpad (null (match-string 1)))
 509                  (padlen (max 0 (- minlen (length str)))))
 510             (replace-match "")
 511             (if lpad (insert-char ?\  padlen))
 512             (insert str)
 513             (unless lpad (insert-char ?\  padlen))
 514             (setq args (cdr args))))))
 515       (buffer-string))))
 516
 517 (defun gnus-parse-simple-format (format spec-alist &optional insert)
 518   ;; This function parses the FORMAT string with the help of the
 519   ;; SPEC-ALIST and returns a list that can be eval'ed to return a
 520   ;; string.
 521   (let ((max-width 0)
 522         spec flist fstring elem result dontinsert user-defined
 523         type value pad-width spec-beg cut-width ignore-value
 524         tilde-form tilde elem-type extended-spec)
 525     (save-excursion
 526       (gnus-set-work-buffer)
 527       (insert format)
 528       (goto-char (point-min))
 529       (while (re-search-forward "%" nil t)
 530         (setq user-defined nil
 531               spec-beg nil
 532               pad-width nil
 533               max-width nil
 534               cut-width nil
 535               ignore-value nil
 536               tilde-form nil
 537               extended-spec nil)
 538         (setq spec-beg (1- (point)))
 539
 540         ;; Parse this spec fully.
 541         (while
 542             (cond
 543              ((looking-at "\\([-.0-9]+\\)\\(,[-0-9]+\\)?")
 544               (setq pad-width (string-to-number (match-string 1)))
 545               (when (match-beginning 2)
 546                 (setq max-width (string-to-number (buffer-substring
 547                                                    (1+ (match-beginning 2))
 548                                                    (match-end 2)))))
 549               (goto-char (match-end 0)))
 550              ((looking-at "~")
 551               (forward-char 1)
 552               (setq tilde (read (current-buffer))
 553                     type (car tilde)
 554                     value (cadr tilde))
 555               (cond
 556                ((memq type '(pad pad-left))
 557                 (setq pad-width value))
 558                ((eq type 'pad-right)
 559                 (setq pad-width (- value)))
 560                ((memq type '(max-right max))
 561                 (setq max-width value))
 562                ((eq type 'max-left)
 563                 (setq max-width (- value)))
 564                ((memq type '(cut cut-left))
 565                 (setq cut-width value))
 566                ((eq type 'cut-right)
 567                 (setq cut-width (- value)))
 568                ((eq type 'ignore)
 569                 (setq ignore-value
 570                       (if (stringp value) value (format "%s" value))))
 571                ((eq type 'form)
 572                 (setq tilde-form value))
 573                (t
 574                 (error "Unknown tilde type: %s" tilde)))
 575               t)
 576              (t
 577               nil)))
 578         (cond
 579          ;; User-defined spec -- find the spec name.
 580          ((eq (setq spec (char-after)) ?u)
 581           (forward-char 1)
 582           (when (and (eq (setq user-defined (char-after)) ?&)
 583                      (looking-at "&\\([^;]+\\);"))
 584             (setq user-defined (match-string 1))
 585             (goto-char (match-end 1))))
 586          ;; extended spec
 587          ((and (eq spec ?&) (looking-at "&\\([^;]+\\);"))
 588           (setq extended-spec (intern (match-string 1)))
 589           (goto-char (match-end 1))))
 590         (forward-char 1)
 591         (delete-region spec-beg (point))
 592
 593         ;; Now we have all the relevant data on this spec, so
 594         ;; we start doing stuff.
 595         (insert "%")
 596         (if (eq spec ?%)
 597             ;; "%%" just results in a "%".
 598             (insert "%")
 599           (cond
 600            ;; Do tilde forms.
 601            ((eq spec ?@)
 602             (setq elem (list tilde-form ?s)))
 603            ;; Treat user defined format specifiers specially.
 604            (user-defined
 605             (setq elem
 606                   (list
 607                    (list (intern (format
 608                                   (if (stringp user-defined)
 609                                       "gnus-user-format-function-%s"
 610                                     "gnus-user-format-function-%c")
 611                                   user-defined))
 612                          'gnus-tmp-header)
 613                    ?s)))
 614            ;; Find the specification from `spec-alist'.
 615            ((setq elem (cdr (assq (or extended-spec spec) spec-alist))))
 616            (t
 617             (setq elem '("*" ?s))))
 618           (setq elem-type (cadr elem))
 619           ;; Insert the new format elements.
 620           (when (and pad-width
 621                      (not (and (featurep 'xemacs)
 622                                gnus-use-correct-string-widths)))
 623             (insert (number-to-string pad-width)))
 624           ;; Create the form to be evaled.
 625           (if (or max-width cut-width ignore-value
 626                   (and (featurep 'xemacs)
 627                        gnus-use-correct-string-widths))
 628               (progn
 629                 (insert ?s)
 630                 (let ((el (car elem)))
 631                   (cond ((= (cadr elem) ?c)
 632                          (setq el (list 'char-to-string el)))
 633                         ((= (cadr elem) ?d)
 634                          (setq el (list 'int-to-string el))))
 635                   (when ignore-value
 636                     (setq el (gnus-tilde-ignore-form el ignore-value)))
 637                   (when cut-width
 638                     (setq el (gnus-tilde-cut-form el cut-width)))
 639                   (when max-width
 640                     (setq el (gnus-tilde-max-form el max-width)))
 641                   (when pad-width
 642                     (setq el (gnus-pad-form el pad-width)))
 643                   (push el flist)))
 644             (insert elem-type)
 645             (push (car elem) flist))))
 646       (setq fstring (buffer-substring-no-properties (point-min) (point-max))))
 647
 648     ;; Do some postprocessing to increase efficiency.
 649     (setq
 650      result
 651      (cond
 652       ;; Emptiness.
 653       ((string= fstring "")
 654        nil)
 655       ;; Not a format string.
 656       ((not (string-match "%" fstring))
 657        (list fstring))
 658       ;; A format string with just a single string spec.
 659       ((string= fstring "%s")
 660        (list (car flist)))
 661       ;; A single character.
 662       ((string= fstring "%c")
 663        (list (car flist)))
 664       ;; A single number.
 665       ((string= fstring "%d")
 666        (setq dontinsert)
 667        (if insert
 668            (list `(princ ,(car flist)))
 669          (list `(int-to-string ,(car flist)))))
 670       ;; Just lots of chars and strings.
 671       ((string-match "\\`\\(%[cs]\\)+\\'" fstring)
 672        (nreverse flist))
 673       ;; A single string spec at the beginning of the spec.
 674       ((string-match "\\`%[sc][^%]+\\'" fstring)
 675        (list (car flist) (substring fstring 2)))
 676       ;; A single string spec in the middle of the spec.
 677       ((string-match "\\`\\([^%]+\\)%[sc]\\([^%]+\\)\\'" fstring)
 678        (list (match-string 1 fstring) (car flist) (match-string 2 fstring)))
 679       ;; A single string spec in the end of the spec.
 680       ((string-match "\\`\\([^%]+\\)%[sc]\\'" fstring)
 681        (list (match-string 1 fstring) (car flist)))
 682       ;; Only string (and %) specs (XEmacs only!)
 683       ((and (featurep 'xemacs)
 684             gnus-make-format-preserve-properties
 685             (string-match
 686              "\\`\\([^%]*\\(%%\\|%-?\\([1-9][0-9]*\\)?s\\)\\)*[^%]*\\'"
 687              fstring))
 688        (list (cons 'gnus-xmas-format (cons fstring (nreverse flist)))))
 689       ;; A more complex spec.
 690       (t
 691        (list (cons 'format (cons fstring (nreverse flist)))))))
 692
 693     (if insert
 694         (when result
 695           (if dontinsert
 696               result
 697             (cons 'insert result)))
 698       (cond ((stringp result)
 699              result)
 700             ((consp result)
 701              (cons 'concat result))
 702             (t "")))))
 703
 704 (defun gnus-eval-format (format &optional alist props)
 705   "Eval the format variable FORMAT, using ALIST.
 706 If PROPS, insert the result."
 707   (let ((form (gnus-parse-format format alist props)))
 708     (if props
 709         (gnus-add-text-properties (point) (progn (eval form) (point)) props)
 710       (eval form))))
 711
 712 (defun gnus-compile ()
 713   "Byte-compile the user-defined format specs."
 714   (interactive)
 715   (require 'bytecomp)
 716   (let ((entries gnus-format-specs)
 717         (byte-compile-warnings '(unresolved callargs redefine))
 718         entry gnus-tmp-func)
 719     (save-excursion
 720       (gnus-message 7 "Compiling format specs...")
 721
 722       (while entries
 723         (setq entry (pop entries))
 724         (if (memq (car entry) '(gnus-version version))
 725             (setq gnus-format-specs (delq entry gnus-format-specs))
 726           (let ((form (caddr entry)))
 727             (when (and (listp form)
 728                        ;; Under GNU Emacs, it's (byte-code ...)
 729                        (not (eq 'byte-code (car form)))
 730                        ;; Under XEmacs, it's (funcall #<compiled-function ...>)
 731                        (not (and (eq 'funcall (car form))
 732                                  (byte-code-function-p (cadr form)))))
 733               (defalias 'gnus-tmp-func `(lambda () ,form))
 734               (byte-compile 'gnus-tmp-func)
 735               (setcar (cddr entry) (gnus-byte-code 'gnus-tmp-func))))))
 736
 737       (push (cons 'version emacs-version) gnus-format-specs)
 738       ;; Mark the .newsrc.eld file as "dirty".
 739       (gnus-dribble-touch)
 740       (gnus-message 7 "Compiling user specs...done"))))
 741
 742 (defun gnus-set-format (type &optional insertable)
 743   (set (intern (format "gnus-%s-line-format-spec" type))
 744        (gnus-parse-format
 745         (symbol-value (intern (format "gnus-%s-line-format" type)))
 746         (symbol-value (intern (format "gnus-%s-line-format-alist" type)))
 747         insertable)))
 748
 749 (provide 'gnus-spec)
 750
 751 ;; Local Variables:
 752 ;; coding: iso-8859-1
 753 ;; End:
 754
 755 ;;; arch-tag: a4328fa1-1f84-4b09-97ad-4b5767cfd50f
 756 ;;; gnus-spec.el ends here