lisp/gnus/gnus-spec.el

   1 ;;; gnus-spec.el --- format spec functions for Gnus
   2
   3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007 Free Software Foundation, Inc.
   5
   6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   7 ;; Keywords: news
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;;; Code:
  29
  30 (eval-when-compile (require 'cl))
  31 (defvar gnus-newsrc-file-version)
  32
  33 (require 'gnus)
  34
  35 (defcustom gnus-use-correct-string-widths (featurep 'xemacs)
  36   "*If non-nil, use correct functions for dealing with wide characters."
  37   :version "22.1"
  38   :group 'gnus-format
  39   :type 'boolean)
  40
  41 (defcustom gnus-make-format-preserve-properties (featurep 'xemacs)
  42   "*If non-nil, use a replacement `format' function which preserves
  43 text properties. This is only needed on XEmacs, as FSF Emacs does this anyway."
  44   :version "22.1"
  45   :group 'gnus-format
  46   :type 'boolean)
  47
  48 ;;; Internal variables.
  49
  50 (defvar gnus-summary-mark-positions nil)
  51 (defvar gnus-group-mark-positions nil)
  52 (defvar gnus-group-indentation "")
  53
  54 ;; Format specs.  The chunks below are the machine-generated forms
  55 ;; that are to be evaled as the result of the default format strings.
  56 ;; We write them in here to get them byte-compiled.  That way the
  57 ;; default actions will be quite fast, while still retaining the full
  58 ;; flexibility of the user-defined format specs.
  59
  60 ;; First we have lots of dummy defvars to let the compiler know these
  61 ;; are really dynamic variables.
  62
  63 (defvar gnus-tmp-unread)
  64 (defvar gnus-tmp-replied)
  65 (defvar gnus-tmp-score-char)
  66 (defvar gnus-tmp-indentation)
  67 (defvar gnus-tmp-opening-bracket)
  68 (defvar gnus-tmp-lines)
  69 (defvar gnus-tmp-name)
  70 (defvar gnus-tmp-closing-bracket)
  71 (defvar gnus-tmp-subject-or-nil)
  72 (defvar gnus-tmp-subject)
  73 (defvar gnus-tmp-marked)
  74 (defvar gnus-tmp-marked-mark)
  75 (defvar gnus-tmp-subscribed)
  76 (defvar gnus-tmp-process-marked)
  77 (defvar gnus-tmp-number-of-unread)
  78 (defvar gnus-tmp-group-name)
  79 (defvar gnus-tmp-group)
  80 (defvar gnus-tmp-article-number)
  81 (defvar gnus-tmp-unread-and-unselected)
  82 (defvar gnus-tmp-news-method)
  83 (defvar gnus-tmp-news-server)
  84 (defvar gnus-tmp-article-number)
  85 (defvar gnus-mouse-face)
  86 (defvar gnus-mouse-face-prop)
  87 (defvar gnus-tmp-header)
  88 (defvar gnus-tmp-from)
  89
  90 (defun gnus-summary-line-format-spec ()
  91   (insert gnus-tmp-unread gnus-tmp-replied
  92           gnus-tmp-score-char gnus-tmp-indentation)
  93   (gnus-put-text-property
  94    (point)
  95    (progn
  96      (insert
  97       (format "%c%4s: %-23s%c" gnus-tmp-opening-bracket gnus-tmp-lines
  98               (let ((val
  99                      (inline
 100                        (gnus-summary-from-or-to-or-newsgroups
 101                         gnus-tmp-header gnus-tmp-from))))
 102                 (if (> (length val) 23)
 103                     (substring val 0 23)
 104                   val))
 105               gnus-tmp-closing-bracket))
 106      (point))
 107    gnus-mouse-face-prop gnus-mouse-face)
 108   (insert " " gnus-tmp-subject-or-nil "\n"))
 109
 110 (defvar gnus-summary-line-format-spec
 111   (gnus-byte-code 'gnus-summary-line-format-spec))
 112
 113 (defun gnus-summary-dummy-line-format-spec ()
 114   (insert "*  ")
 115   (gnus-put-text-property
 116    (point)
 117    (progn
 118      (insert ":                          :")
 119      (point))
 120    gnus-mouse-face-prop gnus-mouse-face)
 121   (insert " " gnus-tmp-subject "\n"))
 122
 123 (defvar gnus-summary-dummy-line-format-spec
 124   (gnus-byte-code 'gnus-summary-dummy-line-format-spec))
 125
 126 (defun gnus-group-line-format-spec ()
 127   (insert gnus-tmp-marked-mark gnus-tmp-subscribed
 128           gnus-tmp-process-marked
 129           gnus-group-indentation
 130           (format "%5s: " gnus-tmp-number-of-unread))
 131   (gnus-put-text-property
 132    (point)
 133    (progn
 134      (insert gnus-tmp-group "\n")
 135      (1- (point)))
 136    gnus-mouse-face-prop gnus-mouse-face))
 137 (defvar gnus-group-line-format-spec
 138   (gnus-byte-code 'gnus-group-line-format-spec))
 139
 140 (defvar gnus-format-specs
 141   `((version . ,emacs-version)
 142     (gnus-version . ,(gnus-continuum-version))
 143     (group "%M\%S\%p\%P\%5y: %(%g%)%l\n" ,gnus-group-line-format-spec)
 144     (summary-dummy "*  %(:                          :%) %S\n"
 145                    ,gnus-summary-dummy-line-format-spec)
 146     (summary "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n"
 147              ,gnus-summary-line-format-spec))
 148   "Alist of format specs.")
 149
 150 (defvar gnus-default-format-specs gnus-format-specs)
 151
 152 (defvar gnus-article-mode-line-format-spec nil)
 153 (defvar gnus-summary-mode-line-format-spec nil)
 154 (defvar gnus-group-mode-line-format-spec nil)
 155
 156 ;;; Phew.  All that gruft is over with, fortunately.
 157
 158 ;;;###autoload
 159 (defun gnus-update-format (var)
 160   "Update the format specification near point."
 161   (interactive
 162    (list
 163     (save-excursion
 164       (eval-defun nil)
 165       ;; Find the end of the current word.
 166       (re-search-forward "[ \t\n]" nil t)
 167       ;; Search backward.
 168       (when (re-search-backward "\\(gnus-[-a-z]+-line-format\\)" nil t)
 169         (match-string 1)))))
 170   (let* ((type (intern (progn (string-match "gnus-\\([-a-z]+\\)-line" var)
 171                               (match-string 1 var))))
 172          (entry (assq type gnus-format-specs))
 173          value spec)
 174     (when entry
 175       (setq gnus-format-specs (delq entry gnus-format-specs)))
 176     (set
 177      (intern (format "%s-spec" var))
 178      (gnus-parse-format (setq value (symbol-value (intern var)))
 179                         (symbol-value (intern (format "%s-alist" var)))
 180                         (not (string-match "mode" var))))
 181     (setq spec (symbol-value (intern (format "%s-spec" var))))
 182     (push (list type value spec) gnus-format-specs)
 183
 184     (pop-to-buffer "*Gnus Format*")
 185     (erase-buffer)
 186     (lisp-interaction-mode)
 187     (insert (gnus-pp-to-string spec))))
 188
 189 (defun gnus-update-format-specifications (&optional force &rest types)
 190   "Update all (necessary) format specifications.
 191 Return a list of updated types."
 192   ;; Make the indentation array.
 193   ;; See whether all the stored info needs to be flushed.
 194   (when (or force
 195             (not gnus-newsrc-file-version)
 196             (not (equal (gnus-continuum-version)
 197                         (gnus-continuum-version gnus-newsrc-file-version)))
 198             (not (equal emacs-version
 199                         (cdr (assq 'version gnus-format-specs)))))
 200     (setq gnus-format-specs nil))
 201   ;; Flush the group format spec cache if it doesn't support decoded
 202   ;; group names.
 203   (when (memq 'group types)
 204     (let ((spec (assq 'group gnus-format-specs)))
 205       (unless (string-match " gnus-tmp-decoded-group[ )]"
 206                             (gnus-prin1-to-string (nth 2 spec)))
 207         (setq gnus-format-specs (delq spec gnus-format-specs)))))
 208
 209   ;; Go through all the formats and see whether they need updating.
 210   (let (new-format entry type val updated)
 211     (while (setq type (pop types))
 212       ;; Jump to the proper buffer to find out the value of the
 213       ;; variable, if possible.  (It may be buffer-local.)
 214       (save-excursion
 215         (let ((buffer (intern (format "gnus-%s-buffer" type))))
 216           (when (and (boundp buffer)
 217                      (setq val (symbol-value buffer))
 218                      (gnus-buffer-exists-p val))
 219             (set-buffer val))
 220           (setq new-format (symbol-value
 221                             (intern (format "gnus-%s-line-format" type)))))
 222         (setq entry (cdr (assq type gnus-format-specs)))
 223         (if (and (car entry)
 224                  (equal (car entry) new-format))
 225             ;; Use the old format.
 226             (set (intern (format "gnus-%s-line-format-spec" type))
 227                  (cadr entry))
 228           ;; This is a new format.
 229           (setq val
 230                 (if (not (stringp new-format))
 231                     ;; This is a function call or something.
 232                     new-format
 233                   ;; This is a "real" format.
 234                   (gnus-parse-format
 235                    new-format
 236                    (symbol-value
 237                     (intern (format "gnus-%s-line-format-alist" type)))
 238                    (not (string-match "mode$" (symbol-name type))))))
 239           ;; Enter the new format spec into the list.
 240           (if entry
 241               (progn
 242                 (setcar (cdr entry) val)
 243                 (setcar entry new-format))
 244             (push (list type new-format val) gnus-format-specs))
 245           (set (intern (format "gnus-%s-line-format-spec" type)) val)
 246           (push type updated))))
 247
 248     (unless (assq 'version gnus-format-specs)
 249       (push (cons 'version emacs-version) gnus-format-specs))
 250     updated))
 251
 252 (defvar gnus-mouse-face-0 'highlight)
 253 (defvar gnus-mouse-face-1 'highlight)
 254 (defvar gnus-mouse-face-2 'highlight)
 255 (defvar gnus-mouse-face-3 'highlight)
 256 (defvar gnus-mouse-face-4 'highlight)
 257
 258 (defun gnus-mouse-face-function (form type)
 259   `(gnus-put-text-property
 260     (point) (progn ,@form (point))
 261     gnus-mouse-face-prop
 262     ,(if (equal type 0)
 263          'gnus-mouse-face
 264        `(quote ,(symbol-value (intern (format "gnus-mouse-face-%d" type)))))))
 265
 266 (defvar gnus-face-0 'bold)
 267 (defvar gnus-face-1 'italic)
 268 (defvar gnus-face-2 'bold-italic)
 269 (defvar gnus-face-3 'bold)
 270 (defvar gnus-face-4 'bold)
 271
 272 (defun gnus-face-face-function (form type)
 273   `(gnus-add-text-properties
 274     (point) (progn ,@form (point))
 275     '(gnus-face t face ,(symbol-value (intern (format "gnus-face-%d" type))))))
 276
 277 (defun gnus-balloon-face-function (form type)
 278   `(gnus-put-text-property
 279     (point) (progn ,@form (point))
 280     ,(if (fboundp 'balloon-help-mode)
 281          ''balloon-help
 282        ''help-echo)
 283     ,(intern (format "gnus-balloon-face-%d" type))))
 284
 285 (defun gnus-spec-tab (column)
 286   (if (> column 0)
 287       `(insert-char ?  (max (- ,column (current-column)) 0))
 288     (let ((column (abs column)))
 289       `(if (> (current-column) ,column)
 290            (let ((end (point)))
 291              (if (= (move-to-column ,column) ,column)
 292                  (delete-region (point) end)
 293                (delete-region (1- (point)) end)
 294                (insert " ")))
 295          (insert-char ?  (max (- ,column (current-column)) 0))))))
 296
 297 (defun gnus-correct-length (string)
 298   "Return the correct width of STRING."
 299   (let ((length 0))
 300     (mapcar (lambda (char) (incf length (gnus-char-width char))) string)
 301     length))
 302
 303 (defun gnus-correct-substring (string start &optional end)
 304   (let ((wstart 0)
 305         (wend 0)
 306         (wseek 0)
 307         (seek 0)
 308         (length (length string))
 309         (string (concat string "\0")))
 310     ;; Find the start position.
 311     (while (and (< seek length)
 312                 (< wseek start))
 313       (incf wseek (gnus-char-width (aref string seek)))
 314       (incf seek))
 315     (setq wstart seek)
 316     ;; Find the end position.
 317     (while (and (<= seek length)
 318                 (or (not end)
 319                     (<= wseek end)))
 320       (incf wseek (gnus-char-width (aref string seek)))
 321       (incf seek))
 322     (setq wend seek)
 323     (substring string wstart (1- wend))))
 324
 325 (defun gnus-string-width-function ()
 326   (cond
 327    (gnus-use-correct-string-widths
 328     'gnus-correct-length)
 329    ((fboundp 'string-width)
 330     'string-width)
 331    (t
 332     'length)))
 333
 334 (defun gnus-substring-function ()
 335   (cond
 336    (gnus-use-correct-string-widths
 337     'gnus-correct-substring)
 338    ((fboundp 'string-width)
 339     'gnus-correct-substring)
 340    (t
 341     'substring)))
 342
 343 (defun gnus-tilde-max-form (el max-width)
 344   "Return a form that limits EL to MAX-WIDTH."
 345   (let ((max (abs max-width))
 346         (length-fun (gnus-string-width-function))
 347         (substring-fun (gnus-substring-function)))
 348     (if (symbolp el)
 349         `(if (> (,length-fun ,el) ,max)
 350              ,(if (< max-width 0)
 351                   `(,substring-fun ,el (- (,length-fun ,el) ,max))
 352                 `(,substring-fun ,el 0 ,max))
 353            ,el)
 354       `(let ((val (eval ,el)))
 355          (if (> (,length-fun val) ,max)
 356              ,(if (< max-width 0)
 357                   `(,substring-fun val (- (,length-fun val) ,max))
 358                 `(,substring-fun val 0 ,max))
 359            val)))))
 360
 361 (defun gnus-tilde-cut-form (el cut-width)
 362   "Return a form that cuts CUT-WIDTH off of EL."
 363   (let ((cut (abs cut-width))
 364         (length-fun (gnus-string-width-function))
 365         (substring-fun (gnus-substring-function)))
 366     (if (symbolp el)
 367         `(if (> (,length-fun ,el) ,cut)
 368              ,(if (< cut-width 0)
 369                   `(,substring-fun ,el 0 (- (,length-fun ,el) ,cut))
 370                 `(,substring-fun ,el ,cut))
 371            ,el)
 372       `(let ((val (eval ,el)))
 373          (if (> (,length-fun val) ,cut)
 374              ,(if (< cut-width 0)
 375                   `(,substring-fun val 0 (- (,length-fun val) ,cut))
 376                 `(,substring-fun val ,cut))
 377            val)))))
 378
 379 (defun gnus-tilde-ignore-form (el ignore-value)
 380   "Return a form that is blank when EL is IGNORE-VALUE."
 381   (if (symbolp el)
 382       `(if (equal ,el ,ignore-value)
 383            "" ,el)
 384     `(let ((val (eval ,el)))
 385        (if (equal val ,ignore-value)
 386            "" val))))
 387
 388 (defun gnus-pad-form (el pad-width)
 389   "Return a form that pads EL to PAD-WIDTH accounting for multi-column
 390 characters correctly. This is because `format' may pad to columns or to
 391 characters when given a pad value."
 392   (let ((pad (abs pad-width))
 393         (side (< 0 pad-width))
 394         (length-fun (gnus-string-width-function)))
 395     (if (symbolp el)
 396         `(let ((need (- ,pad (,length-fun ,el))))
 397            (if (> need 0)
 398                (concat ,(when side '(make-string need ?\ ))
 399                        ,el
 400                        ,(when (not side) '(make-string need ?\ )))
 401              ,el))
 402       `(let* ((val (eval ,el))
 403               (need (- ,pad (,length-fun val))))
 404          (if (> need 0)
 405              (concat ,(when side '(make-string need ?\ ))
 406                      val
 407                      ,(when (not side) '(make-string need ?\ )))
 408            val)))))
 409
 410 (defun gnus-parse-format (format spec-alist &optional insert)
 411   ;; This function parses the FORMAT string with the help of the
 412   ;; SPEC-ALIST and returns a list that can be eval'ed to return the
 413   ;; string.  If the FORMAT string contains the specifiers %( and %)
 414   ;; the text between them will have the mouse-face text property.
 415   ;; If the FORMAT string contains the specifiers %[ and %], the text between
 416   ;; them will have the balloon-help text property.
 417   (let ((case-fold-search nil))
 418     (if (string-match
 419          "\\`\\(.*\\)%[0-9]?[{(«]\\(.*\\)%[0-9]?[»})]\\(.*\n?\\)\\'\\|%[-0-9]*=\\|%[-0-9]*\\*"
 420          format)
 421         (gnus-parse-complex-format format spec-alist)
 422       ;; This is a simple format.
 423       (gnus-parse-simple-format format spec-alist insert))))
 424
 425 (defun gnus-parse-complex-format (format spec-alist)
 426   (let ((cursor-spec nil))
 427     (save-excursion
 428       (gnus-set-work-buffer)
 429       (insert format)
 430       (goto-char (point-min))
 431       (while (re-search-forward "\"" nil t)
 432         (replace-match "\\\"" nil t))
 433       (goto-char (point-min))
 434       (insert "(\"")
 435       ;; Convert all font specs into font spec lists.
 436       (while (re-search-forward "%\\([0-9]+\\)?\\([«»{}()]\\)" nil t)
 437         (let ((number (if (match-beginning 1)
 438                           (match-string 1) "0"))
 439               (delim (aref (match-string 2) 0)))
 440           (if (or (= delim ?\()
 441                   (= delim ?\{)
 442                   (= delim ?\«))
 443               (replace-match (concat "\"("
 444                                      (cond ((= delim ?\() "mouse")
 445                                            ((= delim ?\{) "face")
 446                                            (t "balloon"))
 447                                      " " number " \"")
 448                              t t)
 449             (replace-match "\")\""))))
 450       (goto-char (point-max))
 451       (insert "\")")
 452       ;; Convert point position commands.
 453       (goto-char (point-min))
 454       (let ((case-fold-search nil))
 455         (while (re-search-forward "%\\([-0-9]+\\)?\\*" nil t)
 456           (replace-match "\"(point)\"" t t)
 457           (setq cursor-spec t)))
 458       ;; Convert TAB commands.
 459       (goto-char (point-min))
 460       (while (re-search-forward "%\\([-0-9]+\\)=" nil t)
 461         (replace-match (format "\"(tab %s)\"" (match-string 1)) t t))
 462       ;; Convert the buffer into the spec.
 463       (goto-char (point-min))
 464       (let ((form (read (current-buffer))))
 465         (if cursor-spec
 466             `(let (gnus-position)
 467                ,@(gnus-complex-form-to-spec form spec-alist)
 468                (if gnus-position
 469                    (gnus-put-text-property gnus-position (1+ gnus-position)
 470                                            'gnus-position t)))
 471           `(progn
 472              ,@(gnus-complex-form-to-spec form spec-alist)))))))
 473
 474 (defun gnus-complex-form-to-spec (form spec-alist)
 475   (delq nil
 476         (mapcar
 477          (lambda (sform)
 478            (cond
 479             ((stringp sform)
 480              (gnus-parse-simple-format sform spec-alist t))
 481             ((eq (car sform) 'point)
 482              '(setq gnus-position (point)))
 483             ((eq (car sform) 'tab)
 484              (gnus-spec-tab (cadr sform)))
 485             (t
 486              (funcall (intern (format "gnus-%s-face-function" (car sform)))
 487                       (gnus-complex-form-to-spec (cddr sform) spec-alist)
 488                       (nth 1 sform)))))
 489          form)))
 490
 491
 492 (defun gnus-xmas-format (fstring &rest args)
 493   "A version of `format' which preserves text properties.
 494
 495 Required for XEmacs, where the built in `format' function strips all text
 496 properties from both the format string and any inserted strings.
 497
 498 Only supports the format sequence %s, and %% for inserting
 499 literal % characters. A pad width and an optional - (to right pad)
 500 are supported for %s."
 501   (let ((re "%%\\|%\\(-\\)?\\([1-9][0-9]*\\)?s")
 502         (n (length args)))
 503     (with-temp-buffer
 504       (insert fstring)
 505       (goto-char (point-min))
 506       (while (re-search-forward re nil t)
 507         (goto-char (match-end 0))
 508         (cond
 509          ((string= (match-string 0) "%%")
 510           (delete-char -1))
 511          (t
 512           (if (null args)
 513               (error 'wrong-number-of-arguments #'my-format n fstring))
 514           (let* ((minlen (string-to-number (or (match-string 2) "")))
 515                  (arg (car args))
 516                  (str (if (stringp arg) arg (format "%s" arg)))
 517                  (lpad (null (match-string 1)))
 518                  (padlen (max 0 (- minlen (length str)))))
 519             (replace-match "")
 520             (if lpad (insert-char ?\  padlen))
 521             (insert str)
 522             (unless lpad (insert-char ?\  padlen))
 523             (setq args (cdr args))))))
 524       (buffer-string))))
 525
 526 (defun gnus-parse-simple-format (format spec-alist &optional insert)
 527   ;; This function parses the FORMAT string with the help of the
 528   ;; SPEC-ALIST and returns a list that can be eval'ed to return a
 529   ;; string.
 530   (let ((max-width 0)
 531         spec flist fstring elem result dontinsert user-defined
 532         type value pad-width spec-beg cut-width ignore-value
 533         tilde-form tilde elem-type extended-spec)
 534     (save-excursion
 535       (gnus-set-work-buffer)
 536       (insert format)
 537       (goto-char (point-min))
 538       (while (re-search-forward "%" nil t)
 539         (setq user-defined nil
 540               spec-beg nil
 541               pad-width nil
 542               max-width nil
 543               cut-width nil
 544               ignore-value nil
 545               tilde-form nil
 546               extended-spec nil)
 547         (setq spec-beg (1- (point)))
 548
 549         ;; Parse this spec fully.
 550         (while
 551             (cond
 552              ((looking-at "\\([-.0-9]+\\)\\(,[-0-9]+\\)?")
 553               (setq pad-width (string-to-number (match-string 1)))
 554               (when (match-beginning 2)
 555                 (setq max-width (string-to-number (buffer-substring
 556                                                    (1+ (match-beginning 2))
 557                                                    (match-end 2)))))
 558               (goto-char (match-end 0)))
 559              ((looking-at "~")
 560               (forward-char 1)
 561               (setq tilde (read (current-buffer))
 562                     type (car tilde)
 563                     value (cadr tilde))
 564               (cond
 565                ((memq type '(pad pad-left))
 566                 (setq pad-width value))
 567                ((eq type 'pad-right)
 568                 (setq pad-width (- value)))
 569                ((memq type '(max-right max))
 570                 (setq max-width value))
 571                ((eq type 'max-left)
 572                 (setq max-width (- value)))
 573                ((memq type '(cut cut-left))
 574                 (setq cut-width value))
 575                ((eq type 'cut-right)
 576                 (setq cut-width (- value)))
 577                ((eq type 'ignore)
 578                 (setq ignore-value
 579                       (if (stringp value) value (format "%s" value))))
 580                ((eq type 'form)
 581                 (setq tilde-form value))
 582                (t
 583                 (error "Unknown tilde type: %s" tilde)))
 584               t)
 585              (t
 586               nil)))
 587         (cond
 588          ;; User-defined spec -- find the spec name.
 589          ((eq (setq spec (char-after)) ?u)
 590           (forward-char 1)
 591           (when (and (eq (setq user-defined (char-after)) ?&)
 592                      (looking-at "&\\([^;]+\\);"))
 593             (setq user-defined (match-string 1))
 594             (goto-char (match-end 1))))
 595          ;; extended spec
 596          ((and (eq spec ?&) (looking-at "&\\([^;]+\\);"))
 597           (setq extended-spec (intern (match-string 1)))
 598           (goto-char (match-end 1))))
 599         (forward-char 1)
 600         (delete-region spec-beg (point))
 601
 602         ;; Now we have all the relevant data on this spec, so
 603         ;; we start doing stuff.
 604         (insert "%")
 605         (if (eq spec ?%)
 606             ;; "%%" just results in a "%".
 607             (insert "%")
 608           (cond
 609            ;; Do tilde forms.
 610            ((eq spec ?@)
 611             (setq elem (list tilde-form ?s)))
 612            ;; Treat user defined format specifiers specially.
 613            (user-defined
 614             (setq elem
 615                   (list
 616                    (list (intern (format
 617                                   (if (stringp user-defined)
 618                                       "gnus-user-format-function-%s"
 619                                     "gnus-user-format-function-%c")
 620                                   user-defined))
 621                          'gnus-tmp-header)
 622                    ?s)))
 623            ;; Find the specification from `spec-alist'.
 624            ((setq elem (cdr (assq (or extended-spec spec) spec-alist))))
 625            (t
 626             (setq elem '("*" ?s))))
 627           (setq elem-type (cadr elem))
 628           ;; Insert the new format elements.
 629           (when (and pad-width
 630                      (not (and (featurep 'xemacs)
 631                                gnus-use-correct-string-widths)))
 632             (insert (number-to-string pad-width)))
 633           ;; Create the form to be evaled.
 634           (if (or max-width cut-width ignore-value
 635                   (and (featurep 'xemacs)
 636                        gnus-use-correct-string-widths))
 637               (progn
 638                 (insert ?s)
 639                 (let ((el (car elem)))
 640                   (cond ((= (cadr elem) ?c)
 641                          (setq el (list 'char-to-string el)))
 642                         ((= (cadr elem) ?d)
 643                          (setq el (list 'int-to-string el))))
 644                   (when ignore-value
 645                     (setq el (gnus-tilde-ignore-form el ignore-value)))
 646                   (when cut-width
 647                     (setq el (gnus-tilde-cut-form el cut-width)))
 648                   (when max-width
 649                     (setq el (gnus-tilde-max-form el max-width)))
 650                   (when pad-width
 651                     (setq el (gnus-pad-form el pad-width)))
 652                   (push el flist)))
 653             (insert elem-type)
 654             (push (car elem) flist))))
 655       (setq fstring (buffer-substring-no-properties (point-min) (point-max))))
 656
 657     ;; Do some postprocessing to increase efficiency.
 658     (setq
 659      result
 660      (cond
 661       ;; Emptiness.
 662       ((string= fstring "")
 663        nil)
 664       ;; Not a format string.
 665       ((not (string-match "%" fstring))
 666        (list fstring))
 667       ;; A format string with just a single string spec.
 668       ((string= fstring "%s")
 669        (list (car flist)))
 670       ;; A single character.
 671       ((string= fstring "%c")
 672        (list (car flist)))
 673       ;; A single number.
 674       ((string= fstring "%d")
 675        (setq dontinsert)
 676        (if insert
 677            (list `(princ ,(car flist)))
 678          (list `(int-to-string ,(car flist)))))
 679       ;; Just lots of chars and strings.
 680       ((string-match "\\`\\(%[cs]\\)+\\'" fstring)
 681        (nreverse flist))
 682       ;; A single string spec at the beginning of the spec.
 683       ((string-match "\\`%[sc][^%]+\\'" fstring)
 684        (list (car flist) (substring fstring 2)))
 685       ;; A single string spec in the middle of the spec.
 686       ((string-match "\\`\\([^%]+\\)%[sc]\\([^%]+\\)\\'" fstring)
 687        (list (match-string 1 fstring) (car flist) (match-string 2 fstring)))
 688       ;; A single string spec in the end of the spec.
 689       ((string-match "\\`\\([^%]+\\)%[sc]\\'" fstring)
 690        (list (match-string 1 fstring) (car flist)))
 691       ;; Only string (and %) specs (XEmacs only!)
 692       ((and (featurep 'xemacs)
 693             gnus-make-format-preserve-properties
 694             (string-match
 695              "\\`\\([^%]*\\(%%\\|%-?\\([1-9][0-9]*\\)?s\\)\\)*[^%]*\\'"
 696              fstring))
 697        (list (cons 'gnus-xmas-format (cons fstring (nreverse flist)))))
 698       ;; A more complex spec.
 699       (t
 700        (list (cons 'format (cons fstring (nreverse flist)))))))
 701
 702     (if insert
 703         (when result
 704           (if dontinsert
 705               result
 706             (cons 'insert result)))
 707       (cond ((stringp result)
 708              result)
 709             ((consp result)
 710              (cons 'concat result))
 711             (t "")))))
 712
 713 (defun gnus-eval-format (format &optional alist props)
 714   "Eval the format variable FORMAT, using ALIST.
 715 If PROPS, insert the result."
 716   (let ((form (gnus-parse-format format alist props)))
 717     (if props
 718         (gnus-add-text-properties (point) (progn (eval form) (point)) props)
 719       (eval form))))
 720
 721 (defun gnus-compile ()
 722   "Byte-compile the user-defined format specs."
 723   (interactive)
 724   (require 'bytecomp)
 725   (let ((entries gnus-format-specs)
 726         (byte-compile-warnings '(unresolved callargs redefine))
 727         entry gnus-tmp-func)
 728     (save-excursion
 729       (gnus-message 7 "Compiling format specs...")
 730
 731       (while entries
 732         (setq entry (pop entries))
 733         (if (memq (car entry) '(gnus-version version))
 734             (setq gnus-format-specs (delq entry gnus-format-specs))
 735           (let ((form (caddr entry)))
 736             (when (and (listp form)
 737                        ;; Under GNU Emacs, it's (byte-code ...)
 738                        (not (eq 'byte-code (car form)))
 739                        ;; Under XEmacs, it's (funcall #<compiled-function ...>)
 740                        (not (and (eq 'funcall (car form))
 741                                  (byte-code-function-p (cadr form)))))
 742               (defalias 'gnus-tmp-func `(lambda () ,form))
 743               (byte-compile 'gnus-tmp-func)
 744               (setcar (cddr entry) (gnus-byte-code 'gnus-tmp-func))))))
 745
 746       (push (cons 'version emacs-version) gnus-format-specs)
 747       ;; Mark the .newsrc.eld file as "dirty".
 748       (gnus-dribble-touch)
 749       (gnus-message 7 "Compiling user specs...done"))))
 750
 751 (defun gnus-set-format (type &optional insertable)
 752   (set (intern (format "gnus-%s-line-format-spec" type))
 753        (gnus-parse-format
 754         (symbol-value (intern (format "gnus-%s-line-format" type)))
 755         (symbol-value (intern (format "gnus-%s-line-format-alist" type)))
 756         insertable)))
 757
 758 (provide 'gnus-spec)
 759
 760 ;; Local Variables:
 761 ;; coding: iso-8859-1
 762 ;; End:
 763
 764 ;;; arch-tag: a4328fa1-1f84-4b09-97ad-4b5767cfd50f
 765 ;;; gnus-spec.el ends here