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, 2008, 2009, 2010 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 3 of the License, or
  14 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;;; Code:
  27
  28 ;; For Emacs < 22.2.
  29 (eval-and-compile
  30   (unless (fboundp 'declare-function) (defmacro declare-function (&rest r))))
  31 (eval-when-compile (require 'cl))
  32 (defvar gnus-newsrc-file-version)
  33
  34 (require 'gnus)
  35
  36 (defcustom gnus-use-correct-string-widths (featurep 'xemacs)
  37   "*If non-nil, use correct functions for dealing with wide characters."
  38   :version "22.1"
  39   :group 'gnus-format
  40   :type 'boolean)
  41
  42 (defcustom gnus-make-format-preserve-properties (featurep 'xemacs)
  43   "*If non-nil, use a replacement `format' function which preserves
  44 text properties. This is only needed on XEmacs, as Emacs does this anyway."
  45   :version "22.1"
  46   :group 'gnus-format
  47   :type 'boolean)
  48
  49 ;;; Internal variables.
  50
  51 (defvar gnus-summary-mark-positions nil)
  52 (defvar gnus-group-mark-positions nil)
  53 (defvar gnus-group-indentation "")
  54
  55 ;; Format specs.  The chunks below are the machine-generated forms
  56 ;; that are to be evaled as the result of the default format strings.
  57 ;; We write them in here to get them byte-compiled.  That way the
  58 ;; default actions will be quite fast, while still retaining the full
  59 ;; flexibility of the user-defined format specs.
  60
  61 ;; First we have lots of dummy defvars to let the compiler know these
  62 ;; are really dynamic variables.
  63
  64 (defvar gnus-tmp-unread)
  65 (defvar gnus-tmp-replied)
  66 (defvar gnus-tmp-score-char)
  67 (defvar gnus-tmp-indentation)
  68 (defvar gnus-tmp-opening-bracket)
  69 (defvar gnus-tmp-lines)
  70 (defvar gnus-tmp-name)
  71 (defvar gnus-tmp-closing-bracket)
  72 (defvar gnus-tmp-subject-or-nil)
  73 (defvar gnus-tmp-subject)
  74 (defvar gnus-tmp-marked)
  75 (defvar gnus-tmp-marked-mark)
  76 (defvar gnus-tmp-subscribed)
  77 (defvar gnus-tmp-process-marked)
  78 (defvar gnus-tmp-number-of-unread)
  79 (defvar gnus-tmp-group-name)
  80 (defvar gnus-tmp-group)
  81 (defvar gnus-tmp-article-number)
  82 (defvar gnus-tmp-unread-and-unselected)
  83 (defvar gnus-tmp-news-method)
  84 (defvar gnus-tmp-news-server)
  85 (defvar gnus-tmp-article-number)
  86 (defvar gnus-mouse-face)
  87 (defvar gnus-mouse-face-prop)
  88 (defvar gnus-tmp-header)
  89 (defvar gnus-tmp-from)
  90
  91 (declare-function gnus-summary-from-or-to-or-newsgroups "gnus-sum"
  92                   (header gnus-tmp-from))
  93
  94 (defun gnus-summary-line-format-spec ()
  95   (insert gnus-tmp-unread gnus-tmp-replied
  96           gnus-tmp-score-char gnus-tmp-indentation)
  97   (gnus-put-text-property
  98    (point)
  99    (progn
 100      (insert
 101       (format "%c%4s: %-23s%c" gnus-tmp-opening-bracket gnus-tmp-lines
 102               (let ((val
 103                      (inline
 104                        (gnus-summary-from-or-to-or-newsgroups
 105                         gnus-tmp-header gnus-tmp-from))))
 106                 (if (> (length val) 23)
 107                     (substring val 0 23)
 108                   val))
 109               gnus-tmp-closing-bracket))
 110      (point))
 111    gnus-mouse-face-prop gnus-mouse-face)
 112   (insert " " gnus-tmp-subject-or-nil "\n"))
 113
 114 (defvar gnus-summary-line-format-spec
 115   (gnus-byte-code 'gnus-summary-line-format-spec))
 116
 117 (defun gnus-summary-dummy-line-format-spec ()
 118   (insert "*  ")
 119   (gnus-put-text-property
 120    (point)
 121    (progn
 122      (insert ":                          :")
 123      (point))
 124    gnus-mouse-face-prop gnus-mouse-face)
 125   (insert " " gnus-tmp-subject "\n"))
 126
 127 (defvar gnus-summary-dummy-line-format-spec
 128   (gnus-byte-code 'gnus-summary-dummy-line-format-spec))
 129
 130 (defun gnus-group-line-format-spec ()
 131   (insert gnus-tmp-marked-mark gnus-tmp-subscribed
 132           gnus-tmp-process-marked
 133           gnus-group-indentation
 134           (format "%5s: " gnus-tmp-number-of-unread))
 135   (gnus-put-text-property
 136    (point)
 137    (progn
 138      (insert gnus-tmp-group "\n")
 139      (1- (point)))
 140    gnus-mouse-face-prop gnus-mouse-face))
 141 (defvar gnus-group-line-format-spec
 142   (gnus-byte-code 'gnus-group-line-format-spec))
 143
 144 (defvar gnus-format-specs
 145   `((version . ,emacs-version)
 146     (gnus-version . ,(gnus-continuum-version))
 147     (group "%M\%S\%p\%P\%5y: %(%g%)\n" ,gnus-group-line-format-spec)
 148     (summary-dummy "*  %(:                          :%) %S\n"
 149                    ,gnus-summary-dummy-line-format-spec)
 150     (summary "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n"
 151              ,gnus-summary-line-format-spec))
 152   "Alist of format specs.")
 153
 154 (defvar gnus-default-format-specs gnus-format-specs)
 155
 156 (defvar gnus-article-mode-line-format-spec nil)
 157 (defvar gnus-summary-mode-line-format-spec nil)
 158 (defvar gnus-group-mode-line-format-spec nil)
 159
 160 ;;; Phew.  All that gruft is over with, fortunately.
 161
 162 ;;;###autoload
 163 (defun gnus-update-format (var)
 164   "Update the format specification near point."
 165   (interactive
 166    (list
 167     (save-excursion
 168       (eval-defun nil)
 169       ;; Find the end of the current word.
 170       (re-search-forward "[ \t\n]" nil t)
 171       ;; Search backward.
 172       (when (re-search-backward "\\(gnus-[-a-z]+-line-format\\)" nil t)
 173         (match-string 1)))))
 174   (let* ((type (intern (progn (string-match "gnus-\\([-a-z]+\\)-line" var)
 175                               (match-string 1 var))))
 176          (entry (assq type gnus-format-specs))
 177          value spec)
 178     (when entry
 179       (setq gnus-format-specs (delq entry gnus-format-specs)))
 180     (set
 181      (intern (format "%s-spec" var))
 182      (gnus-parse-format (setq value (symbol-value (intern var)))
 183                         (symbol-value (intern (format "%s-alist" var)))
 184                         (not (string-match "mode" var))))
 185     (setq spec (symbol-value (intern (format "%s-spec" var))))
 186     (push (list type value spec) gnus-format-specs)
 187
 188     (pop-to-buffer "*Gnus Format*")
 189     (erase-buffer)
 190     (lisp-interaction-mode)
 191     (insert (gnus-pp-to-string spec))))
 192
 193 (defun gnus-update-format-specifications (&optional force &rest types)
 194   "Update all (necessary) format specifications.
 195 Return a list of updated types."
 196   ;; Make the indentation array.
 197   ;; See whether all the stored info needs to be flushed.
 198   (when (or force
 199             (not gnus-newsrc-file-version)
 200             (not (equal (gnus-continuum-version)
 201                         (gnus-continuum-version gnus-newsrc-file-version)))
 202             (not (equal emacs-version
 203                         (cdr (assq 'version gnus-format-specs)))))
 204     (setq gnus-format-specs nil))
 205   ;; Flush the group format spec cache if there's the grouplens stuff
 206   ;; or it doesn't support decoded group names.
 207   (when (memq 'group types)
 208     (let* ((spec (assq 'group gnus-format-specs))
 209            (sspec (gnus-prin1-to-string (nth 2 spec))))
 210       (when (or (string-match " gnus-tmp-grouplens[ )]" sspec)
 211                 (not (string-match " gnus-tmp-decoded-group[ )]" sspec)))
 212         (setq gnus-format-specs (delq spec gnus-format-specs)))))
 213
 214   ;; Go through all the formats and see whether they need updating.
 215   (let (new-format entry type val updated)
 216     (while (setq type (pop types))
 217       ;; Jump to the proper buffer to find out the value of the
 218       ;; variable, if possible.  (It may be buffer-local.)
 219       (save-excursion
 220         (let ((buffer (intern (format "gnus-%s-buffer" type))))
 221           (when (and (boundp buffer)
 222                      (setq val (symbol-value buffer))
 223                      (gnus-buffer-exists-p val))
 224             (set-buffer val))
 225           (setq new-format (symbol-value
 226                             (intern (format "gnus-%s-line-format" type)))))
 227         (setq entry (cdr (assq type gnus-format-specs)))
 228         (if (and (car entry)
 229                  (equal (car entry) new-format))
 230             ;; Use the old format.
 231             (set (intern (format "gnus-%s-line-format-spec" type))
 232                  (cadr entry))
 233           ;; This is a new format.
 234           (setq val
 235                 (if (not (stringp new-format))
 236                     ;; This is a function call or something.
 237                     new-format
 238                   ;; This is a "real" format.
 239                   (gnus-parse-format
 240                    new-format
 241                    (symbol-value
 242                     (intern (format "gnus-%s-line-format-alist" type)))
 243                    (not (string-match "mode$" (symbol-name type))))))
 244           ;; Enter the new format spec into the list.
 245           (if entry
 246               (progn
 247                 (setcar (cdr entry) val)
 248                 (setcar entry new-format))
 249             (push (list type new-format val) gnus-format-specs))
 250           (set (intern (format "gnus-%s-line-format-spec" type)) val)
 251           (push type updated))))
 252
 253     (unless (assq 'version gnus-format-specs)
 254       (push (cons 'version emacs-version) gnus-format-specs))
 255     updated))
 256
 257 (defvar gnus-mouse-face-0 'highlight)
 258 (defvar gnus-mouse-face-1 'highlight)
 259 (defvar gnus-mouse-face-2 'highlight)
 260 (defvar gnus-mouse-face-3 'highlight)
 261 (defvar gnus-mouse-face-4 'highlight)
 262
 263 (defun gnus-mouse-face-function (form type)
 264   `(gnus-put-text-property
 265     (point) (progn ,@form (point))
 266     gnus-mouse-face-prop
 267     ,(if (equal type 0)
 268          'gnus-mouse-face
 269        `(quote ,(symbol-value (intern (format "gnus-mouse-face-%d" type)))))))
 270
 271 (defvar gnus-face-0 'bold)
 272 (defvar gnus-face-1 'italic)
 273 (defvar gnus-face-2 'bold-italic)
 274 (defvar gnus-face-3 'bold)
 275 (defvar gnus-face-4 'bold)
 276
 277 (defun gnus-face-face-function (form type)
 278   `(gnus-add-text-properties
 279     (point) (progn ,@form (point))
 280     '(gnus-face t face ,(symbol-value (intern (format "gnus-face-%d" type))))))
 281
 282 (defun gnus-balloon-face-function (form type)
 283   `(gnus-put-text-property
 284     (point) (progn ,@form (point))
 285     ,(if (fboundp 'balloon-help-mode)
 286          ''balloon-help
 287        ''help-echo)
 288     ,(intern (format "gnus-balloon-face-%d" type))))
 289
 290 (defun gnus-spec-tab (column)
 291   (if (> column 0)
 292       `(insert-char ?  (max (- ,column (current-column)) 0))
 293     (let ((column (abs column)))
 294       `(if (> (current-column) ,column)
 295            (let ((end (point)))
 296              (if (= (move-to-column ,column) ,column)
 297                  (delete-region (point) end)
 298                (delete-region (1- (point)) end)
 299                (insert " ")))
 300          (insert-char ?  (max (- ,column (current-column)) 0))))))
 301
 302 (defun gnus-correct-length (string)
 303   "Return the correct width of STRING."
 304   (apply #'+ (mapcar #'char-width string)))
 305
 306 (defun gnus-correct-substring (string start &optional end)
 307   (let ((wstart 0)
 308         (wend 0)
 309         (wseek 0)
 310         (seek 0)
 311         (length (length string))
 312         (string (concat string "\0")))
 313     ;; Find the start position.
 314     (while (and (< seek length)
 315                 (< wseek start))
 316       (incf wseek (char-width (aref string seek)))
 317       (incf seek))
 318     (setq wstart seek)
 319     ;; Find the end position.
 320     (while (and (<= seek length)
 321                 (or (not end)
 322                     (<= wseek end)))
 323       (incf wseek (char-width (aref string seek)))
 324       (incf seek))
 325     (setq wend seek)
 326     (substring string wstart (1- wend))))
 327
 328 (defun gnus-string-width-function ()
 329   (cond
 330    (gnus-use-correct-string-widths
 331     'gnus-correct-length)
 332    ((fboundp 'string-width)
 333     'string-width)
 334    (t
 335     'length)))
 336
 337 (defun gnus-substring-function ()
 338   (cond
 339    (gnus-use-correct-string-widths
 340     'gnus-correct-substring)
 341    ((fboundp 'string-width)
 342     'gnus-correct-substring)
 343    (t
 344     'substring)))
 345
 346 (defun gnus-tilde-max-form (el max-width)
 347   "Return a form that limits EL to MAX-WIDTH."
 348   (let ((max (abs max-width))
 349         (length-fun (gnus-string-width-function))
 350         (substring-fun (gnus-substring-function)))
 351     (if (symbolp el)
 352         `(if (> (,length-fun ,el) ,max)
 353              ,(if (< max-width 0)
 354                   `(,substring-fun ,el (- (,length-fun ,el) ,max))
 355                 `(,substring-fun ,el 0 ,max))
 356            ,el)
 357       `(let ((val (eval ,el)))
 358          (if (> (,length-fun val) ,max)
 359              ,(if (< max-width 0)
 360                   `(,substring-fun val (- (,length-fun val) ,max))
 361                 `(,substring-fun val 0 ,max))
 362            val)))))
 363
 364 (defun gnus-tilde-cut-form (el cut-width)
 365   "Return a form that cuts CUT-WIDTH off of EL."
 366   (let ((cut (abs cut-width))
 367         (length-fun (gnus-string-width-function))
 368         (substring-fun (gnus-substring-function)))
 369     (if (symbolp el)
 370         `(if (> (,length-fun ,el) ,cut)
 371              ,(if (< cut-width 0)
 372                   `(,substring-fun ,el 0 (- (,length-fun ,el) ,cut))
 373                 `(,substring-fun ,el ,cut))
 374            ,el)
 375       `(let ((val (eval ,el)))
 376          (if (> (,length-fun val) ,cut)
 377              ,(if (< cut-width 0)
 378                   `(,substring-fun val 0 (- (,length-fun val) ,cut))
 379                 `(,substring-fun val ,cut))
 380            val)))))
 381
 382 (defun gnus-tilde-ignore-form (el ignore-value)
 383   "Return a form that is blank when EL is IGNORE-VALUE."
 384   (if (symbolp el)
 385       `(if (equal ,el ,ignore-value)
 386            "" ,el)
 387     `(let ((val (eval ,el)))
 388        (if (equal val ,ignore-value)
 389            "" val))))
 390
 391 (defun gnus-pad-form (el pad-width)
 392   "Return a form that pads EL to PAD-WIDTH accounting for multi-column
 393 characters correctly. This is because `format' may pad to columns or to
 394 characters when given a pad value."
 395   (let ((pad (abs pad-width))
 396         (side (< 0 pad-width))
 397         (length-fun (gnus-string-width-function)))
 398     (if (symbolp el)
 399         `(let ((need (- ,pad (,length-fun ,el))))
 400            (if (> need 0)
 401                (concat ,(when side '(make-string need ?\ ))
 402                        ,el
 403                        ,(when (not side) '(make-string need ?\ )))
 404              ,el))
 405       `(let* ((val (eval ,el))
 406               (need (- ,pad (,length-fun val))))
 407          (if (> need 0)
 408              (concat ,(when side '(make-string need ?\ ))
 409                      val
 410                      ,(when (not side) '(make-string need ?\ )))
 411            val)))))
 412
 413 (defun gnus-parse-format (format spec-alist &optional insert)
 414   ;; This function parses the FORMAT string with the help of the
 415   ;; SPEC-ALIST and returns a list that can be eval'ed to return the
 416   ;; string.  If the FORMAT string contains the specifiers %( and %)
 417   ;; the text between them will have the mouse-face text property.
 418   ;; If the FORMAT string contains the specifiers %[ and %], the text between
 419   ;; them will have the balloon-help text property.
 420   (let ((case-fold-search nil))
 421     (if (string-match
 422          "\\`\\(.*\\)%[0-9]?[{(«]\\(.*\\)%[0-9]?[»})]\\(.*\n?\\)\\'\\|%[-0-9]*=\\|%[-0-9]*\\*"
 423          format)
 424         (gnus-parse-complex-format format spec-alist)
 425       ;; This is a simple format.
 426       (gnus-parse-simple-format format spec-alist insert))))
 427
 428 (defun gnus-parse-complex-format (format spec-alist)
 429   (let ((cursor-spec nil))
 430     (save-excursion
 431       (gnus-set-work-buffer)
 432       (insert format)
 433       (goto-char (point-min))
 434       (while (re-search-forward "\"" nil t)
 435         (replace-match "\\\"" nil t))
 436       (goto-char (point-min))
 437       (insert "(\"")
 438       ;; Convert all font specs into font spec lists.
 439       (while (re-search-forward "%\\([0-9]+\\)?\\([«»{}()]\\)" nil t)
 440         (let ((number (if (match-beginning 1)
 441                           (match-string 1) "0"))
 442               (delim (aref (match-string 2) 0)))
 443           (if (or (= delim ?\()
 444                   (= delim ?\{)
 445                   (= delim ?\«))
 446               (replace-match (concat "\"("
 447                                      (cond ((= delim ?\() "mouse")
 448                                            ((= delim ?\{) "face")
 449                                            (t "balloon"))
 450                                      " " number " \"")
 451                              t t)
 452             (replace-match "\")\""))))
 453       (goto-char (point-max))
 454       (insert "\")")
 455       ;; Convert point position commands.
 456       (goto-char (point-min))
 457       (let ((case-fold-search nil))
 458         (while (re-search-forward "%\\([-0-9]+\\)?\\*" nil t)
 459           (replace-match "\"(point)\"" t t)
 460           (setq cursor-spec t)))
 461       ;; Convert TAB commands.
 462       (goto-char (point-min))
 463       (while (re-search-forward "%\\([-0-9]+\\)=" nil t)
 464         (replace-match (format "\"(tab %s)\"" (match-string 1)) t t))
 465       ;; Convert the buffer into the spec.
 466       (goto-char (point-min))
 467       (let ((form (read (current-buffer))))
 468         (if cursor-spec
 469             `(let (gnus-position)
 470                ,@(gnus-complex-form-to-spec form spec-alist)
 471                (if gnus-position
 472                    (gnus-put-text-property gnus-position (1+ gnus-position)
 473                                            'gnus-position t)))
 474           `(progn
 475              ,@(gnus-complex-form-to-spec form spec-alist)))))))
 476
 477 (defun gnus-complex-form-to-spec (form spec-alist)
 478   (delq nil
 479         (mapcar
 480          (lambda (sform)
 481            (cond
 482             ((stringp sform)
 483              (gnus-parse-simple-format sform spec-alist t))
 484             ((eq (car sform) 'point)
 485              '(setq gnus-position (point)))
 486             ((eq (car sform) 'tab)
 487              (gnus-spec-tab (cadr sform)))
 488             (t
 489              (funcall (intern (format "gnus-%s-face-function" (car sform)))
 490                       (gnus-complex-form-to-spec (cddr sform) spec-alist)
 491                       (nth 1 sform)))))
 492          form)))
 493
 494
 495 (defun gnus-xmas-format (fstring &rest args)
 496   "A version of `format' which preserves text properties.
 497
 498 Required for XEmacs, where the built in `format' function strips all text
 499 properties from both the format string and any inserted strings.
 500
 501 Only supports the format sequence %s, and %% for inserting
 502 literal % characters. A pad width and an optional - (to right pad)
 503 are supported for %s."
 504   (let ((re "%%\\|%\\(-\\)?\\([1-9][0-9]*\\)?s")
 505         (n (length args)))
 506     (with-temp-buffer
 507       (insert fstring)
 508       (goto-char (point-min))
 509       (while (re-search-forward re nil t)
 510         (goto-char (match-end 0))
 511         (cond
 512          ((string= (match-string 0) "%%")
 513           (delete-char -1))
 514          (t
 515           (if (null args)
 516               (error 'wrong-number-of-arguments #'my-format n fstring))
 517           (let* ((minlen (string-to-number (or (match-string 2) "")))
 518                  (arg (car args))
 519                  (str (if (stringp arg) arg (format "%s" arg)))
 520                  (lpad (null (match-string 1)))
 521                  (padlen (max 0 (- minlen (length str)))))
 522             (replace-match "")
 523             (if lpad (insert-char ?\  padlen))
 524             (insert str)
 525             (unless lpad (insert-char ?\  padlen))
 526             (setq args (cdr args))))))
 527       (buffer-string))))
 528
 529 (defun gnus-parse-simple-format (format spec-alist &optional insert)
 530   ;; This function parses the FORMAT string with the help of the
 531   ;; SPEC-ALIST and returns a list that can be eval'ed to return a
 532   ;; string.
 533   (let ((max-width 0)
 534         spec flist fstring elem result dontinsert user-defined
 535         type value pad-width spec-beg cut-width ignore-value
 536         tilde-form tilde elem-type extended-spec)
 537     (save-excursion
 538       (gnus-set-work-buffer)
 539       (insert format)
 540       (goto-char (point-min))
 541       (while (re-search-forward "%" nil t)
 542         (setq user-defined nil
 543               spec-beg nil
 544               pad-width nil
 545               max-width nil
 546               cut-width nil
 547               ignore-value nil
 548               tilde-form nil
 549               extended-spec nil)
 550         (setq spec-beg (1- (point)))
 551
 552         ;; Parse this spec fully.
 553         (while
 554             (cond
 555              ((looking-at "\\([-.0-9]+\\)\\(,[-0-9]+\\)?")
 556               (setq pad-width (string-to-number (match-string 1)))
 557               (when (match-beginning 2)
 558                 (setq max-width (string-to-number (buffer-substring
 559                                                    (1+ (match-beginning 2))
 560                                                    (match-end 2)))))
 561               (goto-char (match-end 0)))
 562              ((looking-at "~")
 563               (forward-char 1)
 564               (setq tilde (read (current-buffer))
 565                     type (car tilde)
 566                     value (cadr tilde))
 567               (cond
 568                ((memq type '(pad pad-left))
 569                 (setq pad-width value))
 570                ((eq type 'pad-right)
 571                 (setq pad-width (- value)))
 572                ((memq type '(max-right max))
 573                 (setq max-width value))
 574                ((eq type 'max-left)
 575                 (setq max-width (- value)))
 576                ((memq type '(cut cut-left))
 577                 (setq cut-width value))
 578                ((eq type 'cut-right)
 579                 (setq cut-width (- value)))
 580                ((eq type 'ignore)
 581                 (setq ignore-value
 582                       (if (stringp value) value (format "%s" value))))
 583                ((eq type 'form)
 584                 (setq tilde-form value))
 585                (t
 586                 (error "Unknown tilde type: %s" tilde)))
 587               t)
 588              (t
 589               nil)))
 590         (cond
 591          ;; User-defined spec -- find the spec name.
 592          ((eq (setq spec (char-after)) ?u)
 593           (forward-char 1)
 594           (when (and (eq (setq user-defined (char-after)) ?&)
 595                      (looking-at "&\\([^;]+\\);"))
 596             (setq user-defined (match-string 1))
 597             (goto-char (match-end 1))))
 598          ;; extended spec
 599          ((and (eq spec ?&) (looking-at "&\\([^;]+\\);"))
 600           (setq extended-spec (intern (match-string 1)))
 601           (goto-char (match-end 1))))
 602         (forward-char 1)
 603         (delete-region spec-beg (point))
 604
 605         ;; Now we have all the relevant data on this spec, so
 606         ;; we start doing stuff.
 607         (insert "%")
 608         (if (eq spec ?%)
 609             ;; "%%" just results in a "%".
 610             (insert "%")
 611           (cond
 612            ;; Do tilde forms.
 613            ((eq spec ?@)
 614             (setq elem (list tilde-form ?s)))
 615            ;; Treat user defined format specifiers specially.
 616            (user-defined
 617             (setq elem
 618                   (list
 619                    (list (intern (format
 620                                   (if (stringp user-defined)
 621                                       "gnus-user-format-function-%s"
 622                                     "gnus-user-format-function-%c")
 623                                   user-defined))
 624                          'gnus-tmp-header)
 625                    ?s)))
 626            ;; Find the specification from `spec-alist'.
 627            ((setq elem (cdr (assq (or extended-spec spec) spec-alist))))
 628            ;; We used to use "%l" for displaying the grouplens score.
 629            ((eq spec ?l)
 630             (setq elem '("" ?s)))
 631            (t
 632             (setq elem '("*" ?s))))
 633           (setq elem-type (cadr elem))
 634           ;; Insert the new format elements.
 635           (when (and pad-width
 636                      (not (and (featurep 'xemacs)
 637                                gnus-use-correct-string-widths)))
 638             (insert (number-to-string pad-width)))
 639           ;; Create the form to be evaled.
 640           (if (or max-width cut-width ignore-value
 641                   (and (featurep 'xemacs)
 642                        gnus-use-correct-string-widths))
 643               (progn
 644                 (insert ?s)
 645                 (let ((el (car elem)))
 646                   (cond ((= (cadr elem) ?c)
 647                          (setq el (list 'char-to-string el)))
 648                         ((= (cadr elem) ?d)
 649                          (setq el (list 'int-to-string el))))
 650                   (when ignore-value
 651                     (setq el (gnus-tilde-ignore-form el ignore-value)))
 652                   (when cut-width
 653                     (setq el (gnus-tilde-cut-form el cut-width)))
 654                   (when max-width
 655                     (setq el (gnus-tilde-max-form el max-width)))
 656                   (when pad-width
 657                     (setq el (gnus-pad-form el pad-width)))
 658                   (push el flist)))
 659             (insert elem-type)
 660             (push (car elem) flist))))
 661       (setq fstring (buffer-substring-no-properties (point-min) (point-max))))
 662
 663     ;; Do some postprocessing to increase efficiency.
 664     (setq
 665      result
 666      (cond
 667       ;; Emptiness.
 668       ((string= fstring "")
 669        nil)
 670       ;; Not a format string.
 671       ((not (string-match "%" fstring))
 672        (list fstring))
 673       ;; A format string with just a single string spec.
 674       ((string= fstring "%s")
 675        (list (car flist)))
 676       ;; A single character.
 677       ((string= fstring "%c")
 678        (list (car flist)))
 679       ;; A single number.
 680       ((string= fstring "%d")
 681        (setq dontinsert t)
 682        (if insert
 683            (list `(princ ,(car flist)))
 684          (list `(int-to-string ,(car flist)))))
 685       ;; Just lots of chars and strings.
 686       ((string-match "\\`\\(%[cs]\\)+\\'" fstring)
 687        (nreverse flist))
 688       ;; A single string spec at the beginning of the spec.
 689       ((string-match "\\`%[sc][^%]+\\'" fstring)
 690        (list (car flist) (substring fstring 2)))
 691       ;; A single string spec in the middle of the spec.
 692       ((string-match "\\`\\([^%]+\\)%[sc]\\([^%]+\\)\\'" fstring)
 693        (list (match-string 1 fstring) (car flist) (match-string 2 fstring)))
 694       ;; A single string spec in the end of the spec.
 695       ((string-match "\\`\\([^%]+\\)%[sc]\\'" fstring)
 696        (list (match-string 1 fstring) (car flist)))
 697       ;; Only string (and %) specs (XEmacs only!)
 698       ((and (featurep 'xemacs)
 699             gnus-make-format-preserve-properties
 700             (string-match
 701              "\\`\\([^%]*\\(%%\\|%-?\\([1-9][0-9]*\\)?s\\)\\)*[^%]*\\'"
 702              fstring))
 703        (list (cons 'gnus-xmas-format (cons fstring (nreverse flist)))))
 704       ;; A more complex spec.
 705       (t
 706        (list (cons 'format (cons fstring (nreverse flist)))))))
 707
 708     (if insert
 709         (when result
 710           (if dontinsert
 711               result
 712             (cons 'insert result)))
 713       (cond ((stringp result)
 714              result)
 715             ((consp result)
 716              (cons 'concat result))
 717             (t "")))))
 718
 719 (defun gnus-eval-format (format &optional alist props)
 720   "Eval the format variable FORMAT, using ALIST.
 721 If PROPS, insert the result."
 722   (let ((form (gnus-parse-format format alist props)))
 723     (if props
 724         (gnus-add-text-properties (point) (progn (eval form) (point)) props)
 725       (eval form))))
 726
 727 (defun gnus-compile ()
 728   "Byte-compile the user-defined format specs."
 729   (interactive)
 730   (require 'bytecomp)
 731   (let ((entries gnus-format-specs)
 732         (byte-compile-warnings '(unresolved callargs redefine))
 733         entry gnus-tmp-func)
 734     (save-excursion
 735       (gnus-message 7 "Compiling format specs...")
 736
 737       (while entries
 738         (setq entry (pop entries))
 739         (if (memq (car entry) '(gnus-version version))
 740             (setq gnus-format-specs (delq entry gnus-format-specs))
 741           (let ((form (caddr entry)))
 742             (when (and (listp form)
 743                        ;; Under GNU Emacs, it's (byte-code ...)
 744                        (not (eq 'byte-code (car form)))
 745                        ;; Under XEmacs, it's (funcall #<compiled-function ...>)
 746                        (not (and (eq 'funcall (car form))
 747                                  (byte-code-function-p (cadr form)))))
 748               (defalias 'gnus-tmp-func `(lambda () ,form))
 749               (byte-compile 'gnus-tmp-func)
 750               (setcar (cddr entry) (gnus-byte-code 'gnus-tmp-func))))))
 751
 752       (push (cons 'version emacs-version) gnus-format-specs)
 753       ;; Mark the .newsrc.eld file as "dirty".
 754       (gnus-dribble-touch)
 755       (gnus-message 7 "Compiling user specs...done"))))
 756
 757 (defun gnus-set-format (type &optional insertable)
 758   (set (intern (format "gnus-%s-line-format-spec" type))
 759        (gnus-parse-format
 760         (symbol-value (intern (format "gnus-%s-line-format" type)))
 761         (symbol-value (intern (format "gnus-%s-line-format-alist" type)))
 762         insertable)))
 763
 764 (provide 'gnus-spec)
 765
 766 ;; Local Variables:
 767 ;; coding: iso-8859-1
 768 ;; End:
 769
 770 ;;; gnus-spec.el ends here