lisp/gnus/gnus-spec.el

   1 ;;; gnus-spec.el --- format spec functions for Gnus
   2
   3 ;; Copyright (C) 1996-2011 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 3 of the License, or
  13 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  27 ;; For Emacs <22.2 and XEmacs.
  28 (eval-and-compile
  29   (unless (fboundp 'declare-function) (defmacro declare-function (&rest r))))
  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 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 (declare-function gnus-summary-from-or-to-or-newsgroups "gnus-sum"
  91                   (header gnus-tmp-from))
  92
  93 (defun gnus-summary-line-format-spec ()
  94   (insert gnus-tmp-unread gnus-tmp-replied
  95           gnus-tmp-score-char gnus-tmp-indentation)
  96   (gnus-put-text-property
  97    (point)
  98    (progn
  99      (insert
 100       (format "%c%4s: %-23s%c" gnus-tmp-opening-bracket gnus-tmp-lines
 101               (let ((val
 102                      (inline
 103                        (gnus-summary-from-or-to-or-newsgroups
 104                         gnus-tmp-header gnus-tmp-from))))
 105                 (if (> (length val) 23)
 106                     (substring val 0 23)
 107                   val))
 108               gnus-tmp-closing-bracket))
 109      (point))
 110    gnus-mouse-face-prop gnus-mouse-face)
 111   (insert " " gnus-tmp-subject-or-nil "\n"))
 112
 113 (defvar gnus-summary-line-format-spec
 114   (gnus-byte-code 'gnus-summary-line-format-spec))
 115
 116 (defun gnus-summary-dummy-line-format-spec ()
 117   (insert "*  ")
 118   (gnus-put-text-property
 119    (point)
 120    (progn
 121      (insert ":                          :")
 122      (point))
 123    gnus-mouse-face-prop gnus-mouse-face)
 124   (insert " " gnus-tmp-subject "\n"))
 125
 126 (defvar gnus-summary-dummy-line-format-spec
 127   (gnus-byte-code 'gnus-summary-dummy-line-format-spec))
 128
 129 (defun gnus-group-line-format-spec ()
 130   (insert gnus-tmp-marked-mark gnus-tmp-subscribed
 131           gnus-tmp-process-marked
 132           gnus-group-indentation
 133           (format "%5s: " gnus-tmp-number-of-unread))
 134   (gnus-put-text-property
 135    (point)
 136    (progn
 137      (insert gnus-tmp-group "\n")
 138      (1- (point)))
 139    gnus-mouse-face-prop gnus-mouse-face))
 140 (defvar gnus-group-line-format-spec
 141   (gnus-byte-code 'gnus-group-line-format-spec))
 142
 143 (defvar gnus-format-specs
 144   `((version . ,emacs-version)
 145     (gnus-version . ,(gnus-continuum-version))
 146     (group "%M\%S\%p\%P\%5y: %(%g%)\n" ,gnus-group-line-format-spec)
 147     (summary-dummy "*  %(:                          :%) %S\n"
 148                    ,gnus-summary-dummy-line-format-spec)
 149     (summary "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n"
 150              ,gnus-summary-line-format-spec))
 151   "Alist of format specs.")
 152
 153 (defvar gnus-default-format-specs gnus-format-specs)
 154
 155 (defvar gnus-article-mode-line-format-spec nil)
 156 (defvar gnus-summary-mode-line-format-spec nil)
 157 (defvar gnus-group-mode-line-format-spec nil)
 158
 159 ;;; Phew.  All that gruft is over with, fortunately.
 160
 161 ;;;###autoload
 162 (defun gnus-update-format (var)
 163   "Update the format specification near point."
 164   (interactive
 165    (list
 166     (save-excursion
 167       (eval-defun nil)
 168       ;; Find the end of the current word.
 169       (re-search-forward "[ \t\n]" nil t)
 170       ;; Search backward.
 171       (when (re-search-backward "\\(gnus-[-a-z]+-line-format\\)" nil t)
 172         (match-string 1)))))
 173   (let* ((type (intern (progn (string-match "gnus-\\([-a-z]+\\)-line" var)
 174                               (match-string 1 var))))
 175          (entry (assq type gnus-format-specs))
 176          value spec)
 177     (when entry
 178       (setq gnus-format-specs (delq entry gnus-format-specs)))
 179     (set
 180      (intern (format "%s-spec" var))
 181      (gnus-parse-format (setq value (symbol-value (intern var)))
 182                         (symbol-value (intern (format "%s-alist" var)))
 183                         (not (string-match "mode" var))))
 184     (setq spec (symbol-value (intern (format "%s-spec" var))))
 185     (push (list type value spec) gnus-format-specs)
 186
 187     (pop-to-buffer "*Gnus Format*")
 188     (erase-buffer)
 189     (lisp-interaction-mode)
 190     (insert (gnus-pp-to-string spec))))
 191
 192 (defun gnus-update-format-specifications (&optional force &rest types)
 193   "Update all (necessary) format specifications.
 194 Return a list of updated types."
 195   ;; Make the indentation array.
 196   ;; See whether all the stored info needs to be flushed.
 197   (when (or force
 198             (not gnus-newsrc-file-version)
 199             (not (equal (gnus-continuum-version)
 200                         (gnus-continuum-version gnus-newsrc-file-version)))
 201             (not (equal emacs-version
 202                         (cdr (assq 'version gnus-format-specs)))))
 203     (setq gnus-format-specs nil))
 204   ;; Flush the group format spec cache if there's the grouplens stuff
 205   ;; or it doesn't support decoded group names.
 206   (when (memq 'group types)
 207     (let* ((spec (assq 'group gnus-format-specs))
 208            (sspec (gnus-prin1-to-string (nth 2 spec))))
 209       (when (or (string-match " gnus-tmp-grouplens[ )]" sspec)
 210                 (not (string-match " gnus-tmp-decoded-group[ )]" sspec)))
 211         (setq gnus-format-specs (delq spec gnus-format-specs)))))
 212
 213   ;; Go through all the formats and see whether they need updating.
 214   (let (new-format entry type val updated)
 215     (while (setq type (pop types))
 216       ;; Jump to the proper buffer to find out the value of the
 217       ;; variable, if possible.  (It may be buffer-local.)
 218       (save-excursion
 219         (let ((buffer (intern (format "gnus-%s-buffer" type))))
 220           (when (and (boundp buffer)
 221                      (setq val (symbol-value buffer))
 222                      (gnus-buffer-exists-p val))
 223             (set-buffer val))
 224           (setq new-format (symbol-value
 225                             (intern (format "gnus-%s-line-format" type)))))
 226         (setq entry (cdr (assq type gnus-format-specs)))
 227         (if (and (car entry)
 228                  (equal (car entry) new-format))
 229             ;; Use the old format.
 230             (set (intern (format "gnus-%s-line-format-spec" type))
 231                  (cadr entry))
 232           ;; This is a new format.
 233           (setq val
 234                 (if (not (stringp new-format))
 235                     ;; This is a function call or something.
 236                     new-format
 237                   ;; This is a "real" format.
 238                   (gnus-parse-format
 239                    new-format
 240                    (symbol-value
 241                     (intern (format "gnus-%s-line-format-alist" type)))
 242                    (not (string-match "mode$" (symbol-name type))))))
 243           ;; Enter the new format spec into the list.
 244           (if entry
 245               (progn
 246                 (setcar (cdr entry) val)
 247                 (setcar entry new-format))
 248             (push (list type new-format val) gnus-format-specs))
 249           (set (intern (format "gnus-%s-line-format-spec" type)) val)
 250           (push type updated))))
 251
 252     (unless (assq 'version gnus-format-specs)
 253       (push (cons 'version emacs-version) gnus-format-specs))
 254     updated))
 255
 256 (defvar gnus-mouse-face-0 'highlight)
 257 (defvar gnus-mouse-face-1 'highlight)
 258 (defvar gnus-mouse-face-2 'highlight)
 259 (defvar gnus-mouse-face-3 'highlight)
 260 (defvar gnus-mouse-face-4 'highlight)
 261
 262 (defun gnus-mouse-face-function (form type)
 263   `(gnus-put-text-property
 264     (point) (progn ,@form (point))
 265     gnus-mouse-face-prop
 266     ,(if (equal type 0)
 267          'gnus-mouse-face
 268        `(quote ,(symbol-value (intern (format "gnus-mouse-face-%d" type)))))))
 269
 270 (defvar gnus-face-0 'bold)
 271 (defvar gnus-face-1 'italic)
 272 (defvar gnus-face-2 'bold-italic)
 273 (defvar gnus-face-3 'bold)
 274 (defvar gnus-face-4 'bold)
 275
 276 (defun gnus-face-face-function (form type)
 277   `(gnus-add-text-properties
 278     (point) (progn ,@form (point))
 279     '(gnus-face t face ,(symbol-value (intern (format "gnus-face-%d" type))))))
 280
 281 (defun gnus-balloon-face-function (form type)
 282   `(gnus-put-text-property
 283     (point) (progn ,@form (point))
 284     ,(if (fboundp 'balloon-help-mode)
 285          ''balloon-help
 286        ''help-echo)
 287     ,(intern (format "gnus-balloon-face-%d" type))))
 288
 289 (defun gnus-spec-tab (column)
 290   (if (> column 0)
 291       `(insert-char ?  (max (- ,column (current-column)) 0))
 292     (let ((column (abs column)))
 293       `(if (> (current-column) ,column)
 294            (let ((end (point)))
 295              (if (= (move-to-column ,column) ,column)
 296                  (delete-region (point) end)
 297                (delete-region (1- (point)) end)
 298                (insert " ")))
 299          (insert-char ?  (max (- ,column (current-column)) 0))))))
 300
 301 (defun gnus-correct-length (string)
 302   "Return the correct width of STRING."
 303   (apply #'+ (mapcar #'char-width string)))
 304
 305 (defun gnus-correct-substring (string start &optional end)
 306   (let ((wstart 0)
 307         (wend 0)
 308         (wseek 0)
 309         (seek 0)
 310         (length (length string))
 311         (string (concat string "\0")))
 312     ;; Find the start position.
 313     (while (and (< seek length)
 314                 (< wseek start))
 315       (incf wseek (char-width (aref string seek)))
 316       (incf seek))
 317     (setq wstart seek)
 318     ;; Find the end position.
 319     (while (and (<= seek length)
 320                 (or (not end)
 321                     (<= wseek end)))
 322       (incf wseek (char-width (aref string seek)))
 323       (incf seek))
 324     (setq wend seek)
 325     (substring string wstart (1- wend))))
 326
 327 (defun gnus-string-width-function ()
 328   (cond
 329    (gnus-use-correct-string-widths
 330     'gnus-correct-length)
 331    ((fboundp 'string-width)
 332     'string-width)
 333    (t
 334     'length)))
 335
 336 (defun gnus-substring-function ()
 337   (cond
 338    (gnus-use-correct-string-widths
 339     'gnus-correct-substring)
 340    ((fboundp 'string-width)
 341     'gnus-correct-substring)
 342    (t
 343     'substring)))
 344
 345 (defun gnus-tilde-max-form (el max-width)
 346   "Return a form that limits EL to MAX-WIDTH."
 347   (let ((max (abs max-width))
 348         (length-fun (gnus-string-width-function))
 349         (substring-fun (gnus-substring-function)))
 350     (if (symbolp el)
 351         `(if (> (,length-fun ,el) ,max)
 352              ,(if (< max-width 0)
 353                   `(,substring-fun ,el (- (,length-fun ,el) ,max))
 354                 `(,substring-fun ,el 0 ,max))
 355            ,el)
 356       `(let ((val (eval ,el)))
 357          (if (> (,length-fun val) ,max)
 358              ,(if (< max-width 0)
 359                   `(,substring-fun val (- (,length-fun val) ,max))
 360                 `(,substring-fun val 0 ,max))
 361            val)))))
 362
 363 (defun gnus-tilde-cut-form (el cut-width)
 364   "Return a form that cuts CUT-WIDTH off of EL."
 365   (let ((cut (abs cut-width))
 366         (length-fun (gnus-string-width-function))
 367         (substring-fun (gnus-substring-function)))
 368     (if (symbolp el)
 369         `(if (> (,length-fun ,el) ,cut)
 370              ,(if (< cut-width 0)
 371                   `(,substring-fun ,el 0 (- (,length-fun ,el) ,cut))
 372                 `(,substring-fun ,el ,cut))
 373            ,el)
 374       `(let ((val (eval ,el)))
 375          (if (> (,length-fun val) ,cut)
 376              ,(if (< cut-width 0)
 377                   `(,substring-fun val 0 (- (,length-fun val) ,cut))
 378                 `(,substring-fun val ,cut))
 379            val)))))
 380
 381 (defun gnus-tilde-ignore-form (el ignore-value)
 382   "Return a form that is blank when EL is IGNORE-VALUE."
 383   (if (symbolp el)
 384       `(if (equal ,el ,ignore-value)
 385            "" ,el)
 386     `(let ((val (eval ,el)))
 387        (if (equal val ,ignore-value)
 388            "" val))))
 389
 390 (defun gnus-pad-form (el pad-width)
 391   "Return a form that pads EL to PAD-WIDTH accounting for multi-column
 392 characters correctly. This is because `format' may pad to columns or to
 393 characters when given a pad value."
 394   (let ((pad (abs pad-width))
 395         (side (< 0 pad-width))
 396         (length-fun (gnus-string-width-function)))
 397     (if (symbolp el)
 398         `(let ((need (- ,pad (,length-fun ,el))))
 399            (if (> need 0)
 400                (concat ,(when side '(make-string need ?\ ))
 401                        ,el
 402                        ,(when (not side) '(make-string need ?\ )))
 403              ,el))
 404       `(let* ((val (eval ,el))
 405               (need (- ,pad (,length-fun val))))
 406          (if (> need 0)
 407              (concat ,(when side '(make-string need ?\ ))
 408                      val
 409                      ,(when (not side) '(make-string need ?\ )))
 410            val)))))
 411
 412 (defun gnus-parse-format (format spec-alist &optional insert)
 413   ;; This function parses the FORMAT string with the help of the
 414   ;; SPEC-ALIST and returns a list that can be eval'ed to return the
 415   ;; string.  If the FORMAT string contains the specifiers %( and %)
 416   ;; the text between them will have the mouse-face text property.
 417   ;; If the FORMAT string contains the specifiers %[ and %], the text between
 418   ;; them will have the balloon-help text property.
 419   (let ((case-fold-search nil))
 420     (if (string-match
 421          "\\`\\(.*\\)%[0-9]?[{(«]\\(.*\\)%[0-9]?[»})]\\(.*\n?\\)\\'\\|%[-0-9]*=\\|%[-0-9]*\\*"
 422          format)
 423         (gnus-parse-complex-format format spec-alist)
 424       ;; This is a simple format.
 425       (gnus-parse-simple-format format spec-alist insert))))
 426
 427 (defun gnus-parse-complex-format (format spec-alist)
 428   (let ((cursor-spec nil))
 429     (save-excursion
 430       (gnus-set-work-buffer)
 431       (insert format)
 432       (goto-char (point-min))
 433       (while (re-search-forward "\"" nil t)
 434         (replace-match "\\\"" nil t))
 435       (goto-char (point-min))
 436       (insert "(\"")
 437       ;; Convert all font specs into font spec lists.
 438       (while (re-search-forward "%\\([0-9]+\\)?\\([«»{}()]\\)" nil t)
 439         (let ((number (if (match-beginning 1)
 440                           (match-string 1) "0"))
 441               (delim (aref (match-string 2) 0)))
 442           (if (or (= delim ?\()
 443                   (= delim ?\{)
 444                   (= delim ?\«))
 445               (replace-match (concat "\"("
 446                                      (cond ((= delim ?\() "mouse")
 447                                            ((= delim ?\{) "face")
 448                                            (t "balloon"))
 449                                      " " number " \"")
 450                              t t)
 451             (replace-match "\")\""))))
 452       (goto-char (point-max))
 453       (insert "\")")
 454       ;; Convert point position commands.
 455       (goto-char (point-min))
 456       (let ((case-fold-search nil))
 457         (while (re-search-forward "%\\([-0-9]+\\)?\\*" nil t)
 458           (replace-match "\"(point)\"" t t)
 459           (setq cursor-spec t)))
 460       ;; Convert TAB commands.
 461       (goto-char (point-min))
 462       (while (re-search-forward "%\\([-0-9]+\\)=" nil t)
 463         (replace-match (format "\"(tab %s)\"" (match-string 1)) t t))
 464       ;; Convert the buffer into the spec.
 465       (goto-char (point-min))
 466       (let ((form (read (current-buffer))))
 467         (if cursor-spec
 468             `(let (gnus-position)
 469                ,@(gnus-complex-form-to-spec form spec-alist)
 470                (if gnus-position
 471                    (gnus-put-text-property gnus-position (1+ gnus-position)
 472                                            'gnus-position t)))
 473           `(progn
 474              ,@(gnus-complex-form-to-spec form spec-alist)))))))
 475
 476 (defun gnus-complex-form-to-spec (form spec-alist)
 477   (delq nil
 478         (mapcar
 479          (lambda (sform)
 480            (cond
 481             ((stringp sform)
 482              (gnus-parse-simple-format sform spec-alist t))
 483             ((eq (car sform) 'point)
 484              '(setq gnus-position (point)))
 485             ((eq (car sform) 'tab)
 486              (gnus-spec-tab (cadr sform)))
 487             (t
 488              (funcall (intern (format "gnus-%s-face-function" (car sform)))
 489                       (gnus-complex-form-to-spec (cddr sform) spec-alist)
 490                       (nth 1 sform)))))
 491          form)))
 492
 493
 494 (defun gnus-xmas-format (fstring &rest args)
 495   "A version of `format' which preserves text properties.
 496
 497 Required for XEmacs, where the built in `format' function strips all text
 498 properties from both the format string and any inserted strings.
 499
 500 Only supports the format sequence %s, and %% for inserting
 501 literal % characters. A pad width and an optional - (to right pad)
 502 are supported for %s."
 503   (let ((re "%%\\|%\\(-\\)?\\([1-9][0-9]*\\)?s")
 504         (n (length args)))
 505     (with-temp-buffer
 506       (insert fstring)
 507       (goto-char (point-min))
 508       (while (re-search-forward re nil t)
 509         (goto-char (match-end 0))
 510         (cond
 511          ((string= (match-string 0) "%%")
 512           (delete-char -1))
 513          (t
 514           (if (null args)
 515               (error 'wrong-number-of-arguments #'my-format n fstring))
 516           (let* ((minlen (string-to-number (or (match-string 2) "")))
 517                  (arg (car args))
 518                  (str (if (stringp arg) arg (format "%s" arg)))
 519                  (lpad (null (match-string 1)))
 520                  (padlen (max 0 (- minlen (length str)))))
 521             (replace-match "")
 522             (if lpad (insert-char ?\  padlen))
 523             (insert str)
 524             (unless lpad (insert-char ?\  padlen))
 525             (setq args (cdr args))))))
 526       (buffer-string))))
 527
 528 (defun gnus-parse-simple-format (format spec-alist &optional insert)
 529   ;; This function parses the FORMAT string with the help of the
 530   ;; SPEC-ALIST and returns a list that can be eval'ed to return a
 531   ;; string.
 532   (let ((max-width 0)
 533         spec flist fstring elem result dontinsert user-defined
 534         type value pad-width spec-beg cut-width ignore-value
 535         tilde-form tilde elem-type extended-spec)
 536     (save-excursion
 537       (gnus-set-work-buffer)
 538       (insert format)
 539       (goto-char (point-min))
 540       (while (re-search-forward "%" nil t)
 541         (setq user-defined nil
 542               spec-beg nil
 543               pad-width nil
 544               max-width nil
 545               cut-width nil
 546               ignore-value nil
 547               tilde-form nil
 548               extended-spec nil)
 549         (setq spec-beg (1- (point)))
 550
 551         ;; Parse this spec fully.
 552         (while
 553             (cond
 554              ((looking-at "\\([-.0-9]+\\)\\(,[-0-9]+\\)?")
 555               (setq pad-width (string-to-number (match-string 1)))
 556               (when (match-beginning 2)
 557                 (setq max-width (string-to-number (buffer-substring
 558                                                    (1+ (match-beginning 2))
 559                                                    (match-end 2)))))
 560               (goto-char (match-end 0)))
 561              ((looking-at "~")
 562               (forward-char 1)
 563               (setq tilde (read (current-buffer))
 564                     type (car tilde)
 565                     value (cadr tilde))
 566               (cond
 567                ((memq type '(pad pad-left))
 568                 (setq pad-width value))
 569                ((eq type 'pad-right)
 570                 (setq pad-width (- value)))
 571                ((memq type '(max-right max))
 572                 (setq max-width value))
 573                ((eq type 'max-left)
 574                 (setq max-width (- value)))
 575                ((memq type '(cut cut-left))
 576                 (setq cut-width value))
 577                ((eq type 'cut-right)
 578                 (setq cut-width (- value)))
 579                ((eq type 'ignore)
 580                 (setq ignore-value
 581                       (if (stringp value) value (format "%s" value))))
 582                ((eq type 'form)
 583                 (setq tilde-form value))
 584                (t
 585                 (error "Unknown tilde type: %s" tilde)))
 586               t)
 587              (t
 588               nil)))
 589         (cond
 590          ;; User-defined spec -- find the spec name.
 591          ((eq (setq spec (char-after)) ?u)
 592           (forward-char 1)
 593           (when (and (eq (setq user-defined (char-after)) ?&)
 594                      (looking-at "&\\([^;]+\\);"))
 595             (setq user-defined (match-string 1))
 596             (goto-char (match-end 1))))
 597          ;; extended spec
 598          ((and (eq spec ?&) (looking-at "&\\([^;]+\\);"))
 599           (setq extended-spec (intern (match-string 1)))
 600           (goto-char (match-end 1))))
 601         (forward-char 1)
 602         (delete-region spec-beg (point))
 603
 604         ;; Now we have all the relevant data on this spec, so
 605         ;; we start doing stuff.
 606         (insert "%")
 607         (if (eq spec ?%)
 608             ;; "%%" just results in a "%".
 609             (insert "%")
 610           (cond
 611            ;; Do tilde forms.
 612            ((eq spec ?@)
 613             (setq elem (list tilde-form ?s)))
 614            ;; Treat user defined format specifiers specially.
 615            (user-defined
 616             (setq elem
 617                   (list
 618                    (list (intern (format
 619                                   (if (stringp user-defined)
 620                                       "gnus-user-format-function-%s"
 621                                     "gnus-user-format-function-%c")
 622                                   user-defined))
 623                          'gnus-tmp-header)
 624                    ?s)))
 625            ;; Find the specification from `spec-alist'.
 626            ((setq elem (cdr (assq (or extended-spec spec) spec-alist))))
 627            ;; We used to use "%l" for displaying the grouplens score.
 628            ((eq spec ?l)
 629             (setq elem '("" ?s)))
 630            (t
 631             (setq elem '("*" ?s))))
 632           (setq elem-type (cadr elem))
 633           ;; Insert the new format elements.
 634           (when (and pad-width
 635                      (not (and (featurep 'xemacs)
 636                                gnus-use-correct-string-widths)))
 637             (insert (number-to-string pad-width)))
 638           ;; Create the form to be evaled.
 639           (if (or max-width cut-width ignore-value
 640                   (and (featurep 'xemacs)
 641                        gnus-use-correct-string-widths))
 642               (progn
 643                 (insert ?s)
 644                 (let ((el (car elem)))
 645                   (cond ((= (cadr elem) ?c)
 646                          (setq el (list 'char-to-string el)))
 647                         ((= (cadr elem) ?d)
 648                          (setq el (list 'int-to-string el))))
 649                   (when ignore-value
 650                     (setq el (gnus-tilde-ignore-form el ignore-value)))
 651                   (when cut-width
 652                     (setq el (gnus-tilde-cut-form el cut-width)))
 653                   (when max-width
 654                     (setq el (gnus-tilde-max-form el max-width)))
 655                   (when pad-width
 656                     (setq el (gnus-pad-form el pad-width)))
 657                   (push el flist)))
 658             (insert elem-type)
 659             (push (car elem) flist))))
 660       (setq fstring (buffer-substring-no-properties (point-min) (point-max))))
 661
 662     ;; Do some postprocessing to increase efficiency.
 663     (setq
 664      result
 665      (cond
 666       ;; Emptiness.
 667       ((string= fstring "")
 668        nil)
 669       ;; Not a format string.
 670       ((not (string-match "%" fstring))
 671        (list fstring))
 672       ;; A format string with just a single string spec.
 673       ((string= fstring "%s")
 674        (list (car flist)))
 675       ;; A single character.
 676       ((string= fstring "%c")
 677        (list (car flist)))
 678       ;; A single number.
 679       ((string= fstring "%d")
 680        (setq dontinsert t)
 681        (if insert
 682            `(insert (int-to-string ,(car flist)))
 683          (list `(int-to-string ,(car flist)))))
 684       ;; Just lots of chars and strings.
 685       ((string-match "\\`\\(%[cs]\\)+\\'" fstring)
 686        (nreverse flist))
 687       ;; A single string spec at the beginning of the spec.
 688       ((string-match "\\`%[sc][^%]+\\'" fstring)
 689        (list (car flist) (substring fstring 2)))
 690       ;; A single string spec in the middle of the spec.
 691       ((string-match "\\`\\([^%]+\\)%[sc]\\([^%]+\\)\\'" fstring)
 692        (list (match-string 1 fstring) (car flist) (match-string 2 fstring)))
 693       ;; A single string spec in the end of the spec.
 694       ((string-match "\\`\\([^%]+\\)%[sc]\\'" fstring)
 695        (list (match-string 1 fstring) (car flist)))
 696       ;; Only string (and %) specs (XEmacs only!)
 697       ((and (featurep 'xemacs)
 698             gnus-make-format-preserve-properties
 699             (string-match
 700              "\\`\\([^%]*\\(%%\\|%-?\\([1-9][0-9]*\\)?s\\)\\)*[^%]*\\'"
 701              fstring))
 702        (list (cons 'gnus-xmas-format (cons fstring (nreverse flist)))))
 703       ;; A more complex spec.
 704       (t
 705        (list (cons 'format (cons fstring (nreverse flist)))))))
 706
 707     (if insert
 708         (when result
 709           (if dontinsert
 710               result
 711             (cons 'insert result)))
 712       (cond ((stringp result)
 713              result)
 714             ((consp result)
 715              (cons 'concat result))
 716             (t "")))))
 717
 718 (defun gnus-eval-format (format &optional alist props)
 719   "Eval the format variable FORMAT, using ALIST.
 720 If PROPS, insert the result."
 721   (let ((form (gnus-parse-format format alist props)))
 722     (if props
 723         (gnus-add-text-properties (point) (progn (eval form) (point)) props)
 724       (eval form))))
 725
 726 (defun gnus-compile ()
 727   "Byte-compile the user-defined format specs."
 728   (interactive)
 729   (require 'bytecomp)
 730   (let ((entries gnus-format-specs)
 731         (byte-compile-warnings '(unresolved callargs redefine))
 732         entry gnus-tmp-func)
 733     (save-excursion
 734       (gnus-message 7 "Compiling format specs...")
 735
 736       (while entries
 737         (setq entry (pop entries))
 738         (if (memq (car entry) '(gnus-version version))
 739             (setq gnus-format-specs (delq entry gnus-format-specs))
 740           (let ((form (caddr entry)))
 741             (when (and (listp form)
 742                        ;; Under GNU Emacs, it's (byte-code ...)
 743                        (not (eq 'byte-code (car form)))
 744                        ;; Under XEmacs, it's (funcall #<compiled-function ...>)
 745                        (not (and (eq 'funcall (car form))
 746                                  (byte-code-function-p (cadr form)))))
 747               (defalias 'gnus-tmp-func `(lambda () ,form))
 748               (byte-compile 'gnus-tmp-func)
 749               (setcar (cddr entry) (gnus-byte-code 'gnus-tmp-func))))))
 750
 751       (push (cons 'version emacs-version) gnus-format-specs)
 752       ;; Mark the .newsrc.eld file as "dirty".
 753       (gnus-dribble-touch)
 754       (gnus-message 7 "Compiling user specs...done"))))
 755
 756 (defun gnus-set-format (type &optional insertable)
 757   (set (intern (format "gnus-%s-line-format-spec" type))
 758        (gnus-parse-format
 759         (symbol-value (intern (format "gnus-%s-line-format" type)))
 760         (symbol-value (intern (format "gnus-%s-line-format-alist" type)))
 761         insertable)))
 762
 763 (provide 'gnus-spec)
 764
 765 ;; Local Variables:
 766 ;; coding: iso-8859-1
 767 ;; End:
 768
 769 ;;; gnus-spec.el ends here