lisp/gnus/gnus-spec.el

   1 ;;; gnus-spec.el --- format spec functions for Gnus
   2
   3 ;; Copyright (C) 1996-2012 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 evalled 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 (defmacro gnus-lrm-string-p (string)
  94   (if (fboundp 'bidi-string-mark-left-to-right)
  95       ;; LRM, RLM, PDF characters as integers to avoid breaking Emacs
  96       ;; 23.
  97       `(memq (aref ,string (1- (length ,string))) '(8206 8207 8236))
  98     nil))
  99
 100 (defvar gnus-lrm-string (if (ignore-errors (string 8206))
 101                             (propertize (string 8206) 'invisible t)
 102                           ""))
 103
 104 (defun gnus-summary-line-format-spec ()
 105   (insert gnus-tmp-unread gnus-tmp-replied
 106           gnus-tmp-score-char gnus-tmp-indentation)
 107   (gnus-put-text-property
 108    (point)
 109    (progn
 110      (insert
 111       (format "%c%4s: %-23s%c" gnus-tmp-opening-bracket gnus-tmp-lines
 112               (let ((val
 113                      (inline
 114                        (gnus-summary-from-or-to-or-newsgroups
 115                         gnus-tmp-header gnus-tmp-from))))
 116                 (if (> (length val) 23)
 117                     (if (gnus-lrm-string-p val)
 118                         (concat (substring val 0 23) gnus-lrm-string)
 119                       (substring val 0 23))
 120                   val))
 121               gnus-tmp-closing-bracket))
 122      (point))
 123    gnus-mouse-face-prop gnus-mouse-face)
 124   (insert " " gnus-tmp-subject-or-nil "\n"))
 125
 126 (defvar gnus-summary-line-format-spec
 127   (gnus-byte-code 'gnus-summary-line-format-spec))
 128
 129 (defun gnus-summary-dummy-line-format-spec ()
 130   (insert "*  ")
 131   (gnus-put-text-property
 132    (point)
 133    (progn
 134      (insert ":                          :")
 135      (point))
 136    gnus-mouse-face-prop gnus-mouse-face)
 137   (insert " " gnus-tmp-subject "\n"))
 138
 139 (defvar gnus-summary-dummy-line-format-spec
 140   (gnus-byte-code 'gnus-summary-dummy-line-format-spec))
 141
 142 (defun gnus-group-line-format-spec ()
 143   (insert gnus-tmp-marked-mark gnus-tmp-subscribed
 144           gnus-tmp-process-marked
 145           gnus-group-indentation
 146           (format "%5s: " gnus-tmp-number-of-unread))
 147   (gnus-put-text-property
 148    (point)
 149    (progn
 150      (insert gnus-tmp-group "\n")
 151      (1- (point)))
 152    gnus-mouse-face-prop gnus-mouse-face))
 153 (defvar gnus-group-line-format-spec
 154   (gnus-byte-code 'gnus-group-line-format-spec))
 155
 156 (defvar gnus-format-specs
 157   `((version . ,emacs-version)
 158     (gnus-version . ,(gnus-continuum-version))
 159     (group "%M\%S\%p\%P\%5y: %(%g%)\n" ,gnus-group-line-format-spec)
 160     (summary-dummy "*  %(:                          :%) %S\n"
 161                    ,gnus-summary-dummy-line-format-spec)
 162     (summary "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n"
 163              ,gnus-summary-line-format-spec))
 164   "Alist of format specs.")
 165
 166 (defvar gnus-default-format-specs gnus-format-specs)
 167
 168 (defvar gnus-article-mode-line-format-spec nil)
 169 (defvar gnus-summary-mode-line-format-spec nil)
 170 (defvar gnus-group-mode-line-format-spec nil)
 171
 172 ;;; Phew.  All that gruft is over with, fortunately.
 173
 174 ;;;###autoload
 175 (defun gnus-update-format (var)
 176   "Update the format specification near point."
 177   (interactive
 178    (list
 179     (save-excursion
 180       (eval-defun nil)
 181       ;; Find the end of the current word.
 182       (re-search-forward "[ \t\n]" nil t)
 183       ;; Search backward.
 184       (when (re-search-backward "\\(gnus-[-a-z]+-line-format\\)" nil t)
 185         (match-string 1)))))
 186   (let* ((type (intern (progn (string-match "gnus-\\([-a-z]+\\)-line" var)
 187                               (match-string 1 var))))
 188          (entry (assq type gnus-format-specs))
 189          value spec)
 190     (when entry
 191       (setq gnus-format-specs (delq entry gnus-format-specs)))
 192     (set
 193      (intern (format "%s-spec" var))
 194      (gnus-parse-format (setq value (symbol-value (intern var)))
 195                         (symbol-value (intern (format "%s-alist" var)))
 196                         (not (string-match "mode" var))))
 197     (setq spec (symbol-value (intern (format "%s-spec" var))))
 198     (push (list type value spec) gnus-format-specs)
 199
 200     (pop-to-buffer "*Gnus Format*")
 201     (erase-buffer)
 202     (lisp-interaction-mode)
 203     (insert (gnus-pp-to-string spec))))
 204
 205 (defun gnus-update-format-specifications (&optional force &rest types)
 206   "Update all (necessary) format specifications.
 207 Return a list of updated types."
 208   ;; Make the indentation array.
 209   ;; See whether all the stored info needs to be flushed.
 210   (when (or force
 211             (not gnus-newsrc-file-version)
 212             (not (equal (gnus-continuum-version)
 213                         (gnus-continuum-version gnus-newsrc-file-version)))
 214             (not (equal emacs-version
 215                         (cdr (assq 'version gnus-format-specs)))))
 216     (setq gnus-format-specs nil))
 217   ;; Flush the group format spec cache if there's the grouplens stuff
 218   ;; or it doesn't support decoded group names.
 219   (when (memq 'group types)
 220     (let* ((spec (assq 'group gnus-format-specs))
 221            (sspec (gnus-prin1-to-string (nth 2 spec))))
 222       (when (or (string-match " gnus-tmp-grouplens[ )]" sspec)
 223                 (not (string-match " gnus-tmp-decoded-group[ )]" sspec)))
 224         (setq gnus-format-specs (delq spec gnus-format-specs)))))
 225
 226   ;; Go through all the formats and see whether they need updating.
 227   (let (new-format entry type val updated)
 228     (while (setq type (pop types))
 229       ;; Jump to the proper buffer to find out the value of the
 230       ;; variable, if possible.  (It may be buffer-local.)
 231       (save-excursion
 232         (let ((buffer (intern (format "gnus-%s-buffer" type))))
 233           (when (and (boundp buffer)
 234                      (setq val (symbol-value buffer))
 235                      (gnus-buffer-exists-p val))
 236             (set-buffer val))
 237           (setq new-format (symbol-value
 238                             (intern (format "gnus-%s-line-format" type)))))
 239         (setq entry (cdr (assq type gnus-format-specs)))
 240         (if (and (car entry)
 241                  (equal (car entry) new-format))
 242             ;; Use the old format.
 243             (set (intern (format "gnus-%s-line-format-spec" type))
 244                  (cadr entry))
 245           ;; This is a new format.
 246           (setq val
 247                 (if (not (stringp new-format))
 248                     ;; This is a function call or something.
 249                     new-format
 250                   ;; This is a "real" format.
 251                   (gnus-parse-format
 252                    new-format
 253                    (symbol-value
 254                     (intern (format "gnus-%s-line-format-alist" type)))
 255                    (not (string-match "mode$" (symbol-name type))))))
 256           ;; Enter the new format spec into the list.
 257           (if entry
 258               (progn
 259                 (setcar (cdr entry) val)
 260                 (setcar entry new-format))
 261             (push (list type new-format val) gnus-format-specs))
 262           (set (intern (format "gnus-%s-line-format-spec" type)) val)
 263           (push type updated))))
 264
 265     (unless (assq 'version gnus-format-specs)
 266       (push (cons 'version emacs-version) gnus-format-specs))
 267     updated))
 268
 269 (defcustom gnus-mouse-face-0 'highlight
 270   "The \"%(hello%)\" face."
 271   :group 'gnus-format
 272   :type 'face)
 273
 274 (defcustom gnus-mouse-face-1 'highlight
 275   "The \"%1(hello%)\" face."
 276   :group 'gnus-format
 277   :type 'face)
 278
 279 (defcustom gnus-mouse-face-2 'highlight
 280   "The \"%2(hello%)\" face."
 281   :group 'gnus-format
 282   :type 'face)
 283
 284 (defcustom gnus-mouse-face-3 'highlight
 285   "The \"%3(hello%)\" face."
 286   :group 'gnus-format
 287   :type 'face)
 288
 289 (defcustom gnus-mouse-face-4 'highlight
 290   "The \"%4(hello%)\" face."
 291   :group 'gnus-format
 292   :type 'face)
 293
 294 (defun gnus-mouse-face-function (form type)
 295   `(gnus-put-text-property
 296     (point) (progn ,@form (point))
 297     gnus-mouse-face-prop
 298     ,(if (equal type 0)
 299          'gnus-mouse-face
 300        `(quote ,(symbol-value (intern (format "gnus-mouse-face-%d" type)))))))
 301
 302 (defcustom gnus-face-0 'bold
 303   "The \"%{hello%}\" face."
 304   :group 'gnus-format
 305   :type 'face)
 306
 307 (defcustom gnus-face-1 'italic
 308   "The \"%1{hello%}\" face."
 309   :group 'gnus-format
 310   :type 'face)
 311
 312 (defcustom gnus-face-2 'bold-italic
 313   "The \"%2{hello%}\" face."
 314   :group 'gnus-format
 315   :type 'face)
 316
 317 (defcustom gnus-face-3 'bold
 318   "The \"%3{hello%}\" face."
 319   :group 'gnus-format
 320   :type 'face)
 321
 322 (defcustom gnus-face-4 'bold
 323   "The \"%4{hello%}\" face."
 324   :group 'gnus-format
 325   :type 'face)
 326
 327 (defun gnus-face-face-function (form type)
 328   `(gnus-add-text-properties
 329     (point) (progn ,@form (point))
 330     '(gnus-face t face ,(symbol-value (intern (format "gnus-face-%d" type))))))
 331
 332 (defun gnus-balloon-face-function (form type)
 333   `(gnus-put-text-property
 334     (point) (progn ,@form (point))
 335     ,(if (fboundp 'balloon-help-mode)
 336          ''balloon-help
 337        ''help-echo)
 338     ,(intern (format "gnus-balloon-face-%d" type))))
 339
 340 (defun gnus-spec-tab (column)
 341   (if (> column 0)
 342       `(insert-char ?  (max (- ,column (current-column)) 0))
 343     (let ((column (abs column)))
 344       `(if (> (current-column) ,column)
 345            (let ((end (point)))
 346              (if (= (move-to-column ,column) ,column)
 347                  (delete-region (point) end)
 348                (delete-region (1- (point)) end)
 349                (insert " ")))
 350          (insert-char ?  (max (- ,column (current-column)) 0))))))
 351
 352 (defun gnus-correct-length (string)
 353   "Return the correct width of STRING."
 354   (apply #'+ (mapcar #'char-width string)))
 355
 356 (defun gnus-correct-substring (string start &optional end)
 357   (let ((wstart 0)
 358         (wend 0)
 359         (wseek 0)
 360         (seek 0)
 361         (length (length string))
 362         (string (concat string "\0")))
 363     ;; Find the start position.
 364     (while (and (< seek length)
 365                 (< wseek start))
 366       (incf wseek (char-width (aref string seek)))
 367       (incf seek))
 368     (setq wstart seek)
 369     ;; Find the end position.
 370     (while (and (<= seek length)
 371                 (or (not end)
 372                     (<= wseek end)))
 373       (incf wseek (char-width (aref string seek)))
 374       (incf seek))
 375     (setq wend seek)
 376     (substring string wstart (1- wend))))
 377
 378 (defun gnus-string-width-function ()
 379   (cond
 380    (gnus-use-correct-string-widths
 381     'gnus-correct-length)
 382    ((fboundp 'string-width)
 383     'string-width)
 384    (t
 385     'length)))
 386
 387 (defun gnus-substring-function ()
 388   (cond
 389    (gnus-use-correct-string-widths
 390     'gnus-correct-substring)
 391    ((fboundp 'string-width)
 392     'gnus-correct-substring)
 393    (t
 394     'substring)))
 395
 396 (defun gnus-tilde-max-form (el max-width)
 397   "Return a form that limits EL to MAX-WIDTH."
 398   (let ((max (abs max-width))
 399         (length-fun (gnus-string-width-function))
 400         (substring-fun (gnus-substring-function)))
 401     (if (symbolp el)
 402         `(if (> (,length-fun ,el) ,max)
 403              ,(if (< max-width 0)
 404                   `(,substring-fun ,el (- (,length-fun ,el) ,max))
 405                 `(if (gnus-lrm-string-p ,el)
 406                      (concat (,substring-fun ,el 0 ,max) ,gnus-lrm-string)
 407                    (,substring-fun ,el 0 ,max)))
 408            ,el)
 409       `(let ((val (eval ,el)))
 410          (if (> (,length-fun val) ,max)
 411              ,(if (< max-width 0)
 412                   `(,substring-fun val (- (,length-fun val) ,max))
 413                 `(if (gnus-lrm-string-p val)
 414                      (concat (,substring-fun val 0 ,max) ,gnus-lrm-string)
 415                    (,substring-fun val 0 ,max)))
 416            val)))))
 417
 418 (defun gnus-tilde-cut-form (el cut-width)
 419   "Return a form that cuts CUT-WIDTH off of EL."
 420   (let ((cut (abs cut-width))
 421         (length-fun (gnus-string-width-function))
 422         (substring-fun (gnus-substring-function)))
 423     (if (symbolp el)
 424         `(if (> (,length-fun ,el) ,cut)
 425              ,(if (< cut-width 0)
 426                   `(,substring-fun ,el 0 (- (,length-fun ,el) ,cut))
 427                 `(,substring-fun ,el ,cut))
 428            ,el)
 429       `(let ((val (eval ,el)))
 430          (if (> (,length-fun val) ,cut)
 431              ,(if (< cut-width 0)
 432                   `(,substring-fun val 0 (- (,length-fun val) ,cut))
 433                 `(,substring-fun val ,cut))
 434            val)))))
 435
 436 (defun gnus-tilde-ignore-form (el ignore-value)
 437   "Return a form that is blank when EL is IGNORE-VALUE."
 438   (if (symbolp el)
 439       `(if (equal ,el ,ignore-value)
 440            "" ,el)
 441     `(let ((val (eval ,el)))
 442        (if (equal val ,ignore-value)
 443            "" val))))
 444
 445 (defun gnus-pad-form (el pad-width)
 446   "Return a form that pads EL to PAD-WIDTH accounting for multi-column
 447 characters correctly. This is because `format' may pad to columns or to
 448 characters when given a pad value."
 449   (let ((pad (abs pad-width))
 450         (side (< 0 pad-width))
 451         (length-fun (gnus-string-width-function)))
 452     (if (symbolp el)
 453         `(let ((need (- ,pad (,length-fun ,el))))
 454            (if (> need 0)
 455                (concat ,(when side '(make-string need ?\ ))
 456                        ,el
 457                        ,(when (not side) '(make-string need ?\ )))
 458              ,el))
 459       `(let* ((val (eval ,el))
 460               (need (- ,pad (,length-fun val))))
 461          (if (> need 0)
 462              (concat ,(when side '(make-string need ?\ ))
 463                      val
 464                      ,(when (not side) '(make-string need ?\ )))
 465            val)))))
 466
 467 (defun gnus-parse-format (format spec-alist &optional insert)
 468   ;; This function parses the FORMAT string with the help of the
 469   ;; SPEC-ALIST and returns a list that can be eval'ed to return the
 470   ;; string.  If the FORMAT string contains the specifiers %( and %)
 471   ;; the text between them will have the mouse-face text property.
 472   ;; If the FORMAT string contains the specifiers %[ and %], the text between
 473   ;; them will have the balloon-help text property.
 474   (let ((case-fold-search nil))
 475     (if (string-match
 476          "\\`\\(.*\\)%[0-9]?[{(«]\\(.*\\)%[0-9]?[»})]\\(.*\n?\\)\\'\\|%[-0-9]*=\\|%[-0-9]*\\*"
 477          format)
 478         (gnus-parse-complex-format format spec-alist)
 479       ;; This is a simple format.
 480       (gnus-parse-simple-format format spec-alist insert))))
 481
 482 (defun gnus-parse-complex-format (format spec-alist)
 483   (let ((cursor-spec nil))
 484     (save-excursion
 485       (gnus-set-work-buffer)
 486       (insert format)
 487       (goto-char (point-min))
 488       (while (re-search-forward "\"" nil t)
 489         (replace-match "\\\"" nil t))
 490       (goto-char (point-min))
 491       (insert "(\"")
 492       ;; Convert all font specs into font spec lists.
 493       (while (re-search-forward "%\\([0-9]+\\)?\\([«»{}()]\\)" nil t)
 494         (let ((number (if (match-beginning 1)
 495                           (match-string 1) "0"))
 496               (delim (aref (match-string 2) 0)))
 497           (if (or (= delim ?\()
 498                   (= delim ?\{)
 499                   (= delim ?\«))
 500               (replace-match (concat "\"("
 501                                      (cond ((= delim ?\() "mouse")
 502                                            ((= delim ?\{) "face")
 503                                            (t "balloon"))
 504                                      " " number " \"")
 505                              t t)
 506             (replace-match "\")\""))))
 507       (goto-char (point-max))
 508       (insert "\")")
 509       ;; Convert point position commands.
 510       (goto-char (point-min))
 511       (let ((case-fold-search nil))
 512         (while (re-search-forward "%\\([-0-9]+\\)?\\*" nil t)
 513           (replace-match "\"(point)\"" t t)
 514           (setq cursor-spec t)))
 515       ;; Convert TAB commands.
 516       (goto-char (point-min))
 517       (while (re-search-forward "%\\([-0-9]+\\)=" nil t)
 518         (replace-match (format "\"(tab %s)\"" (match-string 1)) t t))
 519       ;; Convert the buffer into the spec.
 520       (goto-char (point-min))
 521       (let ((form (read (current-buffer))))
 522         (if cursor-spec
 523             `(let (gnus-position)
 524                ,@(gnus-complex-form-to-spec form spec-alist)
 525                (if gnus-position
 526                    (gnus-put-text-property gnus-position (1+ gnus-position)
 527                                            'gnus-position t)))
 528           `(progn
 529              ,@(gnus-complex-form-to-spec form spec-alist)))))))
 530
 531 (defun gnus-complex-form-to-spec (form spec-alist)
 532   (delq nil
 533         (mapcar
 534          (lambda (sform)
 535            (cond
 536             ((stringp sform)
 537              (gnus-parse-simple-format sform spec-alist t))
 538             ((eq (car sform) 'point)
 539              '(setq gnus-position (point)))
 540             ((eq (car sform) 'tab)
 541              (gnus-spec-tab (cadr sform)))
 542             (t
 543              (funcall (intern (format "gnus-%s-face-function" (car sform)))
 544                       (gnus-complex-form-to-spec (cddr sform) spec-alist)
 545                       (nth 1 sform)))))
 546          form)))
 547
 548
 549 (defun gnus-xmas-format (fstring &rest args)
 550   "A version of `format' which preserves text properties.
 551
 552 Required for XEmacs, where the built in `format' function strips all text
 553 properties from both the format string and any inserted strings.
 554
 555 Only supports the format sequence %s, and %% for inserting
 556 literal % characters. A pad width and an optional - (to right pad)
 557 are supported for %s."
 558   (let ((re "%%\\|%\\(-\\)?\\([1-9][0-9]*\\)?s")
 559         (n (length args)))
 560     (with-temp-buffer
 561       (insert fstring)
 562       (goto-char (point-min))
 563       (while (re-search-forward re nil t)
 564         (goto-char (match-end 0))
 565         (cond
 566          ((string= (match-string 0) "%%")
 567           (delete-char -1))
 568          (t
 569           (if (null args)
 570               (error 'wrong-number-of-arguments #'my-format n fstring))
 571           (let* ((minlen (string-to-number (or (match-string 2) "")))
 572                  (arg (car args))
 573                  (str (if (stringp arg) arg (format "%s" arg)))
 574                  (lpad (null (match-string 1)))
 575                  (padlen (max 0 (- minlen (length str)))))
 576             (replace-match "")
 577             (if lpad (insert-char ?\  padlen))
 578             (insert str)
 579             (unless lpad (insert-char ?\  padlen))
 580             (setq args (cdr args))))))
 581       (buffer-string))))
 582
 583 (defun gnus-parse-simple-format (format spec-alist &optional insert)
 584   ;; This function parses the FORMAT string with the help of the
 585   ;; SPEC-ALIST and returns a list that can be eval'ed to return a
 586   ;; string.
 587   (let ((max-width 0)
 588         spec flist fstring elem result dontinsert user-defined
 589         type value pad-width spec-beg cut-width ignore-value
 590         tilde-form tilde elem-type extended-spec)
 591     (save-excursion
 592       (gnus-set-work-buffer)
 593       (insert format)
 594       (goto-char (point-min))
 595       (while (re-search-forward "%" nil t)
 596         (setq user-defined nil
 597               spec-beg nil
 598               pad-width nil
 599               max-width nil
 600               cut-width nil
 601               ignore-value nil
 602               tilde-form nil
 603               extended-spec nil)
 604         (setq spec-beg (1- (point)))
 605
 606         ;; Parse this spec fully.
 607         (while
 608             (cond
 609              ((looking-at "\\([-.0-9]+\\)\\(,[-0-9]+\\)?")
 610               (setq pad-width (string-to-number (match-string 1)))
 611               (when (match-beginning 2)
 612                 (setq max-width (string-to-number (buffer-substring
 613                                                    (1+ (match-beginning 2))
 614                                                    (match-end 2)))))
 615               (goto-char (match-end 0)))
 616              ((looking-at "~")
 617               (forward-char 1)
 618               (setq tilde (read (current-buffer))
 619                     type (car tilde)
 620                     value (cadr tilde))
 621               (cond
 622                ((memq type '(pad pad-left))
 623                 (setq pad-width value))
 624                ((eq type 'pad-right)
 625                 (setq pad-width (- value)))
 626                ((memq type '(max-right max))
 627                 (setq max-width value))
 628                ((eq type 'max-left)
 629                 (setq max-width (- value)))
 630                ((memq type '(cut cut-left))
 631                 (setq cut-width value))
 632                ((eq type 'cut-right)
 633                 (setq cut-width (- value)))
 634                ((eq type 'ignore)
 635                 (setq ignore-value
 636                       (if (stringp value) value (format "%s" value))))
 637                ((eq type 'form)
 638                 (setq tilde-form value))
 639                (t
 640                 (error "Unknown tilde type: %s" tilde)))
 641               t)
 642              (t
 643               nil)))
 644         (cond
 645          ;; User-defined spec -- find the spec name.
 646          ((eq (setq spec (char-after)) ?u)
 647           (forward-char 1)
 648           (when (and (eq (setq user-defined (char-after)) ?&)
 649                      (looking-at "&\\([^;]+\\);"))
 650             (setq user-defined (match-string 1))
 651             (goto-char (match-end 1))))
 652          ;; extended spec
 653          ((and (eq spec ?&) (looking-at "&\\([^;]+\\);"))
 654           (setq extended-spec (intern (match-string 1)))
 655           (goto-char (match-end 1))))
 656         (forward-char 1)
 657         (delete-region spec-beg (point))
 658
 659         ;; Now we have all the relevant data on this spec, so
 660         ;; we start doing stuff.
 661         (insert "%")
 662         (if (eq spec ?%)
 663             ;; "%%" just results in a "%".
 664             (insert "%")
 665           (cond
 666            ;; Do tilde forms.
 667            ((eq spec ?@)
 668             (setq elem (list tilde-form ?s)))
 669            ;; Treat user defined format specifiers specially.
 670            (user-defined
 671             (setq elem
 672                   (list
 673                    (list (intern (format
 674                                   (if (stringp user-defined)
 675                                       "gnus-user-format-function-%s"
 676                                     "gnus-user-format-function-%c")
 677                                   user-defined))
 678                          'gnus-tmp-header)
 679                    ?s)))
 680            ;; Find the specification from `spec-alist'.
 681            ((setq elem (cdr (assq (or extended-spec spec) spec-alist))))
 682            ;; We used to use "%l" for displaying the grouplens score.
 683            ((eq spec ?l)
 684             (setq elem '("" ?s)))
 685            (t
 686             (setq elem '("*" ?s))))
 687           (setq elem-type (cadr elem))
 688           ;; Insert the new format elements.
 689           (when (and pad-width
 690                      (not (and (featurep 'xemacs)
 691                                gnus-use-correct-string-widths)))
 692             (insert (number-to-string pad-width)))
 693           ;; Create the form to be evalled.
 694           (if (or max-width cut-width ignore-value
 695                   (and (featurep 'xemacs)
 696                        gnus-use-correct-string-widths))
 697               (progn
 698                 (insert ?s)
 699                 (let ((el (car elem)))
 700                   (cond ((= (cadr elem) ?c)
 701                          (setq el (list 'char-to-string el)))
 702                         ((= (cadr elem) ?d)
 703                          (setq el (list 'int-to-string el))))
 704                   (when ignore-value
 705                     (setq el (gnus-tilde-ignore-form el ignore-value)))
 706                   (when cut-width
 707                     (setq el (gnus-tilde-cut-form el cut-width)))
 708                   (when max-width
 709                     (setq el (gnus-tilde-max-form el max-width)))
 710                   (when pad-width
 711                     (setq el (gnus-pad-form el pad-width)))
 712                   (push el flist)))
 713             (insert elem-type)
 714             (push (car elem) flist))))
 715       (setq fstring (buffer-substring-no-properties (point-min) (point-max))))
 716
 717     ;; Do some postprocessing to increase efficiency.
 718     (setq
 719      result
 720      (cond
 721       ;; Emptiness.
 722       ((string= fstring "")
 723        nil)
 724       ;; Not a format string.
 725       ((not (string-match "%" fstring))
 726        (list fstring))
 727       ;; A format string with just a single string spec.
 728       ((string= fstring "%s")
 729        (list (car flist)))
 730       ;; A single character.
 731       ((string= fstring "%c")
 732        (list (car flist)))
 733       ;; A single number.
 734       ((string= fstring "%d")
 735        (setq dontinsert t)
 736        (if insert
 737            `(insert (int-to-string ,(car flist)))
 738          (list `(int-to-string ,(car flist)))))
 739       ;; Just lots of chars and strings.
 740       ((string-match "\\`\\(%[cs]\\)+\\'" fstring)
 741        (nreverse flist))
 742       ;; A single string spec at the beginning of the spec.
 743       ((string-match "\\`%[sc][^%]+\\'" fstring)
 744        (list (car flist) (substring fstring 2)))
 745       ;; A single string spec in the middle of the spec.
 746       ((string-match "\\`\\([^%]+\\)%[sc]\\([^%]+\\)\\'" fstring)
 747        (list (match-string 1 fstring) (car flist) (match-string 2 fstring)))
 748       ;; A single string spec in the end of the spec.
 749       ((string-match "\\`\\([^%]+\\)%[sc]\\'" fstring)
 750        (list (match-string 1 fstring) (car flist)))
 751       ;; Only string (and %) specs (XEmacs only!)
 752       ((and (featurep 'xemacs)
 753             gnus-make-format-preserve-properties
 754             (string-match
 755              "\\`\\([^%]*\\(%%\\|%-?\\([1-9][0-9]*\\)?s\\)\\)*[^%]*\\'"
 756              fstring))
 757        (list (cons 'gnus-xmas-format (cons fstring (nreverse flist)))))
 758       ;; A more complex spec.
 759       (t
 760        (list (cons 'format (cons fstring (nreverse flist)))))))
 761
 762     (if insert
 763         (when result
 764           (if dontinsert
 765               result
 766             (cons 'insert result)))
 767       (cond ((stringp result)
 768              result)
 769             ((consp result)
 770              (cons 'concat result))
 771             (t "")))))
 772
 773 (defun gnus-eval-format (format &optional alist props)
 774   "Eval the format variable FORMAT, using ALIST.
 775 If PROPS, insert the result."
 776   (let ((form (gnus-parse-format format alist props)))
 777     (if props
 778         (gnus-add-text-properties (point) (progn (eval form) (point)) props)
 779       (eval form))))
 780
 781 (defun gnus-compile ()
 782   "Byte-compile the user-defined format specs."
 783   (interactive)
 784   (require 'bytecomp)
 785   (let ((entries gnus-format-specs)
 786         (byte-compile-warnings '(unresolved callargs redefine))
 787         entry gnus-tmp-func)
 788     (save-excursion
 789       (gnus-message 7 "Compiling format specs...")
 790
 791       (while entries
 792         (setq entry (pop entries))
 793         (if (memq (car entry) '(gnus-version version))
 794             (setq gnus-format-specs (delq entry gnus-format-specs))
 795           (let ((form (caddr entry)))
 796             (when (and (listp form)
 797                        ;; Under GNU Emacs, it's (byte-code ...)
 798                        (not (eq 'byte-code (car form)))
 799                        ;; Under XEmacs, it's (funcall #<compiled-function ...>)
 800                        (not (and (eq 'funcall (car form))
 801                                  (byte-code-function-p (cadr form)))))
 802               (defalias 'gnus-tmp-func `(lambda () ,form))
 803               (byte-compile 'gnus-tmp-func)
 804               (setcar (cddr entry) (gnus-byte-code 'gnus-tmp-func))))))
 805
 806       (push (cons 'version emacs-version) gnus-format-specs)
 807       ;; Mark the .newsrc.eld file as "dirty".
 808       (gnus-dribble-touch)
 809       (gnus-message 7 "Compiling user specs...done"))))
 810
 811 (defun gnus-set-format (type &optional insertable)
 812   (set (intern (format "gnus-%s-line-format-spec" type))
 813        (gnus-parse-format
 814         (symbol-value (intern (format "gnus-%s-line-format" type)))
 815         (symbol-value (intern (format "gnus-%s-line-format-alist" type)))
 816         insertable)))
 817
 818 (provide 'gnus-spec)
 819
 820 ;; Local Variables:
 821 ;; coding: iso-8859-1
 822 ;; End:
 823
 824 ;;; gnus-spec.el ends here