lisp/gnus/ietf-drums.el

   1 ;;; ietf-drums.el --- Functions for parsing RFC822bis headers
   2
   3 ;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   5
   6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software: you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;; DRUMS is an IETF Working Group that works (or worked) on the
  25 ;; successor to RFC822, "Standard For The Format Of Arpa Internet Text
  26 ;; Messages".  This library is based on
  27 ;; draft-ietf-drums-msg-fmt-05.txt, released on 1998-08-05.
  28
  29 ;; Pending a real regression self test suite, Simon Josefsson added
  30 ;; various self test expressions snipped from bug reports, and their
  31 ;; expected value, below.  I you believe it could be useful, please
  32 ;; add your own test cases, or write a real self test suite, or just
  33 ;; remove this.
  34
  35 ;; <m3oekvfd50.fsf@whitebox.m5r.de>
  36 ;; (ietf-drums-parse-address "'foo' <foo@example.com>")
  37 ;; => ("foo@example.com" . "'foo'")
  38
  39 ;;; Code:
  40
  41 (eval-when-compile (require 'cl))
  42 (require 'time-date)
  43 (require 'mm-util)
  44
  45 (defvar ietf-drums-no-ws-ctl-token "\001-\010\013\014\016-\037\177"
  46   "US-ASCII control characters excluding CR, LF and white space.")
  47 (defvar ietf-drums-text-token "\001-\011\013\014\016-\177"
  48   "US-ASCII characters excluding CR and LF.")
  49 (defvar ietf-drums-specials-token "()<>[]:;@\\,.\""
  50   "Special characters.")
  51 (defvar ietf-drums-quote-token "\\"
  52   "Quote character.")
  53 (defvar ietf-drums-wsp-token " \t"
  54   "White space.")
  55 (defvar ietf-drums-fws-regexp
  56   (concat "[" ietf-drums-wsp-token "]*\n[" ietf-drums-wsp-token "]+")
  57   "Folding white space.")
  58 (defvar ietf-drums-atext-token "-^a-zA-Z0-9!#$%&'*+/=?_`{|}~"
  59   "Textual token.")
  60 (defvar ietf-drums-dot-atext-token "-^a-zA-Z0-9!#$%&'*+/=?_`{|}~."
  61   "Textual token including full stop.")
  62 (defvar ietf-drums-qtext-token
  63   (concat ietf-drums-no-ws-ctl-token "\041\043-\133\135-\177")
  64   "Non-white-space control characters, plus the rest of ASCII excluding
  65 backslash and doublequote.")
  66 (defvar ietf-drums-tspecials "][()<>@,;:\\\"/?="
  67   "Tspecials.")
  68
  69 (defvar ietf-drums-syntax-table
  70   (let ((table (copy-syntax-table emacs-lisp-mode-syntax-table)))
  71     (modify-syntax-entry ?\\ "/" table)
  72     (modify-syntax-entry ?< "(" table)
  73     (modify-syntax-entry ?> ")" table)
  74     (modify-syntax-entry ?@ "w" table)
  75     (modify-syntax-entry ?/ "w" table)
  76     (modify-syntax-entry ?* "_" table)
  77     (modify-syntax-entry ?\; "_" table)
  78     (modify-syntax-entry ?\' "_" table)
  79     (if (featurep 'xemacs)
  80         (let ((i 128))
  81           (while (< i 256)
  82             (modify-syntax-entry i "w" table)
  83             (setq i (1+ i)))))
  84     table))
  85
  86 (defun ietf-drums-token-to-list (token)
  87   "Translate TOKEN into a list of characters."
  88   (let ((i 0)
  89         b e c out range)
  90     (while (< i (length token))
  91       (setq c (mm-char-int (aref token i)))
  92       (incf i)
  93       (cond
  94        ((eq c (mm-char-int ?-))
  95         (if b
  96             (setq range t)
  97           (push c out)))
  98        (range
  99         (while (<= b c)
 100           (push (make-char 'ascii b) out)
 101           (incf b))
 102         (setq range nil))
 103        ((= i (length token))
 104         (push (make-char 'ascii c) out))
 105        (t
 106         (when b
 107           (push (make-char 'ascii b) out))
 108         (setq b c))))
 109     (nreverse out)))
 110
 111 (defsubst ietf-drums-init (string)
 112   (set-syntax-table ietf-drums-syntax-table)
 113   (insert string)
 114   (ietf-drums-unfold-fws)
 115   (goto-char (point-min)))
 116
 117 (defun ietf-drums-remove-comments (string)
 118   "Remove comments from STRING."
 119   (with-temp-buffer
 120     (let (c)
 121       (ietf-drums-init string)
 122       (while (not (eobp))
 123         (setq c (char-after))
 124         (cond
 125          ((eq c ?\")
 126           (forward-sexp 1))
 127          ((eq c ?\()
 128           (delete-region (point) (progn (forward-sexp 1) (point))))
 129          (t
 130           (forward-char 1))))
 131       (buffer-string))))
 132
 133 (defun ietf-drums-remove-whitespace (string)
 134   "Remove whitespace from STRING."
 135   (with-temp-buffer
 136     (ietf-drums-init string)
 137     (let (c)
 138       (while (not (eobp))
 139         (setq c (char-after))
 140         (cond
 141          ((eq c ?\")
 142           (forward-sexp 1))
 143          ((eq c ?\()
 144           (forward-sexp 1))
 145          ((memq c '(?\  ?\t ?\n))
 146           (delete-char 1))
 147          (t
 148           (forward-char 1))))
 149       (buffer-string))))
 150
 151 (defun ietf-drums-get-comment (string)
 152   "Return the first comment in STRING."
 153   (with-temp-buffer
 154     (ietf-drums-init string)
 155     (let (result c)
 156       (while (not (eobp))
 157         (setq c (char-after))
 158         (cond
 159          ((eq c ?\")
 160           (forward-sexp 1))
 161          ((eq c ?\()
 162           (setq result
 163                 (buffer-substring
 164                  (1+ (point))
 165                  (progn (forward-sexp 1) (1- (point))))))
 166          (t
 167           (forward-char 1))))
 168       result)))
 169
 170 (defun ietf-drums-strip (string)
 171   "Remove comments and whitespace from STRING."
 172   (ietf-drums-remove-whitespace (ietf-drums-remove-comments string)))
 173
 174 (defun ietf-drums-parse-address (string)
 175   "Parse STRING and return a MAILBOX / DISPLAY-NAME pair."
 176   (with-temp-buffer
 177     (let (display-name mailbox c display-string)
 178       (ietf-drums-init string)
 179       (while (not (eobp))
 180         (setq c (char-after))
 181         (cond
 182          ((or (eq c ? )
 183               (eq c ?\t))
 184           (forward-char 1))
 185          ((eq c ?\()
 186           (forward-sexp 1))
 187          ((eq c ?\")
 188           (push (buffer-substring
 189                  (1+ (point)) (progn (forward-sexp 1) (1- (point))))
 190                 display-name))
 191          ((looking-at (concat "[" ietf-drums-atext-token "@" "]"))
 192           (push (buffer-substring (point) (progn (forward-sexp 1) (point)))
 193                 display-name))
 194          ((eq c ?<)
 195           (setq mailbox
 196                 (ietf-drums-remove-whitespace
 197                  (ietf-drums-remove-comments
 198                   (buffer-substring
 199                    (1+ (point))
 200                    (progn (forward-sexp 1) (1- (point))))))))
 201          (t
 202           (message "Unknown symbol: %c" c)
 203           (forward-char 1))))
 204       ;; If we found no display-name, then we look for comments.
 205       (if display-name
 206           (setq display-string
 207                 (mapconcat 'identity (reverse display-name) " "))
 208         (setq display-string (ietf-drums-get-comment string)))
 209       (if (not mailbox)
 210           (when (string-match "@" display-string)
 211             (cons
 212              (mapconcat 'identity (nreverse display-name) "")
 213              (ietf-drums-get-comment string)))
 214         (cons mailbox display-string)))))
 215
 216 (defun ietf-drums-parse-addresses (string &optional rawp)
 217   "Parse STRING and return a list of MAILBOX / DISPLAY-NAME pairs.
 218 If RAWP, don't actually parse the addresses, but instead return
 219 a list of address strings."
 220   (if (null string)
 221       nil
 222     (with-temp-buffer
 223       (ietf-drums-init string)
 224       (let ((beg (point))
 225             pairs c address)
 226         (while (not (eobp))
 227           (setq c (char-after))
 228           (cond
 229            ((memq c '(?\" ?< ?\())
 230             (condition-case nil
 231                 (forward-sexp 1)
 232               (error
 233                (skip-chars-forward "^,"))))
 234            ((eq c ?,)
 235             (setq address
 236                   (if rawp
 237                       (buffer-substring beg (point))
 238                     (condition-case nil
 239                         (ietf-drums-parse-address
 240                          (buffer-substring beg (point)))
 241                       (error nil))))
 242             (if address (push address pairs))
 243             (forward-char 1)
 244             (setq beg (point)))
 245            (t
 246             (forward-char 1))))
 247         (setq address
 248               (if rawp
 249                   (buffer-substring beg (point))
 250                 (condition-case nil
 251                     (ietf-drums-parse-address
 252                      (buffer-substring beg (point)))
 253                   (error nil))))
 254         (if address (push address pairs))
 255         (nreverse pairs)))))
 256
 257 (defun ietf-drums-unfold-fws ()
 258   "Unfold folding white space in the current buffer."
 259   (goto-char (point-min))
 260   (while (re-search-forward ietf-drums-fws-regexp nil t)
 261     (replace-match " " t t))
 262   (goto-char (point-min)))
 263
 264 (defun ietf-drums-parse-date (string)
 265   "Return an Emacs time spec from STRING."
 266   (apply 'encode-time (parse-time-string string)))
 267
 268 (defun ietf-drums-narrow-to-header ()
 269   "Narrow to the header section in the current buffer."
 270   (narrow-to-region
 271    (goto-char (point-min))
 272    (if (re-search-forward "^\r?$" nil 1)
 273        (match-beginning 0)
 274      (point-max)))
 275   (goto-char (point-min)))
 276
 277 (defun ietf-drums-quote-string (string)
 278   "Quote string if it needs quoting to be displayed in a header."
 279   (if (string-match (concat "[^" ietf-drums-atext-token "]") string)
 280       (concat "\"" string "\"")
 281     string))
 282
 283 (defun ietf-drums-make-address (name address)
 284   (if name
 285       (concat (ietf-drums-quote-string name) " <" address ">")
 286     address))
 287
 288 (provide 'ietf-drums)
 289
 290 ;; arch-tag: 379a0191-dbae-4ca6-a0f5-d4202c209ef9
 291 ;;; ietf-drums.el ends here