code.delx.au - gnu-emacs/blob - 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 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 2, or (at your option)
  12 ;; 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; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22 ;; Boston, MA 02110-1301, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; DRUMS is an IETF Working Group that works (or worked) on the
  27 ;; successor to RFC822, "Standard For The Format Of Arpa Internet Text
  28 ;; Messages".  This library is based on
  29 ;; draft-ietf-drums-msg-fmt-05.txt, released on 1998-08-05.
  30
  31 ;; Pending a real regression self test suite, Simon Josefsson added
  32 ;; various self test expressions snipped from bug reports, and their
  33 ;; expected value, below.  I you believe it could be useful, please
  34 ;; add your own test cases, or write a real self test suite, or just
  35 ;; remove this.
  36
  37 ;; <m3oekvfd50.fsf@whitebox.m5r.de>
  38 ;; (ietf-drums-parse-address "'foo' <foo@example.com>")
  39 ;; => ("foo@example.com" . "'foo'")
  40
  41 ;;; Code:
  42
  43 (eval-when-compile (require 'cl))
  44 (require 'time-date)
  45 (require 'mm-util)
  46
  47 (defvar ietf-drums-no-ws-ctl-token "\001-\010\013\014\016-\037\177"
  48   "US-ASCII control characters excluding CR, LF and white space.")
  49 (defvar ietf-drums-text-token "\001-\011\013\014\016-\177"
  50   "US-ASCII characters excluding CR and LF.")
  51 (defvar ietf-drums-specials-token "()<>[]:;@\\,.\""
  52   "Special characters.")
  53 (defvar ietf-drums-quote-token "\\"
  54   "Quote character.")
  55 (defvar ietf-drums-wsp-token " \t"
  56   "White space.")
  57 (defvar ietf-drums-fws-regexp
  58   (concat "[" ietf-drums-wsp-token "]*\n[" ietf-drums-wsp-token "]+")
  59   "Folding white space.")
  60 (defvar ietf-drums-atext-token "-^a-zA-Z0-9!#$%&'*+/=?_`{|}~"
  61   "Textual token.")
  62 (defvar ietf-drums-dot-atext-token "-^a-zA-Z0-9!#$%&'*+/=?_`{|}~."
  63   "Textual token including full stop.")
  64 (defvar ietf-drums-qtext-token
  65   (concat ietf-drums-no-ws-ctl-token "\041\043-\133\135-\177")
  66   "Non-white-space control characters, plus the rest of ASCII excluding
  67 backslash and doublequote.")
  68 (defvar ietf-drums-tspecials "][()<>@,;:\\\"/?="
  69   "Tspecials.")
  70
  71 (defvar ietf-drums-syntax-table
  72   (let ((table (copy-syntax-table emacs-lisp-mode-syntax-table)))
  73     (modify-syntax-entry ?\\ "/" table)
  74     (modify-syntax-entry ?< "(" table)
  75     (modify-syntax-entry ?> ")" table)
  76     (modify-syntax-entry ?@ "w" table)
  77     (modify-syntax-entry ?/ "w" table)
  78     (modify-syntax-entry ?* "_" table)
  79     (modify-syntax-entry ?\; "_" table)
  80     (modify-syntax-entry ?\' "_" table)
  81     (if (featurep 'xemacs)
  82         (let ((i 128))
  83           (while (< i 256)
  84             (modify-syntax-entry i "w" table)
  85             (setq i (1+ i)))))
  86     table))
  87
  88 (defun ietf-drums-token-to-list (token)
  89   "Translate TOKEN into a list of characters."
  90   (let ((i 0)
  91         b e c out range)
  92     (while (< i (length token))
  93       (setq c (mm-char-int (aref token i)))
  94       (incf i)
  95       (cond
  96        ((eq c (mm-char-int ?-))
  97         (if b
  98             (setq range t)
  99           (push c out)))
 100        (range
 101         (while (<= b c)
 102           (push (mm-make-char 'ascii b) out)
 103           (incf b))
 104         (setq range nil))
 105        ((= i (length token))
 106         (push (mm-make-char 'ascii c) out))
 107        (t
 108         (when b
 109           (push (mm-make-char 'ascii b) out))
 110         (setq b c))))
 111     (nreverse out)))
 112
 113 (defsubst ietf-drums-init (string)
 114   (set-syntax-table ietf-drums-syntax-table)
 115   (insert string)
 116   (ietf-drums-unfold-fws)
 117   (goto-char (point-min)))
 118
 119 (defun ietf-drums-remove-comments (string)
 120   "Remove comments from STRING."
 121   (with-temp-buffer
 122     (let (c)
 123       (ietf-drums-init string)
 124       (while (not (eobp))
 125         (setq c (char-after))
 126         (cond
 127          ((eq c ?\")
 128           (forward-sexp 1))
 129          ((eq c ?\()
 130           (delete-region (point) (progn (forward-sexp 1) (point))))
 131          (t
 132           (forward-char 1))))
 133       (buffer-string))))
 134
 135 (defun ietf-drums-remove-whitespace (string)
 136   "Remove whitespace from STRING."
 137   (with-temp-buffer
 138     (ietf-drums-init string)
 139     (let (c)
 140       (while (not (eobp))
 141         (setq c (char-after))
 142         (cond
 143          ((eq c ?\")
 144           (forward-sexp 1))
 145          ((eq c ?\()
 146           (forward-sexp 1))
 147          ((memq c '(?\  ?\t ?\n))
 148           (delete-char 1))
 149          (t
 150           (forward-char 1))))
 151       (buffer-string))))
 152
 153 (defun ietf-drums-get-comment (string)
 154   "Return the first comment in STRING."
 155   (with-temp-buffer
 156     (ietf-drums-init string)
 157     (let (result c)
 158       (while (not (eobp))
 159         (setq c (char-after))
 160         (cond
 161          ((eq c ?\")
 162           (forward-sexp 1))
 163          ((eq c ?\()
 164           (setq result
 165                 (buffer-substring
 166                  (1+ (point))
 167                  (progn (forward-sexp 1) (1- (point))))))
 168          (t
 169           (forward-char 1))))
 170       result)))
 171
 172 (defun ietf-drums-strip (string)
 173   "Remove comments and whitespace from STRING."
 174   (ietf-drums-remove-whitespace (ietf-drums-remove-comments string)))
 175
 176 (defun ietf-drums-parse-address (string)
 177   "Parse STRING and return a MAILBOX / DISPLAY-NAME pair."
 178   (with-temp-buffer
 179     (let (display-name mailbox c display-string)
 180       (ietf-drums-init string)
 181       (while (not (eobp))
 182         (setq c (char-after))
 183         (cond
 184          ((or (eq c ? )
 185               (eq c ?\t))
 186           (forward-char 1))
 187          ((eq c ?\()
 188           (forward-sexp 1))
 189          ((eq c ?\")
 190           (push (buffer-substring
 191                  (1+ (point)) (progn (forward-sexp 1) (1- (point))))
 192                 display-name))
 193          ((looking-at (concat "[" ietf-drums-atext-token "@" "]"))
 194           (push (buffer-substring (point) (progn (forward-sexp 1) (point)))
 195                 display-name))
 196          ((eq c ?<)
 197           (setq mailbox
 198                 (ietf-drums-remove-whitespace
 199                  (ietf-drums-remove-comments
 200                   (buffer-substring
 201                    (1+ (point))
 202                    (progn (forward-sexp 1) (1- (point))))))))
 203          (t (error "Unknown symbol: %c" c))))
 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)
 217   "Parse STRING and return a list of MAILBOX / DISPLAY-NAME pairs."
 218   (if (null string)
 219       nil
 220     (with-temp-buffer
 221       (ietf-drums-init string)
 222       (let ((beg (point))
 223             pairs c address)
 224         (while (not (eobp))
 225           (setq c (char-after))
 226           (cond
 227            ((memq c '(?\" ?< ?\())
 228             (condition-case nil
 229                 (forward-sexp 1)
 230               (error
 231                (skip-chars-forward "^,"))))
 232            ((eq c ?,)
 233             (setq address
 234                   (condition-case nil
 235                       (ietf-drums-parse-address
 236                        (buffer-substring beg (point)))
 237                     (error nil)))
 238             (if address (push address pairs))
 239             (forward-char 1)
 240             (setq beg (point)))
 241            (t
 242             (forward-char 1))))
 243         (setq address
 244               (condition-case nil
 245                   (ietf-drums-parse-address
 246                    (buffer-substring beg (point)))
 247                 (error nil)))
 248         (if address (push address pairs))
 249         (nreverse pairs)))))
 250
 251 (defun ietf-drums-unfold-fws ()
 252   "Unfold folding white space in the current buffer."
 253   (goto-char (point-min))
 254   (while (re-search-forward ietf-drums-fws-regexp nil t)
 255     (replace-match " " t t))
 256   (goto-char (point-min)))
 257
 258 (defun ietf-drums-parse-date (string)
 259   "Return an Emacs time spec from STRING."
 260   (apply 'encode-time (parse-time-string string)))
 261
 262 (defun ietf-drums-narrow-to-header ()
 263   "Narrow to the header section in the current buffer."
 264   (narrow-to-region
 265    (goto-char (point-min))
 266    (if (re-search-forward "^\r?$" nil 1)
 267        (match-beginning 0)
 268      (point-max)))
 269   (goto-char (point-min)))
 270
 271 (defun ietf-drums-quote-string (string)
 272   "Quote string if it needs quoting to be displayed in a header."
 273   (if (string-match (concat "[^" ietf-drums-atext-token "]") string)
 274       (concat "\"" string "\"")
 275     string))
 276
 277 (provide 'ietf-drums)
 278
 279 ;;; arch-tag: 379a0191-dbae-4ca6-a0f5-d4202c209ef9
 280 ;;; ietf-drums.el ends here