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, 2009, 2010 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           (condition-case err
 127               (forward-sexp 1)
 128             (error (goto-char (point-max)))))
 129          ((eq c ?\()
 130           (delete-region
 131                (point)
 132                (condition-case nil
 133                    (with-syntax-table (copy-syntax-table ietf-drums-syntax-table)
 134                      (modify-syntax-entry ?\" "w")
 135                      (forward-sexp 1)
 136                      (point))
 137                  (error (point-max)))))
 138          (t
 139           (forward-char 1))))
 140       (buffer-string))))
 141
 142 (defun ietf-drums-remove-whitespace (string)
 143   "Remove whitespace from STRING."
 144   (with-temp-buffer
 145     (ietf-drums-init string)
 146     (let (c)
 147       (while (not (eobp))
 148         (setq c (char-after))
 149         (cond
 150          ((eq c ?\")
 151           (forward-sexp 1))
 152          ((eq c ?\()
 153           (forward-sexp 1))
 154          ((memq c '(?\  ?\t ?\n))
 155           (delete-char 1))
 156          (t
 157           (forward-char 1))))
 158       (buffer-string))))
 159
 160 (defun ietf-drums-get-comment (string)
 161   "Return the first comment in STRING."
 162   (with-temp-buffer
 163     (ietf-drums-init string)
 164     (let (result c)
 165       (while (not (eobp))
 166         (setq c (char-after))
 167         (cond
 168          ((eq c ?\")
 169           (forward-sexp 1))
 170          ((eq c ?\()
 171           (setq result
 172                 (buffer-substring
 173                  (1+ (point))
 174                  (progn (forward-sexp 1) (1- (point))))))
 175          (t
 176           (forward-char 1))))
 177       result)))
 178
 179 (defun ietf-drums-strip (string)
 180   "Remove comments and whitespace from STRING."
 181   (ietf-drums-remove-whitespace (ietf-drums-remove-comments string)))
 182
 183 (defun ietf-drums-parse-address (string)
 184   "Parse STRING and return a MAILBOX / DISPLAY-NAME pair."
 185   (with-temp-buffer
 186     (let (display-name mailbox c display-string)
 187       (ietf-drums-init string)
 188       (while (not (eobp))
 189         (setq c (char-after))
 190         (cond
 191          ((or (eq c ? )
 192               (eq c ?\t))
 193           (forward-char 1))
 194          ((eq c ?\()
 195           (forward-sexp 1))
 196          ((eq c ?\")
 197           (push (buffer-substring
 198                  (1+ (point)) (progn (forward-sexp 1) (1- (point))))
 199                 display-name))
 200          ((looking-at (concat "[" ietf-drums-atext-token "@" "]"))
 201           (push (buffer-substring (point) (progn (forward-sexp 1) (point)))
 202                 display-name))
 203          ((eq c ?<)
 204           (setq mailbox
 205                 (ietf-drums-remove-whitespace
 206                  (ietf-drums-remove-comments
 207                   (buffer-substring
 208                    (1+ (point))
 209                    (progn (forward-sexp 1) (1- (point))))))))
 210          (t
 211           (message "Unknown symbol: %c" c)
 212           (forward-char 1))))
 213       ;; If we found no display-name, then we look for comments.
 214       (if display-name
 215           (setq display-string
 216                 (mapconcat 'identity (reverse display-name) " "))
 217         (setq display-string (ietf-drums-get-comment string)))
 218       (if (not mailbox)
 219           (when (string-match "@" display-string)
 220             (cons
 221              (mapconcat 'identity (nreverse display-name) "")
 222              (ietf-drums-get-comment string)))
 223         (cons mailbox display-string)))))
 224
 225 (defun ietf-drums-parse-addresses (string &optional rawp)
 226   "Parse STRING and return a list of MAILBOX / DISPLAY-NAME pairs.
 227 If RAWP, don't actually parse the addresses, but instead return
 228 a list of address strings."
 229   (if (null string)
 230       nil
 231     (with-temp-buffer
 232       (ietf-drums-init string)
 233       (let ((beg (point))
 234             pairs c address)
 235         (while (not (eobp))
 236           (setq c (char-after))
 237           (cond
 238            ((memq c '(?\" ?< ?\())
 239             (condition-case nil
 240                 (forward-sexp 1)
 241               (error
 242                (skip-chars-forward "^,"))))
 243            ((eq c ?,)
 244             (setq address
 245                   (if rawp
 246                       (buffer-substring beg (point))
 247                     (condition-case nil
 248                         (ietf-drums-parse-address
 249                          (buffer-substring beg (point)))
 250                       (error nil))))
 251             (if address (push address pairs))
 252             (forward-char 1)
 253             (setq beg (point)))
 254            (t
 255             (forward-char 1))))
 256         (setq address
 257               (if rawp
 258                   (buffer-substring beg (point))
 259                 (condition-case nil
 260                     (ietf-drums-parse-address
 261                      (buffer-substring beg (point)))
 262                   (error nil))))
 263         (if address (push address pairs))
 264         (nreverse pairs)))))
 265
 266 (defun ietf-drums-unfold-fws ()
 267   "Unfold folding white space in the current buffer."
 268   (goto-char (point-min))
 269   (while (re-search-forward ietf-drums-fws-regexp nil t)
 270     (replace-match " " t t))
 271   (goto-char (point-min)))
 272
 273 (defun ietf-drums-parse-date (string)
 274   "Return an Emacs time spec from STRING."
 275   (apply 'encode-time (parse-time-string string)))
 276
 277 (defun ietf-drums-narrow-to-header ()
 278   "Narrow to the header section in the current buffer."
 279   (narrow-to-region
 280    (goto-char (point-min))
 281    (if (re-search-forward "^\r?$" nil 1)
 282        (match-beginning 0)
 283      (point-max)))
 284   (goto-char (point-min)))
 285
 286 (defun ietf-drums-quote-string (string)
 287   "Quote string if it needs quoting to be displayed in a header."
 288   (if (string-match (concat "[^" ietf-drums-atext-token "]") string)
 289       (concat "\"" string "\"")
 290     string))
 291
 292 (defun ietf-drums-make-address (name address)
 293   (if name
 294       (concat (ietf-drums-quote-string name) " <" address ">")
 295     address))
 296
 297 (provide 'ietf-drums)
 298
 299 ;; arch-tag: 379a0191-dbae-4ca6-a0f5-d4202c209ef9
 300 ;;; ietf-drums.el ends here