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emacs/lisp/gnus/ietf-drums.el
2003-09-01 15:45:59 +00:00

253 lines
7.3 KiB
EmacsLisp

;;; ietf-drums.el --- functions for parsing RFC822bis headers
;; Copyright (C) 1998, 1999, 2000, 2002
;; Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Commentary:
;; DRUMS is an IETF Working Group that works (or worked) on the
;; successor to RFC822, "Standard For The Format Of Arpa Internet Text
;; Messages". This library is based on
;; draft-ietf-drums-msg-fmt-05.txt, released on 1998-08-05.
;;; Code:
(eval-when-compile (require 'cl))
(require 'time-date)
(require 'mm-util)
(defvar ietf-drums-no-ws-ctl-token "\001-\010\013\014\016-\037\177"
"US-ASCII control characters excluding CR, LF and white space.")
(defvar ietf-drums-text-token "\001-\011\013\014\016-\177"
"US-ASCII characters excluding CR and LF.")
(defvar ietf-drums-specials-token "()<>[]:;@\\,.\""
"Special characters.")
(defvar ietf-drums-quote-token "\\"
"Quote character.")
(defvar ietf-drums-wsp-token " \t"
"White space.")
(defvar ietf-drums-fws-regexp
(concat "[" ietf-drums-wsp-token "]*\n[" ietf-drums-wsp-token "]+")
"Folding white space.")
(defvar ietf-drums-atext-token "-^a-zA-Z0-9!#$%&'*+/=?_`{|}~"
"Textual token.")
(defvar ietf-drums-dot-atext-token "-^a-zA-Z0-9!#$%&'*+/=?_`{|}~."
"Textual token including full stop.")
(defvar ietf-drums-qtext-token
(concat ietf-drums-no-ws-ctl-token "\041\043-\133\135-\177")
"Non-white-space control characters, plus the rest of ASCII excluding
backslash and doublequote.")
(defvar ietf-drums-tspecials "][()<>@,;:\\\"/?="
"Tspecials.")
(defvar ietf-drums-syntax-table
(let ((table (copy-syntax-table emacs-lisp-mode-syntax-table)))
(modify-syntax-entry ?\\ "/" table)
(modify-syntax-entry ?< "(" table)
(modify-syntax-entry ?> ")" table)
(modify-syntax-entry ?@ "w" table)
(modify-syntax-entry ?/ "w" table)
(modify-syntax-entry ?= " " table)
(modify-syntax-entry ?* " " table)
(modify-syntax-entry ?\; " " table)
(modify-syntax-entry ?\' " " table)
table))
(defun ietf-drums-token-to-list (token)
"Translate TOKEN into a list of characters."
(let ((i 0)
b e c out range)
(while (< i (length token))
(setq c (mm-char-int (aref token i)))
(incf i)
(cond
((eq c (mm-char-int ?-))
(if b
(setq range t)
(push c out)))
(range
(while (<= b c)
(push (mm-make-char 'ascii b) out)
(incf b))
(setq range nil))
((= i (length token))
(push (mm-make-char 'ascii c) out))
(t
(when b
(push (mm-make-char 'ascii b) out))
(setq b c))))
(nreverse out)))
(defsubst ietf-drums-init (string)
(set-syntax-table ietf-drums-syntax-table)
(insert string)
(ietf-drums-unfold-fws)
(goto-char (point-min)))
(defun ietf-drums-remove-comments (string)
"Remove comments from STRING."
(with-temp-buffer
(let (c)
(ietf-drums-init string)
(while (not (eobp))
(setq c (char-after))
(cond
((eq c ?\")
(forward-sexp 1))
((eq c ?\()
(delete-region (point) (progn (forward-sexp 1) (point))))
(t
(forward-char 1))))
(buffer-string))))
(defun ietf-drums-remove-whitespace (string)
"Remove whitespace from STRING."
(with-temp-buffer
(ietf-drums-init string)
(let (c)
(while (not (eobp))
(setq c (char-after))
(cond
((eq c ?\")
(forward-sexp 1))
((eq c ?\()
(forward-sexp 1))
((memq c '(?\ ?\t ?\n))
(delete-char 1))
(t
(forward-char 1))))
(buffer-string))))
(defun ietf-drums-get-comment (string)
"Return the first comment in STRING."
(with-temp-buffer
(ietf-drums-init string)
(let (result c)
(while (not (eobp))
(setq c (char-after))
(cond
((eq c ?\")
(forward-sexp 1))
((eq c ?\()
(setq result
(buffer-substring
(1+ (point))
(progn (forward-sexp 1) (1- (point))))))
(t
(forward-char 1))))
result)))
(defun ietf-drums-strip (string)
"Remove comments and whitespace from STRING."
(ietf-drums-remove-whitespace (ietf-drums-remove-comments string)))
(defun ietf-drums-parse-address (string)
"Parse STRING and return a MAILBOX / DISPLAY-NAME pair."
(with-temp-buffer
(let (display-name mailbox c display-string)
(ietf-drums-init string)
(while (not (eobp))
(setq c (char-after))
(cond
((or (eq c ? )
(eq c ?\t))
(forward-char 1))
((eq c ?\()
(forward-sexp 1))
((eq c ?\")
(push (buffer-substring
(1+ (point)) (progn (forward-sexp 1) (1- (point))))
display-name))
((looking-at (concat "[" ietf-drums-atext-token "@" "]"))
(push (buffer-substring (point) (progn (forward-sexp 1) (point)))
display-name))
((eq c ?<)
(setq mailbox
(ietf-drums-remove-whitespace
(ietf-drums-remove-comments
(buffer-substring
(1+ (point))
(progn (forward-sexp 1) (1- (point))))))))
(t (error "Unknown symbol: %c" c))))
;; If we found no display-name, then we look for comments.
(if display-name
(setq display-string
(mapconcat 'identity (reverse display-name) " "))
(setq display-string (ietf-drums-get-comment string)))
(if (not mailbox)
(when (string-match "@" display-string)
(cons
(mapconcat 'identity (nreverse display-name) "")
(ietf-drums-get-comment string)))
(cons mailbox display-string)))))
(defun ietf-drums-parse-addresses (string)
"Parse STRING and return a list of MAILBOX / DISPLAY-NAME pairs."
(with-temp-buffer
(ietf-drums-init string)
(let ((beg (point))
pairs c)
(while (not (eobp))
(setq c (char-after))
(cond
((memq c '(?\" ?< ?\())
(forward-sexp 1))
((eq c ?,)
(push (ietf-drums-parse-address (buffer-substring beg (point)))
pairs)
(forward-char 1)
(setq beg (point)))
(t
(forward-char 1))))
(push (ietf-drums-parse-address (buffer-substring beg (point)))
pairs)
(nreverse pairs))))
(defun ietf-drums-unfold-fws ()
"Unfold folding white space in the current buffer."
(goto-char (point-min))
(while (re-search-forward ietf-drums-fws-regexp nil t)
(replace-match " " t t))
(goto-char (point-min)))
(defun ietf-drums-parse-date (string)
"Return an Emacs time spec from STRING."
(apply 'encode-time (parse-time-string string)))
(defun ietf-drums-narrow-to-header ()
"Narrow to the header section in the current buffer."
(narrow-to-region
(goto-char (point-min))
(if (re-search-forward "^\r?$" nil 1)
(match-beginning 0)
(point-max)))
(goto-char (point-min)))
(defun ietf-drums-quote-string (string)
"Quote string if it needs quoting to be displayed in a header."
(if (string-match (concat "[^" ietf-drums-atext-token "]") string)
(concat "\"" string "\"")
string))
(provide 'ietf-drums)
;;; arch-tag: 379a0191-dbae-4ca6-a0f5-d4202c209ef9
;;; ietf-drums.el ends here