lisp/gnus/gnus-mule.el

   1 ;;; gnus-mule.el --- Provide backward compatibility function to GNUS
   2
   3 ;; Copyright (C) 1995,1997 Free Software Foundation, Inc.
   4 ;; Copyright (C) 1995, 2000 Electrotechnical Laboratory, JAPAN.
   5
   6 ;; Maintainer: FSF
   7 ;; Keywords: news, i18n
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; This file provides the function `gnus-mule-add-group' for backward
  29 ;; compatibility with old version of Gnus included in Emacs 20.
  30
  31 (require 'gnus-sum)
  32
  33 ;;;###autoload
  34 (defun gnus-mule-add-group (name coding-system)
  35   "Specify that articles of news group NAME are encoded in CODING-SYSTEM.
  36 All news groups deeper than NAME are also the target.
  37 If CODING-SYSTEM is a cons, the car part is used and the cdr
  38 part is ignored.
  39
  40 This function exists for backward comaptibility with Emacs 20.  It is
  41 recommended to customize the variable `gnus-group-charset-alist'
  42 rather than using this function."
  43   (if (consp coding-system)
  44       ;; Ignore the cdr part because now Gnus can't use different
  45       ;; coding systems for encoding and decoding.
  46       (setq coding-system (car coding-system)))
  47   (let ((tail gnus-group-charset-alist)
  48         (prev nil)
  49         (pattern (concat "^" (regexp-quote name))))
  50     ;; Check entries of `gnus-group-charset-alist' if they match NAME.
  51     (while (not (string-match (car (car tail)) name))
  52       (setq prev tail tail (cdr tail)))
  53     (if tail
  54         ;; A matching entry was found.
  55         (if (string= pattern (car (car tail)))
  56             ;; We can modify this entry.
  57             (setcar (cdr (car tail)) coding-system)
  58           ;; We must add a new entry before this.
  59           (if prev
  60               (setcdr prev (cons (list pattern coding-system)
  61                                  (cdr prev)))
  62             (setq gnus-group-charset-alist
  63                   (cons (list pattern coding-system)
  64                         gnus-group-charset-alist))))
  65       ;; We must prepend a new entry.
  66       (setq gnus-group-charset-alist
  67             (cons (list pattern coding-system)
  68                   gnus-group-charset-alist)))))
  69
  70 (provide 'gnus-mule)
  71
  72 ;; gnus-mule.el ends here