[Emacs-diffs] Changes to emacs/lisp/international/mule.el

[Colin Walters]

Index: emacs/lisp/international/mule.el
diff -c emacs/lisp/international/mule.el:1.143 
emacs/lisp/international/mule.el:1.144
*** emacs/lisp/international/mule.el:1.143      Mon May 20 10:13:10 2002
--- emacs/lisp/international/mule.el    Tue May 21 17:14:03 2002
***************
*** 725,733 ****
  
  TYPE is an integer value indicating the type of the coding system as follows:
    0: Emacs internal format,
!   1: Shift-JIS (or MS-Kanji) used mainly on Japanese PC,
    2: ISO-2022 including many variants,
!   3: Big5 used mainly on Chinese PC,
    4: private, CCL programs provide encoding/decoding algorithm,
    5: Raw-text, which means that text contains random 8-bit codes.
  
--- 725,733 ----
  
  TYPE is an integer value indicating the type of the coding system as follows:
    0: Emacs internal format,
!   1: Shift-JIS (or MS-Kanji) used mainly on Japanese PCs,
    2: ISO-2022 including many variants,
!   3: Big5 used mainly on Chinese PCs,
    4: private, CCL programs provide encoding/decoding algorithm,
    5: Raw-text, which means that text contains random 8-bit codes.
  
***************
*** 822,828 ****
   
    o mime-charset
   
!   The value is a symbol of which name is `MIME-charset' parameter of
    the coding system.
   
    o valid-codes (meaningful only for a coding system based on CCL)
--- 822,828 ----
   
    o mime-charset
   
!   The value is a symbol whose name is the `MIME-charset' parameter of
    the coding system.
   
    o valid-codes (meaningful only for a coding system based on CCL)
***************
*** 1489,1494 ****
--- 1489,1510 ----
    :type '(repeat (cons (regexp :tag "Regexp")
                       (symbol :tag "Coding system"))))
  
+ ;; See the bottom of this file for built-in auto coding functions.
+ (defcustom auto-coding-functions '(sgml-xml-auto-coding-function)
+   "A list of functions which attempt to determine a coding system.
+ 
+ Each function in this list should be written to operate on the current
+ buffer, but should not modify it in any way.  It should take one
+ argument SIZE, past which it should not search.  If a function
+ succeeds in determining a coding system, it should return that coding
+ system.  Otherwise, it should return nil.
+ 
+ The functions in this list take priority over `coding:' tags in the
+ file, just as for `auto-coding-regexp-alist'."
+   :group 'files
+   :group 'mule
+   :type '(repeat function))
+ 
  (defvar set-auto-coding-for-load nil
    "Non-nil means look for `load-coding' property instead of `coding'.
  This is used for loading and byte-compiling Emacs Lisp files.")
***************
*** 1504,1524 ****
        (setq alist (cdr alist))))
      coding-system))
  
- 
  (defun auto-coding-from-file-contents (size)
    "Determine a coding system from the contents of the current buffer.
  The current buffer contains SIZE bytes starting at point.
  Value is either a coding system or nil."
    (save-excursion
      (let ((alist auto-coding-regexp-alist)
          coding-system)
        (while (and alist (not coding-system))
        (let ((regexp (car (car alist))))
          (when (re-search-forward regexp (+ (point) size) t)
            (setq coding-system (cdr (car alist)))))
        (setq alist (cdr alist)))
        coding-system)))
-               
  
  (defun set-auto-coding (filename size)
    "Return coding system for a file FILENAME of which SIZE bytes follow point.
--- 1520,1544 ----
        (setq alist (cdr alist))))
      coding-system))
  
  (defun auto-coding-from-file-contents (size)
    "Determine a coding system from the contents of the current buffer.
  The current buffer contains SIZE bytes starting at point.
  Value is either a coding system or nil."
    (save-excursion
      (let ((alist auto-coding-regexp-alist)
+         (funcs auto-coding-functions)
          coding-system)
        (while (and alist (not coding-system))
        (let ((regexp (car (car alist))))
          (when (re-search-forward regexp (+ (point) size) t)
            (setq coding-system (cdr (car alist)))))
        (setq alist (cdr alist)))
+       (while (and funcs (not coding-system))
+       (setq coding-system (condition-case e
+                               (save-excursion
+                                 (funcall (pop funcs) size))
+                             (error nil))))
        coding-system)))
  
  (defun set-auto-coding (filename size)
    "Return coding system for a file FILENAME of which SIZE bytes follow point.
***************
*** 1528,1534 ****
  It checks FILENAME against the variable `auto-coding-alist'.  If
  FILENAME doesn't match any entries in the variable, it checks the
  contents of the current buffer following point against
! `auto-coding-regexp-alist'.  If no match is found, it checks for a
  `coding:' tag in the first one or two lines following point.  If no
  `coding:' tag is found, it checks for local variables list in the last
  3K bytes out of the SIZE bytes.
--- 1548,1555 ----
  It checks FILENAME against the variable `auto-coding-alist'.  If
  FILENAME doesn't match any entries in the variable, it checks the
  contents of the current buffer following point against
! `auto-coding-regexp-alist', and tries calling each function in
! `auto-coding-functions'.  If no match is found, it checks for a
  `coding:' tag in the first one or two lines following point.  If no
  `coding:' tag is found, it checks for local variables list in the last
  3K bytes out of the SIZE bytes.
***************
*** 1897,1902 ****
--- 1918,1945 ----
  (put 'ignore-relative-composition 'char-table-extra-slots 0)
  (setq ignore-relative-composition
        (make-char-table 'ignore-relative-composition))
+ 
+ 
+ ;;; Built-in auto-coding-functions:
+ 
+ (defun sgml-xml-auto-coding-function (size)
+   "Determine whether the buffer is XML, and if so, its encoding.
+ This function is intended to be added to `auto-coding-functions'."
+   (when (re-search-forward "\\`[[:space:]\n]*<\\?xml")
+     (let ((end (save-excursion
+                ;; This is a hack.
+                (search-forward "\"\\s-*?>" size t))))
+       (when end
+       (if (re-search-forward "encoding=\"\\(.+?\\)\"" end t)
+           (let ((match (downcase (match-string 1))))
+             ;; FIXME: what other encodings are valid, and how can we
+             ;; translate them to the names of coding systems?
+             (cond ((string= match "utf-8")
+                    'utf-8)
+                   ((string-match "iso-8859-[[:digit:]]+" match)
+                    (intern match))
+                   (t nil)))
+         'utf-8)))))
  
  ;;;
  (provide 'mule)