1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
;;; nxml-enc.el --- XML encoding auto-detection
;; Copyright (C) 2003, 2007, 2008, 2009 Free Software Foundation, Inc.
;; Author: James Clark
;; Keywords: XML
;; 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 3 of the License, 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. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; User entry points are nxml-start-auto-coding and
;; nxml-stop-auto-coding. This is separate from nxml-mode, because
;; this cannot be autoloaded. It may use
;; `xmltok-get-declared-encoding-position' which can be autoloaded.
;; It's separate from rng-auto.el so it can be byte-compiled, and
;; because it provides independent, useful functionality.
;;; Code:
(defvar nxml-file-name-ignore-case
(memq system-type '(windows-nt)))
(defvar nxml-cached-file-name-auto-coding-regexp nil)
(defvar nxml-cached-auto-mode-alist nil)
(defun nxml-file-name-auto-coding-regexp ()
"Return regexp for filenames for which XML auto-coding should be done."
(if (eq auto-mode-alist nxml-cached-auto-mode-alist)
nxml-cached-file-name-auto-coding-regexp
(let ((alist auto-mode-alist)
(case-fold-search nxml-file-name-ignore-case)
regexps)
(setq nxml-cached-auto-mode-alist alist)
(while alist
(when (eq (cdar alist) 'nxml-mode)
(setq regexps (cons (caar alist) regexps)))
(setq alist (cdr alist)))
(setq nxml-cached-file-name-auto-coding-regexp
(if (null (cdr regexps))
(car regexps)
(mapconcat (lambda (r)
(concat "\\(?:" r "\\)"))
regexps
"\\|"))))))
(defvar nxml-non-xml-set-auto-coding-function nil
"The function that `set-auto-coding-function' should call for non-XML files.")
(defun nxml-set-auto-coding (file-name size)
(if (let ((case-fold-search nxml-file-name-ignore-case)
(regexp (nxml-file-name-auto-coding-regexp)))
(and regexp
(string-match regexp file-name)))
(nxml-set-xml-coding file-name size)
(and nxml-non-xml-set-auto-coding-function
(funcall nxml-non-xml-set-auto-coding-function file-name size))))
(defun nxml-set-xml-coding (file-name size)
"Function to use as `set-auto-coding-function' when file is known to be XML."
(nxml-detect-coding-system (+ (point) (min size 1024))))
(declare-function xmltok-get-declared-encoding-position "xmltok"
(&optional limit)) ; autoloaded
(defun nxml-detect-coding-system (limit)
(if (< limit (+ (point) 2))
(if (eq (char-after) 0) 'no-conversion 'utf-8)
(let ((first-two-chars (list (char-after)
(char-after (1+ (point))))))
(cond ((equal first-two-chars '(#xFE #xFF))
(and (coding-system-p 'utf-16-be) 'utf-16-be))
((equal first-two-chars '(#xFF #xFE))
(and (coding-system-p 'utf-16-le) 'utf-16-le))
((memq 0 first-two-chars)
;; Certainly not well-formed XML;
;; perhaps UTF-16 without BOM.
;; In any case, we can't handle it.
;; no-conversion gives the user a chance to fix it.
'no-conversion)
;; There are other things we might try here in the future
;; eg UTF-8 BOM, UTF-16 with no BOM
;; translate to EBCDIC
(t
(let ((enc-pos (xmltok-get-declared-encoding-position limit)))
(cond ((consp enc-pos)
(or (nxml-mime-charset-coding-system
(buffer-substring-no-properties (car enc-pos)
(cdr enc-pos)))
;; We have an encoding whose name we don't recognize.
;; What to do?
;; raw-text seems the best bet: since we got
;; the XML decl it must be a superset of ASCII,
;; so we don't need to go to no-conversion
'raw-text))
(enc-pos 'utf-8)
;; invalid XML declaration
(t nil))))))))
(defun nxml-mime-charset-coding-system (charset)
(let ((charset-sym (intern (downcase charset)))
(coding-systems (coding-system-list t))
coding-system ret)
(while (and coding-systems (not ret))
(setq coding-system (car coding-systems))
(if (eq (coding-system-get coding-system 'mime-charset)
charset-sym)
(setq ret coding-system)
(setq coding-systems (cdr coding-systems))))
ret))
(defun nxml-start-auto-coding ()
"Do encoding auto-detection as specified in the XML standard.
Applied to any files that `auto-mode-alist' says should be handled by
`nxml-mode'."
(interactive)
(unless (eq set-auto-coding-function 'nxml-set-auto-coding)
(let ((inhibit-quit t))
(setq nxml-non-xml-set-auto-coding-function set-auto-coding-function)
(setq set-auto-coding-function 'nxml-set-auto-coding))))
(defun nxml-stop-auto-coding ()
"Stop doing encoding auto-detection as specified in the XML standard."
(interactive)
(when (eq set-auto-coding-function 'nxml-set-auto-coding)
(let ((inhibit-quit t))
(setq set-auto-coding-function nxml-non-xml-set-auto-coding-function)
(setq nxml-non-xml-set-auto-coding-function nil))))
;; Emacs 22 makes us-ascii an alias for iso-safe without
;; giving it a mime-charset property.
(unless (coding-system-get 'us-ascii 'mime-charset)
(coding-system-put 'us-ascii 'mime-charset 'us-ascii))
(provide 'nxml-enc)
;; arch-tag: c2436247-78f3-418c-8069-85dc5335d083
;;; nxml-enc.el ends here
|
