Line data Source code
1 : ;;; format.el --- read and save files in multiple formats
2 :
3 : ;; Copyright (C) 1994-1995, 1997, 1999, 2001-2017 Free Software
4 : ;; Foundation, Inc.
5 :
6 : ;; Author: Boris Goldowsky <boris@gnu.org>
7 : ;; Package: emacs
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 3 of the License, or
14 : ;; (at your option) 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. If not, see <http://www.gnu.org/licenses/>.
23 :
24 : ;;; Commentary:
25 :
26 : ;; This file defines a unified mechanism for saving & loading files stored
27 : ;; in different formats. `format-alist' contains information that directs
28 : ;; Emacs to call an encoding or decoding function when reading or writing
29 : ;; files that match certain conditions.
30 : ;;
31 : ;; When a file is visited, its format is determined by matching the
32 : ;; beginning of the file against regular expressions stored in
33 : ;; `format-alist'. If this fails, you can manually translate the buffer
34 : ;; using `format-decode-buffer'. In either case, the formats used are
35 : ;; listed in the variable `buffer-file-format', and become the default
36 : ;; format for saving the buffer. To save a buffer in a different format,
37 : ;; change this variable, or use `format-write-file'.
38 : ;;
39 : ;; Auto-save files are normally created in the same format as the visited
40 : ;; file, but the variable `buffer-auto-save-file-format' can be set to a
41 : ;; particularly fast or otherwise preferred format to be used for
42 : ;; auto-saving (or nil to do no encoding on auto-save files, but then you
43 : ;; risk losing any text-properties in the buffer).
44 : ;;
45 : ;; You can manually translate a buffer into or out of a particular format
46 : ;; with the functions `format-encode-buffer' and `format-decode-buffer'.
47 : ;; To translate just the region use the functions `format-encode-region'
48 : ;; and `format-decode-region'.
49 : ;;
50 : ;; You can define a new format by writing the encoding and decoding
51 : ;; functions, and adding an entry to `format-alist'. See enriched.el for
52 : ;; an example of how to implement a file format. There are various
53 : ;; functions defined in this file that may be useful for writing the
54 : ;; encoding and decoding functions:
55 : ;; * `format-annotate-region' and `format-deannotate-region' allow a
56 : ;; single alist of information to be used for encoding and decoding.
57 : ;; The alist defines a correspondence between strings in the file
58 : ;; ("annotations") and text-properties in the buffer.
59 : ;; * `format-replace-strings' is similarly useful for doing simple
60 : ;; string->string translations in a reversible manner.
61 :
62 : ;;; Code:
63 :
64 : (put 'buffer-file-format 'permanent-local t)
65 : (put 'buffer-auto-save-file-format 'permanent-local t)
66 :
67 : (defvar format-alist
68 : ;; FIXME: maybe each item can be purecopied instead of just the strings.
69 : `((text/enriched ,(purecopy "Extended MIME text/enriched format.")
70 : ,(purecopy "Content-[Tt]ype:[ \t]*text/enriched")
71 : enriched-decode enriched-encode t enriched-mode)
72 : (plain ,(purecopy "ISO 8859-1 standard format, no text properties.")
73 : ;; Plain only exists so that there is an obvious neutral choice in
74 : ;; the completion list.
75 : nil nil nil nil nil)
76 : (TeX ,(purecopy "TeX (encoding)")
77 : nil
78 : iso-tex2iso iso-iso2tex t nil)
79 : (gtex ,(purecopy "German TeX (encoding)")
80 : nil
81 : iso-gtex2iso iso-iso2gtex t nil)
82 : (html ,(purecopy "HTML/SGML \"ISO 8879:1986//ENTITIES Added Latin 1//EN\" (encoding)")
83 : nil
84 : iso-sgml2iso iso-iso2sgml t nil)
85 : (rot13 ,(purecopy "rot13")
86 : nil
87 : ,(purecopy "tr a-mn-z n-za-m") ,(purecopy "tr a-mn-z n-za-m") t nil)
88 : (duden ,(purecopy "Duden Ersatzdarstellung")
89 : nil
90 : ,(purecopy "diac") iso-iso2duden t nil)
91 : (de646 ,(purecopy "German ASCII (ISO 646)")
92 : nil
93 : ,(purecopy "recode -f iso646-ge:latin1")
94 : ,(purecopy "recode -f latin1:iso646-ge") t nil)
95 : (denet ,(purecopy "net German")
96 : nil
97 : iso-german iso-cvt-read-only t nil)
98 : (esnet ,(purecopy "net Spanish")
99 : nil
100 : iso-spanish iso-cvt-read-only t nil))
101 : "List of information about understood file formats.
102 : Elements are of the form
103 : \(NAME DOC-STR REGEXP FROM-FN TO-FN MODIFY MODE-FN PRESERVE).
104 :
105 : NAME is a symbol, which is stored in `buffer-file-format'.
106 :
107 : DOC-STR should be a single line providing more information about the
108 : format. It is currently unused, but in the future will be shown to
109 : the user if they ask for more information.
110 :
111 : REGEXP is a regular expression to match against the beginning of the file;
112 : it should match only files in that format. REGEXP may be nil, in
113 : which case the format will never be applied automatically to a file.
114 : Use this for formats that you only ever want to apply manually.
115 :
116 : FROM-FN is called to decode files in that format; it takes two args, BEGIN
117 : and END, and can make any modifications it likes, returning the new
118 : end. It must make sure that the beginning of the file no longer
119 : matches REGEXP, or else it will get called again.
120 : Alternatively, FROM-FN can be a string, which specifies a shell command
121 : (including options) to be used as a filter to perform the conversion.
122 :
123 : TO-FN is called to encode a region into that format; it takes three
124 : arguments: BEGIN, END, and BUFFER. BUFFER is the original buffer that
125 : the data being written came from, which the function could use, for
126 : example, to find the values of local variables. TO-FN should either
127 : return a list of annotations like `write-region-annotate-functions',
128 : or modify the region and return the new end.
129 : Alternatively, TO-FN can be a string, which specifies a shell command
130 : (including options) to be used as a filter to perform the conversion.
131 :
132 : MODIFY, if non-nil, means the TO-FN wants to modify the region. If nil,
133 : TO-FN will not make any changes but will instead return a list of
134 : annotations.
135 :
136 : MODE-FN, if specified, is called when visiting a file with that format.
137 : It is called with a single positive argument, on the assumption
138 : that this would turn on some minor mode.
139 :
140 : PRESERVE, if non-nil, means that `format-write-file' should not remove
141 : this format from `buffer-file-format'.")
142 : ;;;###autoload
143 : (put 'format-alist 'risky-local-variable t)
144 :
145 : ;;; Basic Functions (called from Lisp)
146 :
147 : (defun format-encode-run-method (method from to &optional buffer)
148 : "Translate using METHOD the text from FROM to TO.
149 : If METHOD is a string, it is a shell command (including options);
150 : otherwise, it should be a Lisp function.
151 : BUFFER should be the buffer that the output originally came from."
152 0 : (if (stringp method)
153 0 : (let ((error-buff (get-buffer-create "*Format Errors*"))
154 : (coding-system-for-read 'no-conversion)
155 : format-alist)
156 0 : (with-current-buffer error-buff
157 0 : (widen)
158 0 : (erase-buffer))
159 0 : (if (and (zerop (save-window-excursion
160 0 : (shell-command-on-region from to method t t
161 0 : error-buff)))
162 : ;; gzip gives zero exit status with bad args, for instance.
163 0 : (zerop (with-current-buffer error-buff
164 0 : (buffer-size))))
165 0 : (bury-buffer error-buff)
166 0 : (switch-to-buffer-other-window error-buff)
167 0 : (error "Format encoding failed")))
168 0 : (funcall method from to buffer)))
169 :
170 : (defun format-decode-run-method (method from to &optional _buffer)
171 : "Decode using METHOD the text from FROM to TO.
172 : If METHOD is a string, it is a shell command (including options); otherwise,
173 : it should be a Lisp function. BUFFER is currently ignored."
174 0 : (if (stringp method)
175 0 : (let ((error-buff (get-buffer-create "*Format Errors*"))
176 : (coding-system-for-write 'no-conversion)
177 : format-alist)
178 0 : (with-current-buffer error-buff
179 0 : (widen)
180 0 : (erase-buffer))
181 : ;; We should perhaps go via a temporary buffer and copy it
182 : ;; back, in case of errors.
183 0 : (if (and (zerop (save-window-excursion
184 0 : (shell-command-on-region from to method t t
185 0 : error-buff)))
186 : ;; gzip gives zero exit status with bad args, for instance.
187 0 : (zerop (with-current-buffer error-buff
188 0 : (buffer-size))))
189 0 : (bury-buffer error-buff)
190 0 : (switch-to-buffer-other-window error-buff)
191 0 : (error "Format decoding failed"))
192 0 : (point))
193 0 : (funcall method from to)))
194 :
195 : (defun format-annotate-function (format from to orig-buf format-count)
196 : "Return annotations for writing region as FORMAT.
197 : FORMAT is a symbol naming one of the formats defined in `format-alist'.
198 : It must be a single symbol, not a list like `buffer-file-format'.
199 : FROM and TO delimit the region to be operated on in the current buffer.
200 : ORIG-BUF is the original buffer that the data came from.
201 :
202 : FORMAT-COUNT is an integer specifying how many times this function has
203 : been called in the process of decoding ORIG-BUF.
204 :
205 : This function works like a function in `write-region-annotate-functions':
206 : it either returns a list of annotations, or returns with a different buffer
207 : current, which contains the modified text to write. In the latter case,
208 : this function's value is nil.
209 :
210 : For most purposes, consider using `format-encode-region' instead."
211 : ;; This function is called by write-region (actually
212 : ;; build_annotations) for each element of buffer-file-format.
213 0 : (let* ((info (assq format format-alist))
214 0 : (to-fn (nth 4 info))
215 0 : (modify (nth 5 info)))
216 0 : (if to-fn
217 0 : (if modify
218 : ;; To-function wants to modify region. Copy to safe place.
219 0 : (let ((copy-buf (get-buffer-create (format " *Format Temp %d*"
220 0 : format-count)))
221 0 : (sel-disp selective-display)
222 0 : (multibyte enable-multibyte-characters)
223 0 : (coding-system buffer-file-coding-system))
224 0 : (with-current-buffer copy-buf
225 0 : (setq selective-display sel-disp)
226 0 : (set-buffer-multibyte multibyte)
227 0 : (setq buffer-file-coding-system coding-system))
228 0 : (let ((inhibit-read-only t)) ; bug#14887
229 0 : (copy-to-buffer copy-buf from to)
230 0 : (set-buffer copy-buf)
231 0 : (format-insert-annotations write-region-annotations-so-far from)
232 0 : (format-encode-run-method to-fn (point-min) (point-max)
233 0 : orig-buf))
234 0 : (when (buffer-live-p copy-buf)
235 0 : (with-current-buffer copy-buf
236 : ;; Set write-region-post-annotation-function to
237 : ;; delete the buffer once the write is done, but do
238 : ;; it after running to-fn so it doesn't affect
239 : ;; write-region calls in to-fn.
240 0 : (set (make-local-variable
241 0 : 'write-region-post-annotation-function)
242 0 : 'kill-buffer)))
243 0 : nil)
244 : ;; Otherwise just call function, it will return annotations.
245 0 : (funcall to-fn from to orig-buf)))))
246 :
247 : (defun format-decode (format length &optional visit-flag)
248 : ;; This function is called by insert-file-contents whenever a file is read.
249 : "Decode text from any known FORMAT.
250 : FORMAT is a symbol appearing in `format-alist' or a list of such symbols,
251 : or nil, in which case this function tries to guess the format of the data by
252 : matching against the regular expressions in `format-alist'. After a match is
253 : found and the region decoded, the alist is searched again from the beginning
254 : for another match.
255 :
256 : Second arg LENGTH is the number of characters following point to operate on.
257 : If optional third arg VISIT-FLAG is true, set `buffer-file-format'
258 : to the reverted list of formats used, and call any mode functions defined
259 : for those formats.
260 :
261 : Return the new length of the decoded region.
262 :
263 : For most purposes, consider using `format-decode-region' instead."
264 1176 : (let ((mod (buffer-modified-p))
265 1176 : (begin (point))
266 1176 : (end (+ (point) length)))
267 1176 : (unwind-protect
268 1176 : (progn
269 : ;; Don't record undo information for the decoding.
270 :
271 1176 : (if (null format)
272 : ;; Figure out which format it is in, remember list in `format'.
273 1176 : (let ((try format-alist))
274 6356 : (while try
275 5180 : (let* ((f (car try))
276 5180 : (regexp (nth 2 f))
277 5180 : (p (point)))
278 5180 : (if (and regexp (looking-at regexp)
279 5180 : (< (match-end 0) (+ begin length)))
280 0 : (progn
281 0 : (push (car f) format)
282 : ;; Decode it
283 0 : (if (nth 3 f)
284 0 : (setq end (format-decode-run-method (nth 3 f) begin end)))
285 : ;; Call visit function if required
286 0 : (if (and visit-flag (nth 6 f)) (funcall (nth 6 f) 1))
287 : ;; Safeguard against either of the functions changing pt.
288 0 : (goto-char p)
289 : ;; Rewind list to look for another format
290 0 : (setq try format-alist))
291 5180 : (setq try (cdr try))))))
292 : ;; Deal with given format(s)
293 0 : (or (listp format) (setq format (list format)))
294 0 : (let ((do format) f)
295 0 : (while do
296 0 : (or (setq f (assq (car do) format-alist))
297 0 : (error "Unknown format %s" (car do)))
298 : ;; Decode:
299 0 : (if (nth 3 f)
300 0 : (setq end (format-decode-run-method (nth 3 f) begin end)))
301 : ;; Call visit function if required
302 0 : (if (and visit-flag (nth 6 f)) (funcall (nth 6 f) 1))
303 0 : (setq do (cdr do))))
304 : ;; Encode in the opposite order.
305 1176 : (setq format (reverse format)))
306 1176 : (if visit-flag
307 1176 : (setq buffer-file-format format)))
308 :
309 1176 : (set-buffer-modified-p mod))
310 :
311 : ;; Return new length of region
312 1176 : (- end begin)))
313 :
314 : ;;;
315 : ;;; Interactive functions & entry points
316 : ;;;
317 :
318 : (defun format-decode-buffer (&optional format)
319 : "Translate the buffer from some FORMAT.
320 : If the format is not specified, attempt a regexp-based guess.
321 : Set `buffer-file-format' to the format used, and call any
322 : format-specific mode functions."
323 : (interactive
324 0 : (list (format-read "Translate buffer from format (default guess): ")))
325 0 : (save-excursion
326 0 : (goto-char (point-min))
327 0 : (format-decode format (buffer-size) t)))
328 :
329 : (defun format-decode-region (from to &optional format)
330 : "Decode the region from some format.
331 : Arg FORMAT is optional; if omitted the format will be determined by looking
332 : for identifying regular expressions at the beginning of the region."
333 : (interactive
334 0 : (list (region-beginning) (region-end)
335 0 : (format-read "Translate region from format (default guess): ")))
336 0 : (save-excursion
337 0 : (goto-char from)
338 0 : (format-decode format (- to from) nil)))
339 :
340 : (defun format-encode-buffer (&optional format)
341 : "Translate the buffer into FORMAT.
342 : FORMAT defaults to `buffer-file-format'. It is a symbol naming one of the
343 : formats defined in `format-alist', or a list of such symbols."
344 : (interactive
345 0 : (list (format-read (format "Translate buffer to format (default %s): "
346 0 : buffer-file-format))))
347 0 : (format-encode-region (point-min) (point-max) format))
348 :
349 : (defun format-encode-region (beg end &optional format)
350 : "Translate the region into some FORMAT.
351 : FORMAT defaults to `buffer-file-format'. It is a symbol naming
352 : one of the formats defined in `format-alist', or a list of such symbols."
353 : (interactive
354 0 : (list (region-beginning) (region-end)
355 0 : (format-read (format "Translate region to format (default %s): "
356 0 : buffer-file-format))))
357 0 : (if (null format) (setq format buffer-file-format))
358 0 : (if (symbolp format) (setq format (list format)))
359 0 : (save-excursion
360 0 : (goto-char end)
361 0 : (let ((end (point-marker)))
362 0 : (while format
363 0 : (let* ((info (assq (car format) format-alist))
364 0 : (to-fn (nth 4 info))
365 0 : (modify (nth 5 info)))
366 0 : (if to-fn
367 0 : (if modify
368 0 : (setq end (format-encode-run-method to-fn beg end
369 0 : (current-buffer)))
370 0 : (format-insert-annotations
371 0 : (funcall to-fn beg end (current-buffer)))))
372 0 : (setq format (cdr format)))))))
373 :
374 : (defun format-write-file (filename format &optional confirm)
375 : "Write current buffer into FILENAME, using a format based on FORMAT.
376 : Constructs the actual format starting from FORMAT, then appending
377 : any elements from the value of `buffer-file-format' with a non-nil
378 : `preserve' flag (see the documentation of `format-alist'), if they
379 : are not already present in FORMAT. It then updates `buffer-file-format'
380 : with this format, making it the default for future saves.
381 :
382 : If the buffer is already visiting a file, you can specify a
383 : directory name as FILENAME, to write a file of the same old name
384 : in that directory.
385 :
386 : If optional third arg CONFIRM is non-nil, asks for confirmation before
387 : overwriting an existing file. Interactively, requires confirmation
388 : unless you supply a prefix argument."
389 : (interactive
390 : ;; Same interactive spec as write-file, plus format question.
391 0 : (let* ((file (if buffer-file-name
392 0 : (read-file-name "Write file: "
393 0 : nil nil nil nil)
394 0 : (read-file-name "Write file: "
395 0 : (cdr (assq 'default-directory
396 0 : (buffer-local-variables)))
397 0 : nil nil (buffer-name))))
398 0 : (fmt (format-read (format-message "Write file `%s' in format: "
399 0 : (file-name-nondirectory file)))))
400 0 : (list file fmt (not current-prefix-arg))))
401 0 : (let ((old-formats buffer-file-format)
402 : preserve-formats)
403 0 : (dolist (fmt old-formats)
404 0 : (let ((aelt (assq fmt format-alist)))
405 0 : (if (nth 7 aelt)
406 0 : (push fmt preserve-formats))))
407 0 : (setq buffer-file-format format)
408 0 : (dolist (fmt preserve-formats)
409 0 : (unless (memq fmt buffer-file-format)
410 0 : (setq buffer-file-format (append buffer-file-format (list fmt))))))
411 0 : (write-file filename confirm))
412 :
413 : (defun format-find-file (filename format)
414 : "Find the file FILENAME using data format FORMAT.
415 : If FORMAT is nil then do not do any format conversion."
416 : (interactive
417 : ;; Same interactive spec as write-file, plus format question.
418 0 : (let* ((file (read-file-name "Find file: "))
419 0 : (fmt (format-read (format-message "Read file `%s' in format: "
420 0 : (file-name-nondirectory file)))))
421 0 : (list file fmt)))
422 0 : (let ((format-alist nil))
423 0 : (find-file filename))
424 0 : (if format
425 0 : (format-decode-buffer format)))
426 :
427 : (defun format-insert-file (filename format &optional beg end)
428 : "Insert the contents of file FILENAME using data format FORMAT.
429 : If FORMAT is nil then do not do any format conversion.
430 : The optional third and fourth arguments BEG and END specify
431 : the part (in bytes) of the file to read.
432 :
433 : The return value is like the value of `insert-file-contents':
434 : a list (ABSOLUTE-FILE-NAME SIZE)."
435 : (interactive
436 : ;; Same interactive spec as write-file, plus format question.
437 0 : (let* ((file (read-file-name "Find file: "))
438 0 : (fmt (format-read (format-message "Read file `%s' in format: "
439 0 : (file-name-nondirectory file)))))
440 0 : (list file fmt)))
441 0 : (let (value size old-undo)
442 : ;; Record only one undo entry for the insertion. Inhibit point-motion and
443 : ;; modification hooks as with `insert-file-contents'.
444 0 : (let ((inhibit-point-motion-hooks t)
445 : (inhibit-modification-hooks t))
446 : ;; Don't bind `buffer-undo-list' to t here to assert that
447 : ;; `insert-file-contents' may record whether the buffer was unmodified
448 : ;; before.
449 0 : (let ((format-alist nil))
450 0 : (setq value (insert-file-contents filename nil beg end))
451 0 : (setq size (nth 1 value)))
452 0 : (when (consp buffer-undo-list)
453 0 : (let ((head (car buffer-undo-list)))
454 0 : (when (and (consp head)
455 0 : (equal (car head) (point))
456 0 : (equal (cdr head) (+ (point) size)))
457 : ;; Remove first entry from `buffer-undo-list', we shall insert
458 : ;; another one below.
459 0 : (setq old-undo (cdr buffer-undo-list)))))
460 0 : (when format
461 0 : (let ((buffer-undo-list t))
462 0 : (setq size (format-decode format size)
463 0 : value (list (car value) size)))
464 0 : (unless (eq buffer-undo-list t)
465 0 : (setq buffer-undo-list
466 0 : (cons (cons (point) (+ (point) size)) old-undo)))))
467 0 : (unless inhibit-modification-hooks
468 0 : (run-hook-with-args 'after-change-functions (point) (+ (point) size) 0))
469 0 : value))
470 :
471 : (defun format-read (&optional prompt)
472 : "Read and return the name of a format.
473 : Return value is a list, like `buffer-file-format'; it may be nil.
474 : Formats are defined in `format-alist'. Optional arg is the PROMPT to use."
475 0 : (let* ((table (mapcar (lambda (x) (list (symbol-name (car x))))
476 0 : format-alist))
477 0 : (ans (completing-read (or prompt "Format: ") table nil t)))
478 0 : (if (not (equal "" ans)) (list (intern ans)))))
479 :
480 :
481 : ;;;
482 : ;;; Below are some functions that may be useful in writing encoding and
483 : ;;; decoding functions for use in format-alist.
484 : ;;;
485 :
486 : (defun format-replace-strings (alist &optional reverse beg end)
487 : "Do multiple replacements on the buffer.
488 : ALIST is a list of (FROM . TO) pairs, which should be proper arguments to
489 : `search-forward' and `replace-match', respectively.
490 : Optional second arg REVERSE, if non-nil, means the pairs are (TO . FROM),
491 : so that you can use the same list in both directions if it contains only
492 : literal strings.
493 : Optional args BEG and END specify a region of the buffer on which to operate."
494 0 : (save-excursion
495 0 : (save-restriction
496 0 : (or beg (setq beg (point-min)))
497 0 : (if end (narrow-to-region (point-min) end))
498 0 : (while alist
499 0 : (let ((from (if reverse (cdr (car alist)) (car (car alist))))
500 0 : (to (if reverse (car (car alist)) (cdr (car alist)))))
501 0 : (goto-char beg)
502 0 : (while (search-forward from nil t)
503 0 : (goto-char (match-beginning 0))
504 0 : (insert to)
505 0 : (set-text-properties (- (point) (length to)) (point)
506 0 : (text-properties-at (point)))
507 0 : (delete-region (point) (+ (point) (- (match-end 0)
508 0 : (match-beginning 0)))))
509 0 : (setq alist (cdr alist)))))))
510 :
511 : ;;; Some list-manipulation functions that we need.
512 :
513 : (defun format-delq-cons (cons list)
514 : "Remove the given CONS from LIST by side effect and return the new LIST.
515 : Since CONS could be the first element of LIST, write
516 : \(setq foo \(format-delq-cons element foo)) to be sure of changing
517 : the value of `foo'."
518 0 : (if (eq cons list)
519 0 : (cdr list)
520 0 : (let ((p list))
521 0 : (while (not (eq (cdr p) cons))
522 0 : (if (null p) (error "format-delq-cons: not an element"))
523 0 : (setq p (cdr p)))
524 : ;; Now (cdr p) is the cons to delete
525 0 : (setcdr p (cdr cons))
526 0 : list)))
527 :
528 : (defun format-make-relatively-unique (a b)
529 : "Delete common elements of lists A and B, return as pair.
530 : Compare using `equal'."
531 0 : (let* ((acopy (copy-sequence a))
532 0 : (bcopy (copy-sequence b))
533 0 : (tail acopy))
534 0 : (while tail
535 0 : (let ((dup (member (car tail) bcopy))
536 0 : (next (cdr tail)))
537 0 : (if dup (setq acopy (format-delq-cons tail acopy)
538 0 : bcopy (format-delq-cons dup bcopy)))
539 0 : (setq tail next)))
540 0 : (cons acopy bcopy)))
541 :
542 : (defun format-proper-list-p (list)
543 : "Return t if LIST is a proper list.
544 : A proper list is a list ending with a nil cdr, not with an atom "
545 0 : (when (listp list)
546 0 : (while (consp list)
547 0 : (setq list (cdr list)))
548 0 : (null list)))
549 :
550 : (defun format-reorder (items order)
551 : "Arrange ITEMS to follow partial ORDER.
552 : Elements of ITEMS equal to elements of ORDER will be rearranged
553 : to follow the ORDER. Unmatched items will go last."
554 0 : (if order
555 0 : (let ((item (member (car order) items)))
556 0 : (if item
557 0 : (cons (car item)
558 0 : (format-reorder (format-delq-cons item items)
559 0 : (cdr order)))
560 0 : (format-reorder items (cdr order))))
561 0 : items))
562 :
563 : (put 'face 'format-list-valued t) ; These text-properties take values
564 : (put 'unknown 'format-list-valued t) ; that are lists, the elements of which
565 : ; should be considered separately.
566 : ; See format-deannotate-region and
567 : ; format-annotate-region.
568 :
569 : ;; This text property has list values, but they are treated atomically.
570 :
571 : (put 'display 'format-list-atomic-p t)
572 :
573 : ;;;
574 : ;;; Decoding
575 : ;;;
576 :
577 : (defun format-deannotate-region (from to translations next-fn)
578 : "Translate annotations in the region into text properties.
579 : This sets text properties between FROM to TO as directed by the
580 : TRANSLATIONS and NEXT-FN arguments.
581 :
582 : NEXT-FN is a function that searches forward from point for an annotation.
583 : It should return a list of 4 elements: \(BEGIN END NAME POSITIVE). BEGIN and
584 : END are buffer positions bounding the annotation, NAME is the name searched
585 : for in TRANSLATIONS, and POSITIVE should be non-nil if this annotation marks
586 : the beginning of a region with some property, or nil if it ends the region.
587 : NEXT-FN should return nil if there are no annotations after point.
588 :
589 : The basic format of the TRANSLATIONS argument is described in the
590 : documentation for the `format-annotate-region' function. There are some
591 : additional things to keep in mind for decoding, though:
592 :
593 : When an annotation is found, the TRANSLATIONS list is searched for a
594 : text-property name and value that corresponds to that annotation. If the
595 : text-property has several annotations associated with it, it will be used only
596 : if the other annotations are also in effect at that point. The first match
597 : found whose annotations are all present is used.
598 :
599 : The text property thus determined is set to the value over the region between
600 : the opening and closing annotations. However, if the text-property name has a
601 : non-nil `format-list-valued' property, then the value will be consed onto the
602 : surrounding value of the property, rather than replacing that value.
603 :
604 : There are some special symbols that can be used in the \"property\" slot of
605 : the TRANSLATIONS list: PARAMETER and FUNCTION \(spelled in uppercase).
606 : Annotations listed under the pseudo-property PARAMETER are considered to be
607 : arguments of the immediately surrounding annotation; the text between the
608 : opening and closing parameter annotations is deleted from the buffer but saved
609 : as a string.
610 :
611 : The surrounding annotation should be listed under the pseudo-property
612 : FUNCTION. Instead of inserting a text-property for this annotation,
613 : the function listed in the VALUE slot is called to make whatever
614 : changes are appropriate. It can also return a list of the form
615 : \(START LOC PROP VALUE) which specifies a property to put on. The
616 : function's first two arguments are the START and END locations, and
617 : the rest of the arguments are any PARAMETERs found in that region.
618 :
619 : Any annotations that are found by NEXT-FN but not defined by TRANSLATIONS
620 : are saved as values of the `unknown' text-property \(which is list-valued).
621 : The TRANSLATIONS list should usually contain an entry of the form
622 : (unknown (nil format-annotate-value))
623 : to write these unknown annotations back into the file."
624 0 : (save-excursion
625 0 : (save-restriction
626 0 : (narrow-to-region (point-min) to)
627 0 : (goto-char from)
628 0 : (let (next open-ans todo unknown-ans)
629 0 : (while (setq next (funcall next-fn))
630 0 : (let* ((loc (nth 0 next))
631 0 : (end (nth 1 next))
632 0 : (name (nth 2 next))
633 0 : (positive (nth 3 next))
634 : (found nil))
635 :
636 : ;; Delete the annotation
637 0 : (delete-region loc end)
638 0 : (cond
639 : ;; Positive annotations are stacked, remembering location
640 0 : (positive (push `(,name ((,loc . nil))) open-ans))
641 : ;; It is a negative annotation:
642 : ;; Close the top annotation & add its text property.
643 : ;; If the file's nesting is messed up, the close might not match
644 : ;; the top thing on the open-annotations stack.
645 : ;; If no matching annotation is open, just ignore the close.
646 0 : ((not (assoc name open-ans))
647 0 : (message "Extra closing annotation (%s) in file" name))
648 : ;; If one is open, but not on the top of the stack, close
649 : ;; the things in between as well. Set `found' when the real
650 : ;; one is closed.
651 : (t
652 0 : (while (not found)
653 0 : (let* ((top (car open-ans)) ; first on stack: should match.
654 0 : (top-name (car top)) ; text property name
655 0 : (top-extents (nth 1 top)) ; property regions
656 0 : (params (cdr (cdr top))) ; parameters
657 0 : (aalist translations)
658 : (matched nil))
659 0 : (if (equal name top-name)
660 0 : (setq found t)
661 0 : (message "Improper nesting in file."))
662 : ;; Look through property names in TRANSLATIONS
663 0 : (while aalist
664 0 : (let ((prop (car (car aalist)))
665 0 : (alist (cdr (car aalist))))
666 : ;; And look through values for each property
667 0 : (while alist
668 0 : (let ((value (car (car alist)))
669 0 : (ans (cdr (car alist))))
670 0 : (if (member top-name ans)
671 : ;; This annotation is listed, but still have to
672 : ;; check if multiple annotations are satisfied
673 0 : (if (member nil (mapcar (lambda (r)
674 0 : (assoc r open-ans))
675 0 : ans))
676 : nil ; multiple ans not satisfied
677 : ;; If there are multiple annotations going
678 : ;; into one text property, split up the other
679 : ;; annotations so they apply individually to
680 : ;; the other regions.
681 0 : (setcdr (car top-extents) loc)
682 0 : (let ((to-split ans) this-one extents)
683 0 : (while to-split
684 0 : (setq this-one
685 0 : (assoc (car to-split) open-ans)
686 0 : extents (nth 1 this-one))
687 0 : (if (not (eq this-one top))
688 0 : (setcar (cdr this-one)
689 0 : (format-subtract-regions
690 0 : extents top-extents)))
691 0 : (setq to-split (cdr to-split))))
692 : ;; Set loop variables to nil so loop
693 : ;; will exit.
694 0 : (setq alist nil aalist nil matched t
695 : ;; pop annotation off stack.
696 0 : open-ans (cdr open-ans))
697 0 : (let ((extents top-extents)
698 0 : (start (car (car top-extents)))
699 0 : (loc (cdr (car top-extents))))
700 0 : (while extents
701 0 : (cond
702 : ;; Check for pseudo-properties
703 0 : ((eq prop 'PARAMETER)
704 : ;; A parameter of the top open ann:
705 : ;; delete text and use as arg.
706 0 : (if open-ans
707 : ;; (If nothing open, discard).
708 0 : (setq open-ans
709 0 : (cons
710 0 : (append (car open-ans)
711 0 : (list
712 0 : (buffer-substring
713 0 : start loc)))
714 0 : (cdr open-ans))))
715 0 : (delete-region start loc))
716 0 : ((eq prop 'FUNCTION)
717 : ;; Not a property, but a function.
718 0 : (let ((rtn
719 0 : (apply value start loc params)))
720 0 : (if rtn (push rtn todo))))
721 : (t
722 : ;; Normal property/value pair
723 0 : (setq todo
724 0 : (cons (list start loc prop value)
725 0 : todo))))
726 0 : (setq extents (cdr extents)
727 0 : start (car (car extents))
728 0 : loc (cdr (car extents))))))))
729 0 : (setq alist (cdr alist))))
730 0 : (setq aalist (cdr aalist)))
731 0 : (if (not matched)
732 : ;; Didn't find any match for the annotation:
733 : ;; Store as value of text-property `unknown'.
734 0 : (let ((extents top-extents)
735 0 : (start (car (car top-extents)))
736 0 : (loc (or (cdr (car top-extents)) loc)))
737 0 : (while extents
738 0 : (setq open-ans (cdr open-ans)
739 0 : todo (cons (list start loc 'unknown top-name)
740 0 : todo)
741 0 : unknown-ans (cons name unknown-ans)
742 0 : extents (cdr extents)
743 0 : start (car (car extents))
744 0 : loc (cdr (car extents))))))))))))
745 :
746 : ;; Once entire file has been scanned, add the properties.
747 0 : (while todo
748 0 : (let* ((item (car todo))
749 0 : (from (nth 0 item))
750 0 : (to (nth 1 item))
751 0 : (prop (nth 2 item))
752 0 : (val (nth 3 item)))
753 :
754 0 : (if (numberp val) ; add to ambient value if numeric
755 0 : (format-property-increment-region from to prop val 0)
756 0 : (put-text-property
757 0 : from to prop
758 0 : (cond ((get prop 'format-list-valued) ; value gets consed onto
759 : ; list-valued properties
760 0 : (let ((prev (get-text-property from prop)))
761 0 : (cons val (if (listp prev) prev (list prev)))))
762 0 : (t val))))) ; normally, just set to val.
763 0 : (setq todo (cdr todo)))
764 :
765 0 : (if unknown-ans
766 0 : (message "Unknown annotations: %s" unknown-ans))))))
767 :
768 : (defun format-subtract-regions (minu subtra)
769 : "Remove from the regions in MINUEND the regions in SUBTRAHEND.
770 : A region is a dotted pair (FROM . TO). Both parameters are lists of
771 : regions. Each list must contain nonoverlapping, noncontiguous
772 : regions, in descending order. The result is also nonoverlapping,
773 : noncontiguous, and in descending order. The first element of MINUEND
774 : can have a cdr of nil, indicating that the end of that region is not
775 : yet known.
776 :
777 : \(fn MINUEND SUBTRAHEND)"
778 0 : (let* ((minuend (copy-alist minu))
779 0 : (subtrahend (copy-alist subtra))
780 0 : (m (car minuend))
781 0 : (s (car subtrahend))
782 : results)
783 0 : (while (and minuend subtrahend)
784 0 : (cond
785 : ;; The minuend starts after the subtrahend ends; keep it.
786 0 : ((> (car m) (cdr s))
787 0 : (push m results)
788 0 : (setq minuend (cdr minuend)
789 0 : m (car minuend)))
790 : ;; The minuend extends beyond the end of the subtrahend. Chop it off.
791 0 : ((or (null (cdr m)) (> (cdr m) (cdr s)))
792 0 : (push (cons (1+ (cdr s)) (cdr m)) results)
793 0 : (setcdr m (cdr s)))
794 : ;; The subtrahend starts after the minuend ends; throw it away.
795 0 : ((< (cdr m) (car s))
796 0 : (setq subtrahend (cdr subtrahend) s (car subtrahend)))
797 : ;; The subtrahend extends beyond the end of the minuend. Chop it off.
798 : (t ;(<= (cdr m) (cdr s)))
799 0 : (if (>= (car m) (car s))
800 0 : (setq minuend (cdr minuend) m (car minuend))
801 0 : (setcdr m (1- (car s)))
802 0 : (setq subtrahend (cdr subtrahend) s (car subtrahend))))))
803 0 : (nconc (nreverse results) minuend)))
804 :
805 : ;; This should probably go somewhere other than format.el. Then again,
806 : ;; indent.el has alter-text-property. NOTE: We can also use
807 : ;; next-single-property-change instead of text-property-not-all, but then
808 : ;; we have to see if we passed TO.
809 : (defun format-property-increment-region (from to prop delta default)
810 : "In the region from FROM to TO increment property PROP by amount DELTA.
811 : DELTA may be negative. If property PROP is nil anywhere
812 : in the region, it is treated as though it were DEFAULT."
813 0 : (let ((cur from) val newval next)
814 0 : (while cur
815 0 : (setq val (get-text-property cur prop)
816 0 : newval (+ (or val default) delta)
817 0 : next (text-property-not-all cur to prop val))
818 0 : (put-text-property cur (or next to) prop newval)
819 0 : (setq cur next))))
820 :
821 : ;;;
822 : ;;; Encoding
823 : ;;;
824 :
825 : (defun format-insert-annotations (list &optional offset)
826 : "Apply list of annotations to buffer as `write-region' would.
827 : Insert each element of the given LIST of buffer annotations at its
828 : appropriate place. Use second arg OFFSET if the annotations' locations are
829 : not relative to the beginning of the buffer: annotations will be inserted
830 : at their location-OFFSET+1 \(i.e., the offset is treated as the position of
831 : the first character in the buffer)."
832 0 : (if (not offset)
833 0 : (setq offset 0)
834 0 : (setq offset (1- offset)))
835 0 : (let ((l (reverse list)))
836 0 : (while l
837 0 : (goto-char (- (car (car l)) offset))
838 0 : (insert (cdr (car l)))
839 0 : (setq l (cdr l)))))
840 :
841 : (defun format-annotate-value (old new)
842 : "Return OLD and NEW as a (CLOSE . OPEN) annotation pair.
843 : Useful as a default function for TRANSLATIONS alist when the value of the text
844 : property is the name of the annotation that you want to use, as it is for the
845 : `unknown' text property."
846 0 : (cons (if old (list old))
847 0 : (if new (list new))))
848 :
849 : (defun format-annotate-region (from to translations format-fn ignore)
850 : "Generate annotations for text properties in the region.
851 : Search for changes between FROM and TO, and describe them with a list of
852 : annotations as defined by alist TRANSLATIONS and FORMAT-FN. IGNORE lists text
853 : properties not to consider; any text properties that are neither ignored nor
854 : listed in TRANSLATIONS are warned about.
855 : If you actually want to modify the region, give the return value of this
856 : function to `format-insert-annotations'.
857 :
858 : Format of the TRANSLATIONS argument:
859 :
860 : Each element is a list whose car is a PROPERTY, and the following
861 : elements have the form (VALUE ANNOTATIONS...).
862 : Whenever the property takes on the value VALUE, the annotations
863 : \(as formatted by FORMAT-FN) are inserted into the file.
864 : When the property stops having that value, the matching negated annotation
865 : will be inserted \(it may actually be closed earlier and reopened, if
866 : necessary, to keep proper nesting).
867 :
868 : If VALUE is a list, then each element of the list is dealt with
869 : separately.
870 :
871 : If a VALUE is numeric, then it is assumed that there is a single annotation
872 : and each occurrence of it increments the value of the property by that number.
873 : Thus, given the entry \(left-margin \(4 \"indent\")), if the left margin
874 : changes from 4 to 12, two <indent> annotations will be generated.
875 :
876 : If the VALUE is nil, then instead of annotations, a function should be
877 : specified. This function is used as a default: it is called for all
878 : transitions not explicitly listed in the table. The function is called with
879 : two arguments, the OLD and NEW values of the property. It should return
880 : a cons cell (CLOSE . OPEN) as `format-annotate-single-property-change' does.
881 :
882 : The same TRANSLATIONS structure can be used in reverse for reading files."
883 0 : (let ((all-ans nil) ; All annotations - becomes return value
884 : (open-ans nil) ; Annotations not yet closed
885 : (loc nil) ; Current location
886 : (not-found nil)) ; Properties that couldn't be saved
887 0 : (while (or (null loc)
888 0 : (and (setq loc (next-property-change loc nil to))
889 0 : (< loc to)))
890 0 : (or loc (setq loc from))
891 0 : (let* ((ans (format-annotate-location loc (= loc from) ignore translations))
892 0 : (neg-ans (format-reorder (aref ans 0) open-ans))
893 0 : (pos-ans (aref ans 1))
894 0 : (ignored (aref ans 2)))
895 0 : (setq not-found (append ignored not-found)
896 0 : ignore (append ignored ignore))
897 : ;; First do the negative (closing) annotations
898 0 : (while neg-ans
899 : ;; Check if it's missing. This can happen (eg, a numeric property
900 : ;; going negative can generate closing annotations before there are
901 : ;; any open). Warn user & ignore.
902 0 : (if (not (member (car neg-ans) open-ans))
903 0 : (message "Can't close %s: not open." (car neg-ans))
904 0 : (while (not (equal (car neg-ans) (car open-ans)))
905 : ;; To close anno. N, need to first close ans 1 to N-1,
906 : ;; remembering to re-open them later.
907 0 : (push (car open-ans) pos-ans)
908 0 : (setq all-ans
909 0 : (cons (cons loc (funcall format-fn (car open-ans) nil))
910 0 : all-ans))
911 0 : (setq open-ans (cdr open-ans)))
912 : ;; Now remove the one we're really interested in from open list.
913 0 : (setq open-ans (cdr open-ans))
914 : ;; And put the closing annotation here.
915 0 : (push (cons loc (funcall format-fn (car neg-ans) nil))
916 0 : all-ans))
917 0 : (setq neg-ans (cdr neg-ans)))
918 : ;; Now deal with positive (opening) annotations
919 0 : (while pos-ans
920 0 : (push (car pos-ans) open-ans)
921 0 : (push (cons loc (funcall format-fn (car pos-ans) t))
922 0 : all-ans)
923 0 : (setq pos-ans (cdr pos-ans)))))
924 :
925 : ;; Close any annotations still open
926 0 : (while open-ans
927 0 : (setq all-ans
928 0 : (cons (cons to (funcall format-fn (car open-ans) nil))
929 0 : all-ans))
930 0 : (setq open-ans (cdr open-ans)))
931 0 : (if not-found
932 0 : (message "These text properties could not be saved:\n %s"
933 0 : not-found))
934 0 : (nreverse all-ans)))
935 :
936 : ;;; Internal functions for format-annotate-region.
937 :
938 : (defun format-annotate-location (loc all ignore translations)
939 : "Return annotation(s) needed at location LOC.
940 : This includes any properties that change between LOC - 1 and LOC.
941 : If ALL is true, don't look at previous location, but generate annotations for
942 : all non-nil properties.
943 : Third argument IGNORE is a list of text-properties not to consider.
944 : Use the TRANSLATIONS alist (see `format-annotate-region' for doc).
945 :
946 : Return value is a vector of 3 elements:
947 : 1. List of annotations to close
948 : 2. List of annotations to open.
949 : 3. List of properties that were ignored or couldn't be annotated.
950 :
951 : The annotations in lists 1 and 2 need not be strings.
952 : They can be whatever the FORMAT-FN in `format-annotate-region'
953 : can handle. If that is `enriched-make-annotation', they can be
954 : either strings, or lists of the form (PARAMETER VALUE)."
955 0 : (let* ((prev-loc (1- loc))
956 0 : (before-plist (if all nil (text-properties-at prev-loc)))
957 0 : (after-plist (text-properties-at loc))
958 : p negatives positives prop props not-found)
959 : ;; make list of all property names involved
960 0 : (setq p before-plist)
961 0 : (while p
962 0 : (if (not (memq (car p) props))
963 0 : (push (car p) props))
964 0 : (setq p (cdr (cdr p))))
965 0 : (setq p after-plist)
966 0 : (while p
967 0 : (if (not (memq (car p) props))
968 0 : (push (car p) props))
969 0 : (setq p (cdr (cdr p))))
970 :
971 0 : (while props
972 0 : (setq prop (pop props))
973 0 : (if (memq prop ignore)
974 : nil ; If it's been ignored before, ignore it now.
975 0 : (let ((before (if all nil (car (cdr (memq prop before-plist)))))
976 0 : (after (car (cdr (memq prop after-plist)))))
977 0 : (if (equal before after)
978 : nil ; no change; ignore
979 0 : (let ((result (format-annotate-single-property-change
980 0 : prop before after translations)))
981 0 : (if (not result)
982 0 : (push prop not-found)
983 0 : (setq negatives (nconc negatives (car result))
984 0 : positives (nconc positives (cdr result)))))))))
985 0 : (vector negatives positives not-found)))
986 :
987 : (defun format-annotate-single-property-change (prop old new translations)
988 : "Return annotations for property PROP changing from OLD to NEW.
989 : These are searched for in the translations alist TRANSLATIONS
990 : (see `format-annotate-region' for the format).
991 : If NEW does not appear in the list, but there is a default function,
992 : then call that function.
993 : Return a cons of the form (CLOSE . OPEN)
994 : where CLOSE is a list of annotations to close
995 : and OPEN is a list of annotations to open.
996 :
997 : The annotations in CLOSE and OPEN need not be strings.
998 : They can be whatever the FORMAT-FN in `format-annotate-region'
999 : can handle. If that is `enriched-make-annotation', they can be
1000 : either strings, or lists of the form (PARAMETER VALUE)."
1001 :
1002 0 : (let ((prop-alist (cdr (assoc prop translations))))
1003 0 : (if (not prop-alist)
1004 : nil
1005 : ;; If either old or new is a list, have to treat both that way.
1006 0 : (if (and (or (listp old) (listp new))
1007 0 : (not (get prop 'format-list-atomic-p)))
1008 0 : (if (or (not (format-proper-list-p old))
1009 0 : (not (format-proper-list-p new)))
1010 0 : (format-annotate-atomic-property-change prop-alist old new)
1011 0 : (let* ((old (if (listp old) old (list old)))
1012 0 : (new (if (listp new) new (list new)))
1013 : close open)
1014 0 : (while old
1015 0 : (setq close
1016 0 : (append (car (format-annotate-atomic-property-change
1017 0 : prop-alist (car old) nil))
1018 0 : close)
1019 0 : old (cdr old)))
1020 0 : (while new
1021 0 : (setq open
1022 0 : (append (cdr (format-annotate-atomic-property-change
1023 0 : prop-alist nil (car new)))
1024 0 : open)
1025 0 : new (cdr new)))
1026 0 : (format-make-relatively-unique close open)))
1027 0 : (format-annotate-atomic-property-change prop-alist old new)))))
1028 :
1029 : (defun format-annotate-atomic-property-change (prop-alist old new)
1030 : "Internal function to annotate a single property change.
1031 : PROP-ALIST is the relevant element of a TRANSLATIONS list.
1032 : OLD and NEW are the values."
1033 0 : (let (num-ann)
1034 : ;; If old and new values are numbers,
1035 : ;; look for a number in PROP-ALIST.
1036 0 : (if (and (or (null old) (numberp old))
1037 0 : (or (null new) (numberp new)))
1038 0 : (progn
1039 0 : (setq num-ann prop-alist)
1040 0 : (while (and num-ann (not (numberp (car (car num-ann)))))
1041 0 : (setq num-ann (cdr num-ann)))))
1042 0 : (if num-ann
1043 : ;; Numerical annotation - use difference
1044 0 : (progn
1045 : ;; If property is numeric, nil means 0
1046 0 : (cond ((and (numberp old) (null new))
1047 0 : (setq new 0))
1048 0 : ((and (numberp new) (null old))
1049 0 : (setq old 0)))
1050 :
1051 0 : (let* ((entry (car num-ann))
1052 0 : (increment (car entry))
1053 0 : (n (ceiling (/ (float (- new old)) (float increment))))
1054 0 : (anno (car (cdr entry))))
1055 0 : (if (> n 0)
1056 0 : (cons nil (make-list n anno))
1057 0 : (cons (make-list (- n) anno) nil))))
1058 :
1059 : ;; Standard annotation
1060 0 : (let ((close (and old (cdr (assoc old prop-alist))))
1061 0 : (open (and new (cdr (assoc new prop-alist)))))
1062 0 : (if (or close open)
1063 0 : (format-make-relatively-unique close open)
1064 : ;; Call "Default" function, if any
1065 0 : (let ((default (assq nil prop-alist)))
1066 0 : (if default
1067 0 : (funcall (car (cdr default)) old new))))))))
1068 :
1069 : (provide 'format)
1070 :
1071 : ;;; format.el ends here
|