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comparison lisp/format.el @ 428:3ecd8885ac67 r21-2-22
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date | Mon, 13 Aug 2007 11:28:15 +0200 |
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1 ;;; format.el --- read and save files in multiple formats | |
2 | |
3 ;; Copyright (c) 1994, 1995, 1997 Free Software Foundation | |
4 | |
5 ;; Author: Boris Goldowsky <boris@gnu.ai.mit.edu> | |
6 ;; Keywords: extensions, dumped | |
7 | |
8 ;; This file is part of XEmacs. | |
9 | |
10 ;; XEmacs is free software; you can redistribute it and/or modify it | |
11 ;; under the terms of the GNU General Public License as published by | |
12 ;; the Free Software Foundation; either version 2, or (at your option) | |
13 ;; any later version. | |
14 | |
15 ;; XEmacs is distributed in the hope that it will be useful, but | |
16 ;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 ;; General Public License for more details. | |
19 | |
20 ;; You should have received a copy of the GNU General Public License | |
21 ;; along with XEmacs; see the file COPYING. If not, write to the Free | |
22 ;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
23 ;; 02111-1307, USA. | |
24 | |
25 ;;; Synched up with: Emacs 20.2. | |
26 | |
27 ;;; Commentary: | |
28 | |
29 ;; This file is dumped with XEmacs. | |
30 | |
31 ;; This file defines a unified mechanism for saving & loading files stored | |
32 ;; in different formats. `format-alist' contains information that directs | |
33 ;; Emacs to call an encoding or decoding function when reading or writing | |
34 ;; files that match certain conditions. | |
35 ;; | |
36 ;; When a file is visited, its format is determined by matching the | |
37 ;; beginning of the file against regular expressions stored in | |
38 ;; `format-alist'. If this fails, you can manually translate the buffer | |
39 ;; using `format-decode-buffer'. In either case, the formats used are | |
40 ;; listed in the variable `buffer-file-format', and become the default | |
41 ;; format for saving the buffer. To save a buffer in a different format, | |
42 ;; change this variable, or use `format-write-file'. | |
43 ;; | |
44 ;; Auto-save files are normally created in the same format as the visited | |
45 ;; file, but the variable `auto-save-file-format' can be set to a | |
46 ;; particularly fast or otherwise preferred format to be used for | |
47 ;; auto-saving (or nil to do no encoding on auto-save files, but then you | |
48 ;; risk losing any text-properties in the buffer). | |
49 ;; | |
50 ;; You can manually translate a buffer into or out of a particular format | |
51 ;; with the functions `format-encode-buffer' and `format-decode-buffer'. | |
52 ;; To translate just the region use the functions `format-encode-region' | |
53 ;; and `format-decode-region'. | |
54 ;; | |
55 ;; You can define a new format by writing the encoding and decoding | |
56 ;; functions, and adding an entry to `format-alist'. See enriched.el for | |
57 ;; an example of how to implement a file format. There are various | |
58 ;; functions defined in this file that may be useful for writing the | |
59 ;; encoding and decoding functions: | |
60 ;; * `format-annotate-region' and `format-deannotate-region' allow a | |
61 ;; single alist of information to be used for encoding and decoding. | |
62 ;; The alist defines a correspondence between strings in the file | |
63 ;; ("annotations") and text-properties in the buffer. | |
64 ;; * `format-replace-strings' is similarly useful for doing simple | |
65 ;; string->string translations in a reversible manner. | |
66 | |
67 ;;; Code: | |
68 | |
69 (put 'buffer-file-format 'permanent-local t) | |
70 | |
71 (defvar format-alist | |
72 '( | |
73 ; (image/jpeg "JPEG image" "\377\330\377\340\000\020JFIF" | |
74 ; image-decode-jpeg nil t image-mode) | |
75 ; (image/gif "GIF image" "GIF8[79]" | |
76 ; image-decode-gif nil t image-mode) | |
77 ; (image/png "Portable Network Graphics" "\211PNG" | |
78 ; image-decode-png nil t image-mode) | |
79 ; (image/x-xpm "XPM image" "/\\* XPM \\*/" | |
80 ; image-decode-xpm nil t image-mode) | |
81 | |
82 ; ;; TIFF files have lousy magic | |
83 ; (image/tiff "TIFF image" "II\\*\000" | |
84 ; image-decode-tiff nil t image-mode) ;; TIFF 6.0 big-endian | |
85 ; (image/tiff "TIFF image" "MM\000\\*" | |
86 ; image-decode-tiff nil t image-mode) ;; TIFF 6.0 little-endian | |
87 | |
88 (text/enriched "Extended MIME text/enriched format." | |
89 "Content-[Tt]ype:[ \t]*text/enriched" | |
90 enriched-decode enriched-encode t enriched-mode) | |
91 (text/richtext "Extended MIME obsolete text/richtext format." | |
92 "Content-[Tt]ype:[ \t]*text/richtext" | |
93 richtext-decode richtext-encode t enriched-mode) | |
94 (plain "ISO 8859-1 standard format, no text properties." | |
95 ;; Plain only exists so that there is an obvious neutral choice in | |
96 ;; the completion list. | |
97 nil nil nil nil nil) | |
98 ;; (ibm "IBM Code Page 850 (DOS)" | |
99 ;; "1\\(^\\)" | |
100 ;; "recode ibm-pc:latin1" "recode latin1:ibm-pc" t nil) | |
101 ;; (mac "Apple Macintosh" | |
102 ;; "1\\(^\\)" | |
103 ;; "recode mac:latin1" "recode latin1:mac" t nil) | |
104 ;; (hp "HP Roman8" | |
105 ;; "1\\(^\\)" | |
106 ;; "recode roman8:latin1" "recode latin1:roman8" t nil) | |
107 ;; (TeX "TeX (encoding)" | |
108 ;; "1\\(^\\)" | |
109 ;; iso-tex2iso iso-iso2tex t nil) | |
110 ;; (gtex "German TeX (encoding)" | |
111 ;; "1\\(^\\)" | |
112 ;; iso-gtex2iso iso-iso2gtex t nil) | |
113 ;; (html "HTML (encoding)" | |
114 ;; "1\\(^\\)" | |
115 ;; "recode html:latin1" "recode latin1:html" t nil) | |
116 ;; (rot13 "rot13" | |
117 ;; "1\\(^\\)" | |
118 ;; "tr a-mn-z n-za-m" "tr a-mn-z n-za-m" t nil) | |
119 ;; (duden "Duden Ersatzdarstellung" | |
120 ;; "1\\(^\\)" | |
121 ;; "diac" iso-iso2duden t nil) | |
122 ;; (de646 "German ASCII (ISO 646)" | |
123 ;; "1\\(^\\)" | |
124 ;; "recode iso646-ge:latin1" "recode latin1:iso646-ge" t nil) | |
125 ;; (denet "net German" | |
126 ;; "1\\(^\\)" | |
127 ;; iso-german iso-cvt-read-only t nil) | |
128 ;; (esnet "net Spanish" | |
129 ;; "1\\(^\\)" | |
130 ;; iso-spanish iso-cvt-read-only t nil) | |
131 ) | |
132 "List of information about understood file formats. | |
133 Elements are of the form \(NAME DOC-STR REGEXP FROM-FN TO-FN MODIFY MODE-FN). | |
134 | |
135 NAME is a symbol, which is stored in `buffer-file-format'. | |
136 | |
137 DOC-STR should be a single line providing more information about the | |
138 format. It is currently unused, but in the future will be shown to | |
139 the user if they ask for more information. | |
140 | |
141 REGEXP is a regular expression to match against the beginning of the file; | |
142 it should match only files in that format. | |
143 | |
144 FROM-FN is called to decode files in that format; it gets two args, BEGIN | |
145 and END, and can make any modifications it likes, returning the new | |
146 end. It must make sure that the beginning of the file no longer | |
147 matches REGEXP, or else it will get called again. | |
148 Alternatively, FROM-FN can be a string, which specifies a shell command | |
149 (including options) to be used as a filter to perform the conversion. | |
150 | |
151 TO-FN is called to encode a region into that format; it is passed three | |
152 arguments: BEGIN, END, and BUFFER. BUFFER is the original buffer that | |
153 the data being written came from, which the function could use, for | |
154 example, to find the values of local variables. TO-FN should either | |
155 return a list of annotations like `write-region-annotate-functions', | |
156 or modify the region and return the new end. | |
157 Alternatively, TO-FN can be a string, which specifies a shell command | |
158 (including options) to be used as a filter to perform the conversion. | |
159 | |
160 MODIFY, if non-nil, means the TO-FN wants to modify the region. If nil, | |
161 TO-FN will not make any changes but will instead return a list of | |
162 annotations. | |
163 | |
164 MODE-FN, if specified, is called when visiting a file with that format.") | |
165 | |
166 ;;; Basic Functions (called from Lisp) | |
167 | |
168 (defun format-encode-run-method (method from to &optional buffer) | |
169 "Translate using function or shell script METHOD the text from FROM to TO. | |
170 If METHOD is a string, it is a shell command; | |
171 otherwise, it should be a Lisp function. | |
172 BUFFER should be the buffer that the output originally came from." | |
173 (if (stringp method) | |
174 (save-current-buffer | |
175 (set-buffer buffer) | |
176 (with-output-to-temp-buffer "*Format Errors*" | |
177 (shell-command-on-region from to method t nil)) | |
178 (point)) | |
179 (funcall method from to buffer))) | |
180 | |
181 (defun format-decode-run-method (method from to &optional buffer) | |
182 "Decode using function or shell script METHOD the text from FROM to TO. | |
183 If METHOD is a string, it is a shell command; | |
184 otherwise, it should be a Lisp function." | |
185 (if (stringp method) | |
186 (progn | |
187 (with-output-to-temp-buffer "*Format Errors*" | |
188 (shell-command-on-region from to method t nil)) | |
189 (point)) | |
190 (funcall method from to))) | |
191 | |
192 (defun format-annotate-function (format from to orig-buf) | |
193 "Return annotations for writing region as FORMAT. | |
194 FORMAT is a symbol naming one of the formats defined in `format-alist', | |
195 it must be a single symbol, not a list like `buffer-file-format'. | |
196 FROM and TO delimit the region to be operated on in the current buffer. | |
197 ORIG-BUF is the original buffer that the data came from. | |
198 This function works like a function on `write-region-annotate-functions': | |
199 it either returns a list of annotations, or returns with a different buffer | |
200 current, which contains the modified text to write. | |
201 | |
202 For most purposes, consider using `format-encode-region' instead." | |
203 ;; This function is called by write-region (actually build-annotations) | |
204 ;; for each element of buffer-file-format. | |
205 (let* ((info (assq format format-alist)) | |
206 (to-fn (nth 4 info)) | |
207 (modify (nth 5 info))) | |
208 (if to-fn | |
209 (if modify | |
210 ;; To-function wants to modify region. Copy to safe place. | |
211 (let ((copy-buf (get-buffer-create " *Format Temp*"))) | |
212 (copy-to-buffer copy-buf from to) | |
213 (set-buffer copy-buf) | |
214 (format-insert-annotations write-region-annotations-so-far from) | |
215 (format-encode-run-method to-fn (point-min) (point-max) orig-buf) | |
216 nil) | |
217 ;; Otherwise just call function, it will return annotations. | |
218 (funcall to-fn from to orig-buf))))) | |
219 | |
220 (defun format-decode (format length &optional visit-flag) | |
221 "Decode text from any known FORMAT. | |
222 FORMAT is a symbol appearing in `format-alist' or a list of such symbols, | |
223 or nil, in which case this function tries to guess the format of the data by | |
224 matching against the regular expressions in `format-alist'. After a match is | |
225 found and the region decoded, the alist is searched again from the beginning | |
226 for another match. | |
227 | |
228 Second arg LENGTH is the number of characters following point to operate on. | |
229 If optional third arg VISIT-FLAG is true, set `buffer-file-format' | |
230 to the list of formats used, and call any mode functions defined for those | |
231 formats. | |
232 | |
233 Returns the new length of the decoded region. | |
234 | |
235 For most purposes, consider using `format-decode-region' instead. | |
236 | |
237 This function is called by insert-file-contents whenever a file is read." | |
238 (let ((mod (buffer-modified-p)) | |
239 (begin (point)) | |
240 (end (+ (point) length))) | |
241 (if (null format) | |
242 ;; Figure out which format it is in, remember list in `format'. | |
243 (let ((try format-alist)) | |
244 (while try | |
245 (let* ((f (car try)) | |
246 (regexp (nth 2 f)) | |
247 (p (point))) | |
248 (if (and regexp (looking-at regexp) | |
249 (< (match-end 0) (+ begin length))) | |
250 (progn | |
251 (setq format (cons (car f) format)) | |
252 ;; Decode it | |
253 (if (nth 3 f) | |
254 (setq end (format-decode-run-method (nth 3 f) begin end))) | |
255 ;; Call visit function if required | |
256 (if (and visit-flag (nth 6 f)) (funcall (nth 6 f) 1)) | |
257 ;; Safeguard against either of the functions changing pt. | |
258 (goto-char p) | |
259 ;; Rewind list to look for another format | |
260 (setq try format-alist)) | |
261 (setq try (cdr try)))))) | |
262 ;; Deal with given format(s) | |
263 (or (listp format) (setq format (list format))) | |
264 (let ((do format) f) | |
265 (while do | |
266 (or (setq f (assq (car do) format-alist)) | |
267 (error "Unknown format" (car do))) | |
268 ;; Decode: | |
269 (if (nth 3 f) | |
270 (setq end (format-decode-run-method (nth 3 f) begin end))) | |
271 ;; Call visit function if required | |
272 (if (and visit-flag (nth 6 f)) (funcall (nth 6 f) 1)) | |
273 (setq do (cdr do))))) | |
274 (if visit-flag | |
275 (setq buffer-file-format format)) | |
276 (set-buffer-modified-p mod) | |
277 ;; Return new length of region | |
278 (- end begin))) | |
279 | |
280 ;;; | |
281 ;;; Interactive functions & entry points | |
282 ;;; | |
283 | |
284 (defun format-decode-buffer (&optional format) | |
285 "Translate the buffer from some FORMAT. | |
286 If the format is not specified, this function attempts to guess. | |
287 `buffer-file-format' is set to the format used, and any mode-functions | |
288 for the format are called." | |
289 (interactive | |
290 (list (format-read "Translate buffer from format (default: guess): "))) | |
291 (save-excursion | |
292 (goto-char (point-min)) | |
293 (format-decode format (buffer-size) t))) | |
294 | |
295 (defun format-decode-region (from to &optional format) | |
296 "Decode the region from some format. | |
297 Arg FORMAT is optional; if omitted the format will be determined by looking | |
298 for identifying regular expressions at the beginning of the region." | |
299 (interactive | |
300 (list (region-beginning) (region-end) | |
301 (format-read "Translate region from format (default: guess): "))) | |
302 (save-excursion | |
303 (goto-char from) | |
304 (format-decode format (- to from) nil))) | |
305 | |
306 (defun format-encode-buffer (&optional format) | |
307 "Translate the buffer into FORMAT. | |
308 FORMAT defaults to `buffer-file-format'. It is a symbol naming one of the | |
309 formats defined in `format-alist', or a list of such symbols." | |
310 (interactive | |
311 (list (format-read (format "Translate buffer to format (default %s): " | |
312 buffer-file-format)))) | |
313 (format-encode-region (point-min) (point-max) format)) | |
314 | |
315 (defun format-encode-region (beg end &optional format) | |
316 "Translate the region into some FORMAT. | |
317 FORMAT defaults to `buffer-file-format', it is a symbol naming | |
318 one of the formats defined in `format-alist', or a list of such symbols." | |
319 (interactive | |
320 (list (region-beginning) (region-end) | |
321 (format-read (format "Translate region to format (default %s): " | |
322 buffer-file-format)))) | |
323 (if (null format) (setq format buffer-file-format)) | |
324 (if (symbolp format) (setq format (list format))) | |
325 (save-excursion | |
326 (goto-char end) | |
327 (let ( ; (cur-buf (current-buffer)) | |
328 (end (point-marker))) | |
329 (while format | |
330 (let* ((info (assq (car format) format-alist)) | |
331 (to-fn (nth 4 info)) | |
332 (modify (nth 5 info)) | |
333 ;; result | |
334 ) | |
335 (if to-fn | |
336 (if modify | |
337 (setq end (format-encode-run-method to-fn beg end | |
338 (current-buffer))) | |
339 (format-insert-annotations | |
340 (funcall to-fn beg end (current-buffer))))) | |
341 (setq format (cdr format))))))) | |
342 | |
343 (defun format-write-file (filename format) | |
344 "Write current buffer into a FILE using some FORMAT. | |
345 Makes buffer visit that file and sets the format as the default for future | |
346 saves. If the buffer is already visiting a file, you can specify a directory | |
347 name as FILE, to write a file of the same old name in that directory." | |
348 (interactive | |
349 ;; Same interactive spec as write-file, plus format question. | |
350 (let* ((file (if buffer-file-name | |
351 (read-file-name "Write file: " | |
352 nil nil nil nil) | |
353 (read-file-name "Write file: " | |
354 (cdr (assq 'default-directory | |
355 (buffer-local-variables))) | |
356 nil nil (buffer-name)))) | |
357 (fmt (format-read (format "Write file `%s' in format: " | |
358 (file-name-nondirectory file))))) | |
359 (list file fmt))) | |
360 (setq buffer-file-format format) | |
361 (write-file filename)) | |
362 | |
363 (defun format-find-file (filename format) | |
364 "Find the file FILE using data format FORMAT. | |
365 If FORMAT is nil then do not do any format conversion." | |
366 (interactive | |
367 ;; Same interactive spec as write-file, plus format question. | |
368 (let* ((file (read-file-name "Find file: ")) | |
369 (fmt (format-read (format "Read file `%s' in format: " | |
370 (file-name-nondirectory file))))) | |
371 (list file fmt))) | |
372 (let ((format-alist nil)) | |
373 (find-file filename)) | |
374 (if format | |
375 (format-decode-buffer format))) | |
376 | |
377 (defun format-insert-file (filename format &optional beg end) | |
378 "Insert the contents of file FILE using data format FORMAT. | |
379 If FORMAT is nil then do not do any format conversion. | |
380 The optional third and fourth arguments BEG and END specify | |
381 the part of the file to read. | |
382 | |
383 The return value is like the value of `insert-file-contents': | |
384 a list (ABSOLUTE-FILE-NAME . SIZE)." | |
385 (interactive | |
386 ;; Same interactive spec as write-file, plus format question. | |
387 (let* ((file (read-file-name "Find file: ")) | |
388 (fmt (format-read (format "Read file `%s' in format: " | |
389 (file-name-nondirectory file))))) | |
390 (list file fmt))) | |
391 (let (value size) | |
392 (let ((format-alist nil)) | |
393 (setq value (insert-file-contents filename nil beg end)) | |
394 (setq size (nth 1 value))) | |
395 (if format | |
396 (setq size (format-decode format size) | |
397 value (cons (car value) size))) | |
398 value)) | |
399 | |
400 (defun format-read (&optional prompt) | |
401 "Read and return the name of a format. | |
402 Return value is a list, like `buffer-file-format'; it may be nil. | |
403 Formats are defined in `format-alist'. Optional arg is the PROMPT to use." | |
404 (let* ((table (mapcar (lambda (x) (list (symbol-name (car x)))) | |
405 format-alist)) | |
406 (ans (completing-read (or prompt "Format: ") table nil t))) | |
407 (if (not (equal "" ans)) (list (intern ans))))) | |
408 | |
409 | |
410 ;;; | |
411 ;;; Below are some functions that may be useful in writing encoding and | |
412 ;;; decoding functions for use in format-alist. | |
413 ;;; | |
414 | |
415 (defun format-replace-strings (alist &optional reverse beg end) | |
416 "Do multiple replacements on the buffer. | |
417 ALIST is a list of (from . to) pairs, which should be proper arguments to | |
418 `search-forward' and `replace-match' respectively. | |
419 Optional 2nd arg REVERSE, if non-nil, means the pairs are (to . from), so that | |
420 you can use the same list in both directions if it contains only literal | |
421 strings. | |
422 Optional args BEGIN and END specify a region of the buffer to operate on." | |
423 (save-excursion | |
424 (save-restriction | |
425 (or beg (setq beg (point-min))) | |
426 (if end (narrow-to-region (point-min) end)) | |
427 (while alist | |
428 (let ((from (if reverse (cdr (car alist)) (car (car alist)))) | |
429 (to (if reverse (car (cdr alist)) (cdr (car alist))))) | |
430 (goto-char beg) | |
431 (while (search-forward from nil t) | |
432 (goto-char (match-beginning 0)) | |
433 (insert to) | |
434 (set-text-properties (- (point) (length to)) (point) | |
435 (text-properties-at (point))) | |
436 (delete-region (point) (+ (point) (- (match-end 0) | |
437 (match-beginning 0))))) | |
438 (setq alist (cdr alist))))))) | |
439 | |
440 ;;; Some list-manipulation functions that we need. | |
441 | |
442 (defun format-delq-cons (cons list) | |
443 "Remove the given CONS from LIST by side effect, | |
444 and return the new LIST. Since CONS could be the first element | |
445 of LIST, write `\(setq foo \(format-delq-cons element foo))' to be sure of | |
446 changing the value of `foo'." | |
447 (if (eq cons list) | |
448 (cdr list) | |
449 (let ((p list)) | |
450 (while (not (eq (cdr p) cons)) | |
451 (if (null p) (error "format-delq-cons: not an element.")) | |
452 (setq p (cdr p))) | |
453 ;; Now (cdr p) is the cons to delete | |
454 (setcdr p (cdr cons)) | |
455 list))) | |
456 | |
457 (defun format-make-relatively-unique (a b) | |
458 "Delete common elements of lists A and B, return as pair. | |
459 Compares using `equal'." | |
460 (let* ((acopy (copy-sequence a)) | |
461 (bcopy (copy-sequence b)) | |
462 (tail acopy)) | |
463 (while tail | |
464 (let ((dup (member (car tail) bcopy)) | |
465 (next (cdr tail))) | |
466 (if dup (setq acopy (format-delq-cons tail acopy) | |
467 bcopy (format-delq-cons dup bcopy))) | |
468 (setq tail next))) | |
469 (cons acopy bcopy))) | |
470 | |
471 (defun format-common-tail (a b) | |
472 "Given two lists that have a common tail, return it. | |
473 Compares with `equal', and returns the part of A that is equal to the | |
474 equivalent part of B. If even the last items of the two are not equal, | |
475 returns nil." | |
476 (let ((la (length a)) | |
477 (lb (length b))) | |
478 ;; Make sure they are the same length | |
479 (if (> la lb) | |
480 (setq a (nthcdr (- la lb) a)) | |
481 (setq b (nthcdr (- lb la) b)))) | |
482 (while (not (equal a b)) | |
483 (setq a (cdr a) | |
484 b (cdr b))) | |
485 a) | |
486 | |
487 (defun format-reorder (items order) | |
488 "Arrange ITEMS to following partial ORDER. | |
489 Elements of ITEMS equal to elements of ORDER will be rearranged to follow the | |
490 ORDER. Unmatched items will go last." | |
491 (if order | |
492 (let ((item (member (car order) items))) | |
493 (if item | |
494 (cons (car item) | |
495 (format-reorder (format-delq-cons item items) | |
496 (cdr order))) | |
497 (format-reorder items (cdr order)))) | |
498 items)) | |
499 | |
500 (put 'face 'format-list-valued t) ; These text-properties take values | |
501 (put 'unknown 'format-list-valued t) ; that are lists, the elements of which | |
502 ; should be considered separately. | |
503 ; See format-deannotate-region and | |
504 ; format-annotate-region. | |
505 | |
506 ;;; | |
507 ;;; Decoding | |
508 ;;; | |
509 | |
510 (defun format-deannotate-region (from to translations next-fn) | |
511 "Translate annotations in the region into text properties. | |
512 This sets text properties between FROM to TO as directed by the | |
513 TRANSLATIONS and NEXT-FN arguments. | |
514 | |
515 NEXT-FN is a function that searches forward from point for an annotation. | |
516 It should return a list of 4 elements: \(BEGIN END NAME POSITIVE). BEGIN and | |
517 END are buffer positions bounding the annotation, NAME is the name searched | |
518 for in TRANSLATIONS, and POSITIVE should be non-nil if this annotation marks | |
519 the beginning of a region with some property, or nil if it ends the region. | |
520 NEXT-FN should return nil if there are no annotations after point. | |
521 | |
522 The basic format of the TRANSLATIONS argument is described in the | |
523 documentation for the `format-annotate-region' function. There are some | |
524 additional things to keep in mind for decoding, though: | |
525 | |
526 When an annotation is found, the TRANSLATIONS list is searched for a | |
527 text-property name and value that corresponds to that annotation. If the | |
528 text-property has several annotations associated with it, it will be used only | |
529 if the other annotations are also in effect at that point. The first match | |
530 found whose annotations are all present is used. | |
531 | |
532 The text property thus determined is set to the value over the region between | |
533 the opening and closing annotations. However, if the text-property name has a | |
534 non-nil `format-list-valued' property, then the value will be consed onto the | |
535 surrounding value of the property, rather than replacing that value. | |
536 | |
537 There are some special symbols that can be used in the \"property\" slot of | |
538 the TRANSLATIONS list: PARAMETER and FUNCTION \(spelled in uppercase). | |
539 Annotations listed under the pseudo-property PARAMETER are considered to be | |
540 arguments of the immediately surrounding annotation; the text between the | |
541 opening and closing parameter annotations is deleted from the buffer but saved | |
542 as a string. The surrounding annotation should be listed under the | |
543 pseudo-property FUNCTION. Instead of inserting a text-property for this | |
544 annotation, the function listed in the VALUE slot is called to make whatever | |
545 changes are appropriate. The function's first two arguments are the START and | |
546 END locations, and the rest of the arguments are any PARAMETERs found in that | |
547 region. | |
548 | |
549 Any annotations that are found by NEXT-FN but not defined by TRANSLATIONS | |
550 are saved as values of the `unknown' text-property \(which is list-valued). | |
551 The TRANSLATIONS list should usually contain an entry of the form | |
552 \(unknown \(nil format-annotate-value)) | |
553 to write these unknown annotations back into the file." | |
554 (save-excursion | |
555 (save-restriction | |
556 (narrow-to-region (point-min) to) | |
557 (goto-char from) | |
558 (let (next open-ans todo | |
559 ;; loc | |
560 unknown-ans) | |
561 (while (setq next (funcall next-fn)) | |
562 (let* ((loc (nth 0 next)) | |
563 (end (nth 1 next)) | |
564 (name (nth 2 next)) | |
565 (positive (nth 3 next)) | |
566 (found nil)) | |
567 | |
568 ;; Delete the annotation | |
569 (delete-region loc end) | |
570 (cond | |
571 ;; Positive annotations are stacked, remembering location | |
572 (positive (setq open-ans (cons `(,name ((,loc . nil))) open-ans))) | |
573 ;; It is a negative annotation: | |
574 ;; Close the top annotation & add its text property. | |
575 ;; If the file's nesting is messed up, the close might not match | |
576 ;; the top thing on the open-annotations stack. | |
577 ;; If no matching annotation is open, just ignore the close. | |
578 ((not (assoc name open-ans)) | |
579 (message "Extra closing annotation (%s) in file" name)) | |
580 ;; If one is open, but not on the top of the stack, close | |
581 ;; the things in between as well. Set `found' when the real | |
582 ;; one is closed. | |
583 (t | |
584 (while (not found) | |
585 (let* ((top (car open-ans)) ; first on stack: should match. | |
586 (top-name (car top)) ; text property name | |
587 (top-extents (nth 1 top)) ; property regions | |
588 (params (cdr (cdr top))) ; parameters | |
589 (aalist translations) | |
590 (matched nil)) | |
591 (if (equal name top-name) | |
592 (setq found t) | |
593 (message "Improper nesting in file.")) | |
594 ;; Look through property names in TRANSLATIONS | |
595 (while aalist | |
596 (let ((prop (car (car aalist))) | |
597 (alist (cdr (car aalist)))) | |
598 ;; And look through values for each property | |
599 (while alist | |
600 (let ((value (car (car alist))) | |
601 (ans (cdr (car alist)))) | |
602 (if (member top-name ans) | |
603 ;; This annotation is listed, but still have to | |
604 ;; check if multiple annotations are satisfied | |
605 (if (member nil (mapcar (lambda (r) | |
606 (assoc r open-ans)) | |
607 ans)) | |
608 nil ; multiple ans not satisfied | |
609 ;; If there are multiple annotations going | |
610 ;; into one text property, split up the other | |
611 ;; annotations so they apply individually to | |
612 ;; the other regions. | |
613 (setcdr (car top-extents) loc) | |
614 (let ((to-split ans) this-one extents) | |
615 (while to-split | |
616 (setq this-one | |
617 (assoc (car to-split) open-ans) | |
618 extents (nth 1 this-one)) | |
619 (if (not (eq this-one top)) | |
620 (setcar (cdr this-one) | |
621 (format-subtract-regions | |
622 extents top-extents))) | |
623 (setq to-split (cdr to-split)))) | |
624 ;; Set loop variables to nil so loop | |
625 ;; will exit. | |
626 (setq alist nil aalist nil matched t | |
627 ;; pop annotation off stack. | |
628 open-ans (cdr open-ans)) | |
629 (let ((extents top-extents) | |
630 (start (car (car top-extents))) | |
631 (loc (cdr (car top-extents)))) | |
632 (while extents | |
633 (cond | |
634 ;; Check for pseudo-properties | |
635 ((eq prop 'PARAMETER) | |
636 ;; A parameter of the top open ann: | |
637 ;; delete text and use as arg. | |
638 (if open-ans | |
639 ;; (If nothing open, discard). | |
640 (setq open-ans | |
641 (cons | |
642 (append (car open-ans) | |
643 (list | |
644 (buffer-substring | |
645 start loc))) | |
646 (cdr open-ans)))) | |
647 (delete-region start loc)) | |
648 ((eq prop 'FUNCTION) | |
649 ;; Not a property, but a function. | |
650 (let ((rtn | |
651 (apply value start loc params))) | |
652 (if rtn (setq todo (cons rtn todo))))) | |
653 (t | |
654 ;; Normal property/value pair | |
655 (setq todo | |
656 (cons (list start loc prop value) | |
657 todo)))) | |
658 (setq extents (cdr extents) | |
659 start (car (car extents)) | |
660 loc (cdr (car extents)))))))) | |
661 (setq alist (cdr alist)))) | |
662 (setq aalist (cdr aalist))) | |
663 (unless matched | |
664 ;; Didn't find any match for the annotation: | |
665 ;; Store as value of text-property `unknown'. | |
666 (setcdr (car top-extents) loc) | |
667 (let ((extents top-extents) | |
668 (start (car (car top-extents))) | |
669 (loc (cdr (car top-extents)))) | |
670 (while extents | |
671 (setq open-ans (cdr open-ans) | |
672 todo (cons (list start loc 'unknown top-name) | |
673 todo) | |
674 unknown-ans (cons name unknown-ans) | |
675 extents (cdr extents) | |
676 start (car (car extents)) | |
677 loc (cdr (car extents)))))))))))) | |
678 | |
679 ;; Once entire file has been scanned, add the properties. | |
680 (while todo | |
681 (let* ((item (car todo)) | |
682 (from (nth 0 item)) | |
683 (to (nth 1 item)) | |
684 (prop (nth 2 item)) | |
685 (val (nth 3 item))) | |
686 | |
687 (if (numberp val) ; add to ambient value if numeric | |
688 (format-property-increment-region from to prop val 0) | |
689 (put-text-property | |
690 from to prop | |
691 (cond ((get prop 'format-list-valued) ; value gets consed onto | |
692 ; list-valued properties | |
693 (let ((prev (get-text-property from prop))) | |
694 (cons val (if (listp prev) prev (list prev))))) | |
695 (t val))))) ; normally, just set to val. | |
696 (setq todo (cdr todo))) | |
697 | |
698 (if unknown-ans | |
699 (message "Unknown annotations: %s" unknown-ans)))))) | |
700 | |
701 (defun format-subtract-regions (minu subtra) | |
702 "Remove the regions in SUBTRAHEND from the regions in MINUEND. A region | |
703 is a dotted pair (from . to). Both parameters are lists of regions. Each | |
704 list must contain nonoverlapping, noncontiguous regions, in descending | |
705 order. The result is also nonoverlapping, noncontiguous, and in descending | |
706 order. The first element of MINUEND can have a cdr of nil, indicating that | |
707 the end of that region is not yet known." | |
708 (let* ((minuend (copy-alist minu)) | |
709 (subtrahend (copy-alist subtra)) | |
710 (m (car minuend)) | |
711 (s (car subtrahend)) | |
712 results) | |
713 (while (and minuend subtrahend) | |
714 (cond | |
715 ;; The minuend starts after the subtrahend ends; keep it. | |
716 ((> (car m) (cdr s)) | |
717 (setq results (cons m results) | |
718 minuend (cdr minuend) | |
719 m (car minuend))) | |
720 ;; The minuend extends beyond the end of the subtrahend. Chop it off. | |
721 ((or (null (cdr m)) (> (cdr m) (cdr s))) | |
722 (setq results (cons (cons (1+ (cdr s)) (cdr m)) results)) | |
723 (setcdr m (cdr s))) | |
724 ;; The subtrahend starts after the minuend ends; throw it away. | |
725 ((< (cdr m) (car s)) | |
726 (setq subtrahend (cdr subtrahend) s (car subtrahend))) | |
727 ;; The subtrahend extends beyond the end of the minuend. Chop it off. | |
728 (t ;(<= (cdr m) (cdr s))) | |
729 (if (>= (car m) (car s)) | |
730 (setq minuend (cdr minuend) m (car minuend)) | |
731 (setcdr m (1- (car s))) | |
732 (setq subtrahend (cdr subtrahend) s (car subtrahend)))))) | |
733 (nconc (nreverse results) minuend))) | |
734 | |
735 ;; This should probably go somewhere other than format.el. Then again, | |
736 ;; indent.el has alter-text-property. NOTE: We can also use | |
737 ;; next-single-property-change instead of text-property-not-all, but then | |
738 ;; we have to see if we passed TO. | |
739 (defun format-property-increment-region (from to prop delta default) | |
740 "Increment property PROP over the region between FROM and TO by the | |
741 amount DELTA (which may be negative). If property PROP is nil anywhere | |
742 in the region, it is treated as though it were DEFAULT." | |
743 (let ((cur from) val newval next) | |
744 (while cur | |
745 (setq val (get-text-property cur prop) | |
746 newval (+ (or val default) delta) | |
747 next (text-property-not-all cur to prop val)) | |
748 (put-text-property cur (or next to) prop newval) | |
749 (setq cur next)))) | |
750 | |
751 ;;; | |
752 ;;; Encoding | |
753 ;;; | |
754 | |
755 (defun format-insert-annotations (list &optional offset) | |
756 "Apply list of annotations to buffer as `write-region' would. | |
757 Inserts each element of the given LIST of buffer annotations at its | |
758 appropriate place. Use second arg OFFSET if the annotations' locations are | |
759 not relative to the beginning of the buffer: annotations will be inserted | |
760 at their location-OFFSET+1 \(ie, the offset is treated as the character number | |
761 of the first character in the buffer)." | |
762 (if (not offset) | |
763 (setq offset 0) | |
764 (setq offset (1- offset))) | |
765 (let ((l (reverse list))) | |
766 (while l | |
767 (goto-char (- (car (car l)) offset)) | |
768 (insert (cdr (car l))) | |
769 (setq l (cdr l))))) | |
770 | |
771 (defun format-annotate-value (old new) | |
772 "Return OLD and NEW as a \(close . open) annotation pair. | |
773 Useful as a default function for TRANSLATIONS alist when the value of the text | |
774 property is the name of the annotation that you want to use, as it is for the | |
775 `unknown' text property." | |
776 (cons (if old (list old)) | |
777 (if new (list new)))) | |
778 | |
779 (defun format-annotate-region (from to trans format-fn ignore) | |
780 "Generate annotations for text properties in the region. | |
781 Searches for changes between FROM and TO, and describes them with a list of | |
782 annotations as defined by alist TRANSLATIONS and FORMAT-FN. IGNORE lists text | |
783 properties not to consider; any text properties that are neither ignored nor | |
784 listed in TRANSLATIONS are warned about. | |
785 If you actually want to modify the region, give the return value of this | |
786 function to `format-insert-annotations'. | |
787 | |
788 Format of the TRANSLATIONS argument: | |
789 | |
790 Each element is a list whose car is a PROPERTY, and the following | |
791 elements are VALUES of that property followed by the names of zero or more | |
792 ANNOTATIONS. Whenever the property takes on that value, the annotations | |
793 \(as formatted by FORMAT-FN) are inserted into the file. | |
794 When the property stops having that value, the matching negated annotation | |
795 will be inserted \(it may actually be closed earlier and reopened, if | |
796 necessary, to keep proper nesting). | |
797 | |
798 If the property's value is a list, then each element of the list is dealt with | |
799 separately. | |
800 | |
801 If a VALUE is numeric, then it is assumed that there is a single annotation | |
802 and each occurrence of it increments the value of the property by that number. | |
803 Thus, given the entry \(left-margin \(4 \"indent\")), if the left margin | |
804 changes from 4 to 12, two <indent> annotations will be generated. | |
805 | |
806 If the VALUE is nil, then instead of annotations, a function should be | |
807 specified. This function is used as a default: it is called for all | |
808 transitions not explicitly listed in the table. The function is called with | |
809 two arguments, the OLD and NEW values of the property. It should return | |
810 lists of annotations like `format-annotate-location' does. | |
811 | |
812 The same structure can be used in reverse for reading files." | |
813 (let ((all-ans nil) ; All annotations - becomes return value | |
814 (open-ans nil) ; Annotations not yet closed | |
815 (loc nil) ; Current location | |
816 (not-found nil)) ; Properties that couldn't be saved | |
817 (while (or (null loc) | |
818 (and (setq loc (next-property-change loc nil to)) | |
819 (< loc to))) | |
820 (or loc (setq loc from)) | |
821 (let* ((ans (format-annotate-location loc (= loc from) ignore trans)) | |
822 (neg-ans (format-reorder (aref ans 0) open-ans)) | |
823 (pos-ans (aref ans 1)) | |
824 (ignored (aref ans 2))) | |
825 (setq not-found (append ignored not-found) | |
826 ignore (append ignored ignore)) | |
827 ;; First do the negative (closing) annotations | |
828 (while neg-ans | |
829 ;; Check if it's missing. This can happen (eg, a numeric property | |
830 ;; going negative can generate closing annotations before there are | |
831 ;; any open). Warn user & ignore. | |
832 (if (not (member (car neg-ans) open-ans)) | |
833 (message "Can't close %s: not open." (car neg-ans)) | |
834 (while (not (equal (car neg-ans) (car open-ans))) | |
835 ;; To close anno. N, need to first close ans 1 to N-1, | |
836 ;; remembering to re-open them later. | |
837 (setq pos-ans (cons (car open-ans) pos-ans)) | |
838 (setq all-ans | |
839 (cons (cons loc (funcall format-fn (car open-ans) nil)) | |
840 all-ans)) | |
841 (setq open-ans (cdr open-ans))) | |
842 ;; Now remove the one we're really interested in from open list. | |
843 (setq open-ans (cdr open-ans)) | |
844 ;; And put the closing annotation here. | |
845 (setq all-ans | |
846 (cons (cons loc (funcall format-fn (car neg-ans) nil)) | |
847 all-ans))) | |
848 (setq neg-ans (cdr neg-ans))) | |
849 ;; Now deal with positive (opening) annotations | |
850 (let ( ; (p pos-ans) | |
851 ) | |
852 (while pos-ans | |
853 (setq open-ans (cons (car pos-ans) open-ans)) | |
854 (setq all-ans | |
855 (cons (cons loc (funcall format-fn (car pos-ans) t)) | |
856 all-ans)) | |
857 (setq pos-ans (cdr pos-ans)))))) | |
858 | |
859 ;; Close any annotations still open | |
860 (while open-ans | |
861 (setq all-ans | |
862 (cons (cons to (funcall format-fn (car open-ans) nil)) | |
863 all-ans)) | |
864 (setq open-ans (cdr open-ans))) | |
865 (if not-found | |
866 (message "These text properties could not be saved:\n %s" | |
867 not-found)) | |
868 (nreverse all-ans))) | |
869 | |
870 ;;; Internal functions for format-annotate-region. | |
871 | |
872 (defun format-annotate-location (loc all ignore trans) | |
873 "Return annotation(s) needed at LOCATION. | |
874 This includes any properties that change between LOC-1 and LOC. | |
875 If ALL is true, don't look at previous location, but generate annotations for | |
876 all non-nil properties. | |
877 Third argument IGNORE is a list of text-properties not to consider. | |
878 | |
879 Return value is a vector of 3 elements: | |
880 1. List of names of the annotations to close | |
881 2. List of the names of annotations to open. | |
882 3. List of properties that were ignored or couldn't be annotated." | |
883 (let* ((prev-loc (1- loc)) | |
884 (before-plist (if all nil (text-properties-at prev-loc))) | |
885 (after-plist (text-properties-at loc)) | |
886 p negatives positives prop props not-found) | |
887 ;; make list of all property names involved | |
888 (setq p before-plist) | |
889 (while p | |
890 (if (not (memq (car p) props)) | |
891 (setq props (cons (car p) props))) | |
892 (setq p (cdr (cdr p)))) | |
893 (setq p after-plist) | |
894 (while p | |
895 (if (not (memq (car p) props)) | |
896 (setq props (cons (car p) props))) | |
897 (setq p (cdr (cdr p)))) | |
898 | |
899 (while props | |
900 (setq prop (car props) | |
901 props (cdr props)) | |
902 (if (memq prop ignore) | |
903 nil ; If it's been ignored before, ignore it now. | |
904 (let ((before (if all nil (car (cdr (memq prop before-plist))))) | |
905 (after (car (cdr (memq prop after-plist))))) | |
906 (if (equal before after) | |
907 nil ; no change; ignore | |
908 (let ((result (format-annotate-single-property-change | |
909 prop before after trans))) | |
910 (if (not result) | |
911 (setq not-found (cons prop not-found)) | |
912 (setq negatives (nconc negatives (car result)) | |
913 positives (nconc positives (cdr result))))))))) | |
914 (vector negatives positives not-found))) | |
915 | |
916 (defun format-annotate-single-property-change (prop old new trans) | |
917 "Return annotations for PROPERTY changing from OLD to NEW. | |
918 These are searched for in the TRANSLATIONS alist. | |
919 If NEW does not appear in the list, but there is a default function, then that | |
920 function is called. | |
921 Annotations to open and to close are returned as a dotted pair." | |
922 (let ((prop-alist (cdr (assoc prop trans))) | |
923 ;; default | |
924 ) | |
925 (if (not prop-alist) | |
926 nil | |
927 ;; If either old or new is a list, have to treat both that way. | |
928 (if (or (consp old) (consp new)) | |
929 (let* ((old (if (listp old) old (list old))) | |
930 (new (if (listp new) new (list new))) | |
931 ;; (tail (format-common-tail old new)) | |
932 close open) | |
933 (while old | |
934 (setq close | |
935 (append (car (format-annotate-atomic-property-change | |
936 prop-alist (car old) nil)) | |
937 close) | |
938 old (cdr old))) | |
939 (while new | |
940 (setq open | |
941 (append (cdr (format-annotate-atomic-property-change | |
942 prop-alist nil (car new))) | |
943 open) | |
944 new (cdr new))) | |
945 (format-make-relatively-unique close open)) | |
946 (format-annotate-atomic-property-change prop-alist old new))))) | |
947 | |
948 (defun format-annotate-atomic-property-change (prop-alist old new) | |
949 "Internal function annotate a single property change. | |
950 PROP-ALIST is the relevant segment of a TRANSLATIONS list. | |
951 OLD and NEW are the values." | |
952 (let (num-ann) | |
953 ;; If old and new values are numbers, | |
954 ;; look for a number in PROP-ALIST. | |
955 (if (and (or (null old) (numberp old)) | |
956 (or (null new) (numberp new))) | |
957 (progn | |
958 (setq num-ann prop-alist) | |
959 (while (and num-ann (not (numberp (car (car num-ann))))) | |
960 (setq num-ann (cdr num-ann))))) | |
961 (if num-ann | |
962 ;; Numerical annotation - use difference | |
963 (progn | |
964 ;; If property is numeric, nil means 0 | |
965 (cond ((and (numberp old) (null new)) | |
966 (setq new 0)) | |
967 ((and (numberp new) (null old)) | |
968 (setq old 0))) | |
969 | |
970 (let* ((entry (car num-ann)) | |
971 (increment (car entry)) | |
972 (n (ceiling (/ (float (- new old)) (float increment)))) | |
973 (anno (car (cdr entry)))) | |
974 (if (> n 0) | |
975 (cons nil (make-list n anno)) | |
976 (cons (make-list (- n) anno) nil)))) | |
977 | |
978 ;; Standard annotation | |
979 (let ((close (and old (cdr (assoc old prop-alist)))) | |
980 (open (and new (cdr (assoc new prop-alist))))) | |
981 (if (or close open) | |
982 (format-make-relatively-unique close open) | |
983 ;; Call "Default" function, if any | |
984 (let ((default (assq nil prop-alist))) | |
985 (if default | |
986 (funcall (car (cdr default)) old new)))))))) | |
987 | |
988 ;;; format.el ends here |