1 ;;; format.el --- read and save files in multiple formats
3 ;; Copyright (c) 1994, 1995, 1997, 1999 Free Software Foundation
5 ;; Author: Boris Goldowsky <boris@gnu.org>
7 ;; This file is part of GNU Emacs.
9 ;; GNU Emacs is free software; you can redistribute it and/or modify
10 ;; it under the terms of the GNU General Public License as published by
11 ;; the Free Software Foundation; either version 2, or (at your option)
14 ;; GNU Emacs is distributed in the hope that it will be useful,
15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 ;; GNU General Public License for more details.
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with GNU Emacs; see the file COPYING. If not, write to the
21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 ;; Boston, MA 02111-1307, USA.
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.
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'.
39 ;; Auto-save files are normally created in the same format as the visited
40 ;; file, but the variable `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).
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'.
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.
64 (put 'buffer-file-format
'permanent-local t
)
67 '((text/enriched
"Extended MIME text/enriched format."
68 "Content-[Tt]ype:[ \t]*text/enriched"
69 enriched-decode enriched-encode t enriched-mode
)
70 (plain "ISO 8859-1 standard format, no text properties."
71 ;; Plain only exists so that there is an obvious neutral choice in
72 ;; the completion list.
74 (ibm "IBM Code Page 850 (DOS)"
75 nil
; The original "1\\(^\\)" is obscure.
76 "recode -f ibm-pc:latin1" "recode -f latin1:ibm-pc" t nil
)
77 (mac "Apple Macintosh"
79 "recode -f mac:latin1" "recode -f latin1:mac" t nil
)
82 "recode -f roman8:latin1" "recode -f latin1:roman8" t nil
)
85 iso-tex2iso iso-iso2tex t nil
)
86 (gtex "German TeX (encoding)"
88 iso-gtex2iso iso-iso2gtex t nil
)
89 (html "HTML/SGML \"ISO 8879:1986//ENTITIES Added Latin 1//EN\" (encoding)"
91 iso-sgml2iso iso-iso2sgml t nil
)
94 "tr a-mn-z n-za-m" "tr a-mn-z n-za-m" t nil
)
95 (duden "Duden Ersatzdarstellung"
97 "diac" iso-iso2duden t nil
)
98 (de646 "German ASCII (ISO 646)"
100 "recode -f iso646-ge:latin1" "recode -f latin1:iso646-ge" t nil
)
103 iso-german iso-cvt-read-only t nil
)
106 iso-spanish iso-cvt-read-only t nil
))
107 "List of information about understood file formats.
108 Elements are of the form \(NAME DOC-STR REGEXP FROM-FN TO-FN MODIFY MODE-FN).
110 NAME is a symbol, which is stored in `buffer-file-format'.
112 DOC-STR should be a single line providing more information about the
113 format. It is currently unused, but in the future will be shown to
114 the user if they ask for more information.
116 REGEXP is a regular expression to match against the beginning of the file;
117 it should match only files in that format. Use nil to avoid
118 matching at all for formats for which this isn't appropriate to
119 require explicit encoding/decoding.
121 FROM-FN is called to decode files in that format; it gets two args, BEGIN
122 and END, and can make any modifications it likes, returning the new
123 end. It must make sure that the beginning of the file no longer
124 matches REGEXP, or else it will get called again.
125 Alternatively, FROM-FN can be a string, which specifies a shell command
126 (including options) to be used as a filter to perform the conversion.
128 TO-FN is called to encode a region into that format; it is passed three
129 arguments: BEGIN, END, and BUFFER. BUFFER is the original buffer that
130 the data being written came from, which the function could use, for
131 example, to find the values of local variables. TO-FN should either
132 return a list of annotations like `write-region-annotate-functions',
133 or modify the region and return the new end.
134 Alternatively, TO-FN can be a string, which specifies a shell command
135 (including options) to be used as a filter to perform the conversion.
137 MODIFY, if non-nil, means the TO-FN wants to modify the region. If nil,
138 TO-FN will not make any changes but will instead return a list of
141 MODE-FN, if specified, is called when visiting a file with that format.")
143 ;;; Basic Functions (called from Lisp)
145 (defun format-encode-run-method (method from to
&optional buffer
)
146 "Translate using function or shell script METHOD the text from FROM to TO.
147 If METHOD is a string, it is a shell command;
148 otherwise, it should be a Lisp function.
149 BUFFER should be the buffer that the output originally came from."
151 (let ((error-buff (get-buffer-create "*Format Errors*"))
152 (coding-system-for-read 'no-conversion
)
154 (with-current-buffer error-buff
157 (if (and (zerop (save-window-excursion
158 (shell-command-on-region from to method t t
160 ;; gzip gives zero exit status with bad args, for instance.
161 (zerop (with-current-buffer error-buff
163 (bury-buffer error-buff
)
164 (switch-to-buffer-other-window error-buff
)
165 (error "Format encoding failed")))
166 (funcall method from to buffer
)))
168 (defun format-decode-run-method (method from to
&optional buffer
)
169 "Decode using function or shell script METHOD the text from FROM to TO.
170 If METHOD is a string, it is a shell command; otherwise, it should be
171 a Lisp function. Decoding is done for the given BUFFER."
173 (let ((error-buff (get-buffer-create "*Format Errors*"))
174 (coding-system-for-write 'no-conversion
)
176 (with-current-buffer error-buff
179 ;; We should perhaps go via a temporary buffer and copy it
180 ;; back, in case of errors.
181 (if (and (zerop (save-window-excursion
182 (shell-command-on-region (point-min) (point-max)
185 ;; gzip gives zero exit status with bad args, for instance.
186 (zerop (with-current-buffer error-buff
188 (bury-buffer error-buff
)
189 (switch-to-buffer-other-window error-buff
)
190 (error "Format decoding failed"))
192 (funcall method from to
)))
194 (defun format-annotate-function (format from to orig-buf format-count
)
195 "Return annotations for writing region as FORMAT.
196 FORMAT is a symbol naming one of the formats defined in `format-alist',
197 it must be a single symbol, not a list like `buffer-file-format'.
198 FROM and TO delimit the region to be operated on in the current buffer.
199 ORIG-BUF is the original buffer that the data came from.
201 FORMAT-COUNT is an integer specifying how many times this function has
202 been called in the process of decoding ORIG-BUF.
204 This function works like a function on `write-region-annotate-functions':
205 it either returns a list of annotations, or returns with a different buffer
206 current, which contains the modified text to write. In the latter case,
207 this function's value is nil.
209 For most purposes, consider using `format-encode-region' instead."
210 ;; This function is called by write-region (actually
211 ;; build_annotations) for each element of buffer-file-format.
212 (let* ((info (assq format format-alist
))
214 (modify (nth 5 info
)))
217 ;; To-function wants to modify region. Copy to safe place.
218 (let ((copy-buf (get-buffer-create (format " *Format Temp %d*"
220 (copy-to-buffer copy-buf from to
)
221 (set-buffer copy-buf
)
222 (format-insert-annotations write-region-annotations-so-far from
)
223 (format-encode-run-method to-fn
(point-min) (point-max) orig-buf
)
225 ;; Otherwise just call function, it will return annotations.
226 (funcall to-fn from to orig-buf
)))))
228 (defun format-decode (format length
&optional visit-flag
)
229 ;; This function is called by insert-file-contents whenever a file is read.
230 "Decode text from any known FORMAT.
231 FORMAT is a symbol appearing in `format-alist' or a list of such symbols,
232 or nil, in which case this function tries to guess the format of the data by
233 matching against the regular expressions in `format-alist'. After a match is
234 found and the region decoded, the alist is searched again from the beginning
237 Second arg LENGTH is the number of characters following point to operate on.
238 If optional third arg VISIT-FLAG is true, set `buffer-file-format'
239 to the list of formats used, and call any mode functions defined for those
242 Returns the new length of the decoded region.
244 For most purposes, consider using `format-decode-region' instead."
245 (let ((mod (buffer-modified-p))
247 (end (+ (point) length
)))
250 ;; Don't record undo information for the decoding.
253 ;; Figure out which format it is in, remember list in `format'.
254 (let ((try format-alist
))
259 (if (and regexp
(looking-at regexp
)
260 (< (match-end 0) (+ begin length
)))
262 (setq format
(cons (car f
) format
))
265 (setq end
(format-decode-run-method (nth 3 f
) begin end
)))
266 ;; Call visit function if required
267 (if (and visit-flag
(nth 6 f
)) (funcall (nth 6 f
) 1))
268 ;; Safeguard against either of the functions changing pt.
270 ;; Rewind list to look for another format
271 (setq try format-alist
))
272 (setq try
(cdr try
))))))
273 ;; Deal with given format(s)
274 (or (listp format
) (setq format
(list format
)))
277 (or (setq f
(assq (car do
) format-alist
))
278 (error "Unknown format" (car do
)))
281 (setq end
(format-decode-run-method (nth 3 f
) begin end
)))
282 ;; Call visit function if required
283 (if (and visit-flag
(nth 6 f
)) (funcall (nth 6 f
) 1))
284 (setq do
(cdr do
)))))
286 (setq buffer-file-format format
)))
288 (set-buffer-modified-p mod
))
290 ;; Return new length of region
294 ;;; Interactive functions & entry points
297 (defun format-decode-buffer (&optional format
)
298 "Translate the buffer from some FORMAT.
299 If the format is not specified, this function attempts to guess.
300 `buffer-file-format' is set to the format used, and any mode-functions
301 for the format are called."
303 (list (format-read "Translate buffer from format (default: guess): ")))
305 (goto-char (point-min))
306 (format-decode format
(buffer-size) t
)))
308 (defun format-decode-region (from to
&optional format
)
309 "Decode the region from some format.
310 Arg FORMAT is optional; if omitted the format will be determined by looking
311 for identifying regular expressions at the beginning of the region."
313 (list (region-beginning) (region-end)
314 (format-read "Translate region from format (default: guess): ")))
317 (format-decode format
(- to from
) nil
)))
319 (defun format-encode-buffer (&optional format
)
320 "Translate the buffer into FORMAT.
321 FORMAT defaults to `buffer-file-format'. It is a symbol naming one of the
322 formats defined in `format-alist', or a list of such symbols."
324 (list (format-read (format "Translate buffer to format (default %s): "
325 buffer-file-format
))))
326 (format-encode-region (point-min) (point-max) format
))
328 (defun format-encode-region (beg end
&optional format
)
329 "Translate the region into some FORMAT.
330 FORMAT defaults to `buffer-file-format', it is a symbol naming
331 one of the formats defined in `format-alist', or a list of such symbols."
333 (list (region-beginning) (region-end)
334 (format-read (format "Translate region to format (default %s): "
335 buffer-file-format
))))
336 (if (null format
) (setq format buffer-file-format
))
337 (if (symbolp format
) (setq format
(list format
)))
340 (let ((cur-buf (current-buffer))
341 (end (point-marker)))
343 (let* ((info (assq (car format
) format-alist
))
345 (modify (nth 5 info
))
349 (setq end
(format-encode-run-method to-fn beg end
351 (format-insert-annotations
352 (funcall to-fn beg end
(current-buffer)))))
353 (setq format
(cdr format
)))))))
355 (defun format-write-file (filename format
)
356 "Write current buffer into file FILENAME using some FORMAT.
357 Makes buffer visit that file and sets the format as the default for future
358 saves. If the buffer is already visiting a file, you can specify a directory
359 name as FILENAME, to write a file of the same old name in that directory."
361 ;; Same interactive spec as write-file, plus format question.
362 (let* ((file (if buffer-file-name
363 (read-file-name "Write file: "
365 (read-file-name "Write file: "
366 (cdr (assq 'default-directory
367 (buffer-local-variables)))
368 nil nil
(buffer-name))))
369 (fmt (format-read (format "Write file `%s' in format: "
370 (file-name-nondirectory file
)))))
372 (setq buffer-file-format format
)
373 (write-file filename
))
375 (defun format-find-file (filename format
)
376 "Find the file FILENAME using data format FORMAT.
377 If FORMAT is nil then do not do any format conversion."
379 ;; Same interactive spec as write-file, plus format question.
380 (let* ((file (read-file-name "Find file: "))
381 (fmt (format-read (format "Read file `%s' in format: "
382 (file-name-nondirectory file
)))))
384 (let ((format-alist nil
))
385 (find-file filename
))
387 (format-decode-buffer format
)))
389 (defun format-insert-file (filename format
&optional beg end
)
390 "Insert the contents of file FILENAME using data format FORMAT.
391 If FORMAT is nil then do not do any format conversion.
392 The optional third and fourth arguments BEG and END specify
393 the part of the file to read.
395 The return value is like the value of `insert-file-contents':
396 a list (ABSOLUTE-FILE-NAME . SIZE)."
398 ;; Same interactive spec as write-file, plus format question.
399 (let* ((file (read-file-name "Find file: "))
400 (fmt (format-read (format "Read file `%s' in format: "
401 (file-name-nondirectory file
)))))
404 (let ((format-alist nil
))
405 (setq value
(insert-file-contents filename nil beg end
))
406 (setq size
(nth 1 value
)))
408 (setq size
(format-decode format size
)
409 value
(cons (car value
) size
)))
412 (defun format-read (&optional prompt
)
413 "Read and return the name of a format.
414 Return value is a list, like `buffer-file-format'; it may be nil.
415 Formats are defined in `format-alist'. Optional arg is the PROMPT to use."
416 (let* ((table (mapcar (lambda (x) (list (symbol-name (car x
))))
418 (ans (completing-read (or prompt
"Format: ") table nil t
)))
419 (if (not (equal "" ans
)) (list (intern ans
)))))
423 ;;; Below are some functions that may be useful in writing encoding and
424 ;;; decoding functions for use in format-alist.
427 (defun format-replace-strings (alist &optional reverse beg end
)
428 "Do multiple replacements on the buffer.
429 ALIST is a list of (from . to) pairs, which should be proper arguments to
430 `search-forward' and `replace-match' respectively.
431 Optional 2nd arg REVERSE, if non-nil, means the pairs are (to . from), so that
432 you can use the same list in both directions if it contains only literal
434 Optional args BEG and END specify a region of the buffer on which to operate."
437 (or beg
(setq beg
(point-min)))
438 (if end
(narrow-to-region (point-min) end
))
440 (let ((from (if reverse
(cdr (car alist
)) (car (car alist
))))
441 (to (if reverse
(car (car alist
)) (cdr (car alist
)))))
443 (while (search-forward from nil t
)
444 (goto-char (match-beginning 0))
446 (set-text-properties (- (point) (length to
)) (point)
447 (text-properties-at (point)))
448 (delete-region (point) (+ (point) (- (match-end 0)
449 (match-beginning 0)))))
450 (setq alist
(cdr alist
)))))))
452 ;;; Some list-manipulation functions that we need.
454 (defun format-delq-cons (cons list
)
455 "Remove the given CONS from LIST by side effect and return the new LIST.
456 Since CONS could be the first element of LIST, write
457 `\(setq foo \(format-delq-cons element foo))' to be sure of changing
462 (while (not (eq (cdr p
) cons
))
463 (if (null p
) (error "format-delq-cons: not an element."))
465 ;; Now (cdr p) is the cons to delete
466 (setcdr p
(cdr cons
))
469 (defun format-make-relatively-unique (a b
)
470 "Delete common elements of lists A and B, return as pair.
471 Compares using `equal'."
472 (let* ((acopy (copy-sequence a
))
473 (bcopy (copy-sequence b
))
476 (let ((dup (member (car tail
) bcopy
))
478 (if dup
(setq acopy
(format-delq-cons tail acopy
)
479 bcopy
(format-delq-cons dup bcopy
)))
483 (defun format-common-tail (a b
)
484 "Given two lists that have a common tail, return it.
485 Compares with `equal', and returns the part of A that is equal to the
486 equivalent part of B. If even the last items of the two are not equal,
488 (let ((la (length a
))
490 ;; Make sure they are the same length
492 (setq a
(nthcdr (- la lb
) a
))
493 (setq b
(nthcdr (- lb la
) b
))))
494 (while (not (equal a b
))
499 (defun format-proper-list-p (list)
500 "Return t if LIST is a proper list.
501 A proper list is a list ending with a nil cdr, not with an atom "
504 (setq list
(cdr list
)))
507 (defun format-reorder (items order
)
508 "Arrange ITEMS to following partial ORDER.
509 Elements of ITEMS equal to elements of ORDER will be rearranged to follow the
510 ORDER. Unmatched items will go last."
512 (let ((item (member (car order
) items
)))
515 (format-reorder (format-delq-cons item items
)
517 (format-reorder items
(cdr order
))))
520 (put 'face
'format-list-valued t
) ; These text-properties take values
521 (put 'unknown
'format-list-valued t
) ; that are lists, the elements of which
522 ; should be considered separately.
523 ; See format-deannotate-region and
524 ; format-annotate-region.
526 ;; This text property has list values, but they are treated atomically.
528 (put 'display
'format-list-atomic-p t
)
534 (defun format-deannotate-region (from to translations next-fn
)
535 "Translate annotations in the region into text properties.
536 This sets text properties between FROM to TO as directed by the
537 TRANSLATIONS and NEXT-FN arguments.
539 NEXT-FN is a function that searches forward from point for an annotation.
540 It should return a list of 4 elements: \(BEGIN END NAME POSITIVE). BEGIN and
541 END are buffer positions bounding the annotation, NAME is the name searched
542 for in TRANSLATIONS, and POSITIVE should be non-nil if this annotation marks
543 the beginning of a region with some property, or nil if it ends the region.
544 NEXT-FN should return nil if there are no annotations after point.
546 The basic format of the TRANSLATIONS argument is described in the
547 documentation for the `format-annotate-region' function. There are some
548 additional things to keep in mind for decoding, though:
550 When an annotation is found, the TRANSLATIONS list is searched for a
551 text-property name and value that corresponds to that annotation. If the
552 text-property has several annotations associated with it, it will be used only
553 if the other annotations are also in effect at that point. The first match
554 found whose annotations are all present is used.
556 The text property thus determined is set to the value over the region between
557 the opening and closing annotations. However, if the text-property name has a
558 non-nil `format-list-valued' property, then the value will be consed onto the
559 surrounding value of the property, rather than replacing that value.
561 There are some special symbols that can be used in the \"property\" slot of
562 the TRANSLATIONS list: PARAMETER and FUNCTION \(spelled in uppercase).
563 Annotations listed under the pseudo-property PARAMETER are considered to be
564 arguments of the immediately surrounding annotation; the text between the
565 opening and closing parameter annotations is deleted from the buffer but saved
566 as a string. The surrounding annotation should be listed under the
567 pseudo-property FUNCTION. Instead of inserting a text-property for this
568 annotation, the function listed in the VALUE slot is called to make whatever
569 changes are appropriate. The function's first two arguments are the START and
570 END locations, and the rest of the arguments are any PARAMETERs found in that
573 Any annotations that are found by NEXT-FN but not defined by TRANSLATIONS
574 are saved as values of the `unknown' text-property \(which is list-valued).
575 The TRANSLATIONS list should usually contain an entry of the form
576 \(unknown \(nil format-annotate-value))
577 to write these unknown annotations back into the file."
580 (narrow-to-region (point-min) to
)
582 (let (next open-ans todo loc unknown-ans
)
583 (while (setq next
(funcall next-fn
))
584 (let* ((loc (nth 0 next
))
587 (positive (nth 3 next
))
590 ;; Delete the annotation
591 (delete-region loc end
)
593 ;; Positive annotations are stacked, remembering location
594 (positive (setq open-ans
(cons `(,name
((,loc . nil
))) open-ans
)))
595 ;; It is a negative annotation:
596 ;; Close the top annotation & add its text property.
597 ;; If the file's nesting is messed up, the close might not match
598 ;; the top thing on the open-annotations stack.
599 ;; If no matching annotation is open, just ignore the close.
600 ((not (assoc name open-ans
))
601 (message "Extra closing annotation (%s) in file" name
))
602 ;; If one is open, but not on the top of the stack, close
603 ;; the things in between as well. Set `found' when the real
607 (let* ((top (car open-ans
)) ; first on stack: should match.
608 (top-name (car top
)) ; text property name
609 (top-extents (nth 1 top
)) ; property regions
610 (params (cdr (cdr top
))) ; parameters
611 (aalist translations
)
613 (if (equal name top-name
)
615 (message "Improper nesting in file."))
616 ;; Look through property names in TRANSLATIONS
618 (let ((prop (car (car aalist
)))
619 (alist (cdr (car aalist
))))
620 ;; And look through values for each property
622 (let ((value (car (car alist
)))
623 (ans (cdr (car alist
))))
624 (if (member top-name ans
)
625 ;; This annotation is listed, but still have to
626 ;; check if multiple annotations are satisfied
627 (if (member nil
(mapcar (lambda (r)
630 nil
; multiple ans not satisfied
631 ;; If there are multiple annotations going
632 ;; into one text property, split up the other
633 ;; annotations so they apply individually to
634 ;; the other regions.
635 (setcdr (car top-extents
) loc
)
636 (let ((to-split ans
) this-one extents
)
639 (assoc (car to-split
) open-ans
)
640 extents
(nth 1 this-one
))
641 (if (not (eq this-one top
))
642 (setcar (cdr this-one
)
643 (format-subtract-regions
644 extents top-extents
)))
645 (setq to-split
(cdr to-split
))))
646 ;; Set loop variables to nil so loop
648 (setq alist nil aalist nil matched t
649 ;; pop annotation off stack.
650 open-ans
(cdr open-ans
))
651 (let ((extents top-extents
)
652 (start (car (car top-extents
)))
653 (loc (cdr (car top-extents
))))
656 ;; Check for pseudo-properties
657 ((eq prop
'PARAMETER
)
658 ;; A parameter of the top open ann:
659 ;; delete text and use as arg.
661 ;; (If nothing open, discard).
664 (append (car open-ans
)
669 (delete-region start loc
))
671 ;; Not a property, but a function.
673 (apply value start loc params
)))
674 (if rtn
(setq todo
(cons rtn todo
)))))
676 ;; Normal property/value pair
678 (cons (list start loc prop value
)
680 (setq extents
(cdr extents
)
681 start
(car (car extents
))
682 loc
(cdr (car extents
))))))))
683 (setq alist
(cdr alist
))))
684 (setq aalist
(cdr aalist
)))
686 ;; Didn't find any match for the annotation:
687 ;; Store as value of text-property `unknown'.
688 (let ((extents top-extents
)
689 (start (car (car top-extents
)))
690 (loc (or (cdr (car top-extents
)) loc
)))
692 (setq open-ans
(cdr open-ans
)
693 todo
(cons (list start loc
'unknown top-name
)
695 unknown-ans
(cons name unknown-ans
)
696 extents
(cdr extents
)
697 start
(car (car extents
))
698 loc
(cdr (car extents
))))))))))))
700 ;; Once entire file has been scanned, add the properties.
702 (let* ((item (car todo
))
708 (if (numberp val
) ; add to ambient value if numeric
709 (format-property-increment-region from to prop val
0)
712 (cond ((get prop
'format-list-valued
) ; value gets consed onto
713 ; list-valued properties
714 (let ((prev (get-text-property from prop
)))
715 (cons val
(if (listp prev
) prev
(list prev
)))))
716 (t val
))))) ; normally, just set to val.
717 (setq todo
(cdr todo
)))
720 (message "Unknown annotations: %s" unknown-ans
))))))
722 (defun format-subtract-regions (minu subtra
)
723 "Remove from the regions in MINUend the regions in SUBTRAhend.
724 A region is a dotted pair (from . to). Both parameters are lists of
725 regions. Each list must contain nonoverlapping, noncontiguous
726 regions, in descending order. The result is also nonoverlapping,
727 noncontiguous, and in descending order. The first element of MINUEND
728 can have a cdr of nil, indicating that the end of that region is not
730 (let* ((minuend (copy-alist minu
))
731 (subtrahend (copy-alist subtra
))
735 (while (and minuend subtrahend
)
737 ;; The minuend starts after the subtrahend ends; keep it.
739 (setq results
(cons m results
)
740 minuend
(cdr minuend
)
742 ;; The minuend extends beyond the end of the subtrahend. Chop it off.
743 ((or (null (cdr m
)) (> (cdr m
) (cdr s
)))
744 (setq results
(cons (cons (1+ (cdr s
)) (cdr m
)) results
))
746 ;; The subtrahend starts after the minuend ends; throw it away.
748 (setq subtrahend
(cdr subtrahend
) s
(car subtrahend
)))
749 ;; The subtrahend extends beyond the end of the minuend. Chop it off.
750 (t ;(<= (cdr m) (cdr s)))
751 (if (>= (car m
) (car s
))
752 (setq minuend
(cdr minuend
) m
(car minuend
))
753 (setcdr m
(1- (car s
)))
754 (setq subtrahend
(cdr subtrahend
) s
(car subtrahend
))))))
755 (nconc (nreverse results
) minuend
)))
757 ;; This should probably go somewhere other than format.el. Then again,
758 ;; indent.el has alter-text-property. NOTE: We can also use
759 ;; next-single-property-change instead of text-property-not-all, but then
760 ;; we have to see if we passed TO.
761 (defun format-property-increment-region (from to prop delta default
)
762 "Over the region between FROM and TO increment property PROP by amount DELTA.
763 DELTA may be negative. If property PROP is nil anywhere
764 in the region, it is treated as though it were DEFAULT."
765 (let ((cur from
) val newval next
)
767 (setq val
(get-text-property cur prop
)
768 newval
(+ (or val default
) delta
)
769 next
(text-property-not-all cur to prop val
))
770 (put-text-property cur
(or next to
) prop newval
)
777 (defun format-insert-annotations (list &optional offset
)
778 "Apply list of annotations to buffer as `write-region' would.
779 Inserts each element of the given LIST of buffer annotations at its
780 appropriate place. Use second arg OFFSET if the annotations' locations are
781 not relative to the beginning of the buffer: annotations will be inserted
782 at their location-OFFSET+1 \(ie, the offset is treated as the character number
783 of the first character in the buffer)."
786 (setq offset
(1- offset
)))
787 (let ((l (reverse list
)))
789 (goto-char (- (car (car l
)) offset
))
790 (insert (cdr (car l
)))
793 (defun format-annotate-value (old new
)
794 "Return OLD and NEW as a \(close . open) annotation pair.
795 Useful as a default function for TRANSLATIONS alist when the value of the text
796 property is the name of the annotation that you want to use, as it is for the
797 `unknown' text property."
798 (cons (if old
(list old
))
799 (if new
(list new
))))
801 (defun format-annotate-region (from to translations format-fn ignore
)
802 "Generate annotations for text properties in the region.
803 Searches for changes between FROM and TO, and describes them with a list of
804 annotations as defined by alist TRANSLATIONS and FORMAT-FN. IGNORE lists text
805 properties not to consider; any text properties that are neither ignored nor
806 listed in TRANSLATIONS are warned about.
807 If you actually want to modify the region, give the return value of this
808 function to `format-insert-annotations'.
810 Format of the TRANSLATIONS argument:
812 Each element is a list whose car is a PROPERTY, and the following
813 elements are VALUES of that property followed by the names of zero or more
814 ANNOTATIONS. Whenever the property takes on that value, the annotations
815 \(as formatted by FORMAT-FN) are inserted into the file.
816 When the property stops having that value, the matching negated annotation
817 will be inserted \(it may actually be closed earlier and reopened, if
818 necessary, to keep proper nesting).
820 If the property's value is a list, then each element of the list is dealt with
823 If a VALUE is numeric, then it is assumed that there is a single annotation
824 and each occurrence of it increments the value of the property by that number.
825 Thus, given the entry \(left-margin \(4 \"indent\")), if the left margin
826 changes from 4 to 12, two <indent> annotations will be generated.
828 If the VALUE is nil, then instead of annotations, a function should be
829 specified. This function is used as a default: it is called for all
830 transitions not explicitly listed in the table. The function is called with
831 two arguments, the OLD and NEW values of the property. It should return
832 lists of annotations like `format-annotate-location' does.
834 The same structure can be used in reverse for reading files."
835 (let ((all-ans nil
) ; All annotations - becomes return value
836 (open-ans nil
) ; Annotations not yet closed
837 (loc nil
) ; Current location
838 (not-found nil
)) ; Properties that couldn't be saved
839 (while (or (null loc
)
840 (and (setq loc
(next-property-change loc nil to
))
842 (or loc
(setq loc from
))
843 (let* ((ans (format-annotate-location loc
(= loc from
) ignore translations
))
844 (neg-ans (format-reorder (aref ans
0) open-ans
))
845 (pos-ans (aref ans
1))
846 (ignored (aref ans
2)))
847 (setq not-found
(append ignored not-found
)
848 ignore
(append ignored ignore
))
849 ;; First do the negative (closing) annotations
851 ;; Check if it's missing. This can happen (eg, a numeric property
852 ;; going negative can generate closing annotations before there are
853 ;; any open). Warn user & ignore.
854 (if (not (member (car neg-ans
) open-ans
))
855 (message "Can't close %s: not open." (car neg-ans
))
856 (while (not (equal (car neg-ans
) (car open-ans
)))
857 ;; To close anno. N, need to first close ans 1 to N-1,
858 ;; remembering to re-open them later.
859 (setq pos-ans
(cons (car open-ans
) pos-ans
))
861 (cons (cons loc
(funcall format-fn
(car open-ans
) nil
))
863 (setq open-ans
(cdr open-ans
)))
864 ;; Now remove the one we're really interested in from open list.
865 (setq open-ans
(cdr open-ans
))
866 ;; And put the closing annotation here.
868 (cons (cons loc
(funcall format-fn
(car neg-ans
) nil
))
870 (setq neg-ans
(cdr neg-ans
)))
871 ;; Now deal with positive (opening) annotations
874 (setq open-ans
(cons (car pos-ans
) open-ans
))
876 (cons (cons loc
(funcall format-fn
(car pos-ans
) t
))
878 (setq pos-ans
(cdr pos-ans
))))))
880 ;; Close any annotations still open
883 (cons (cons to
(funcall format-fn
(car open-ans
) nil
))
885 (setq open-ans
(cdr open-ans
)))
887 (message "These text properties could not be saved:\n %s"
891 ;;; Internal functions for format-annotate-region.
893 (defun format-annotate-location (loc all ignore translations
)
894 "Return annotation(s) needed at location LOC.
895 This includes any properties that change between LOC-1 and LOC.
896 If ALL is true, don't look at previous location, but generate annotations for
897 all non-nil properties.
898 Third argument IGNORE is a list of text-properties not to consider.
899 Use the TRANSLATIONS alist.
901 Return value is a vector of 3 elements:
902 1. List of names of the annotations to close
903 2. List of the names of annotations to open.
904 3. List of properties that were ignored or couldn't be annotated."
905 (let* ((prev-loc (1- loc
))
906 (before-plist (if all nil
(text-properties-at prev-loc
)))
907 (after-plist (text-properties-at loc
))
908 p negatives positives prop props not-found
)
909 ;; make list of all property names involved
910 (setq p before-plist
)
912 (if (not (memq (car p
) props
))
913 (setq props
(cons (car p
) props
)))
914 (setq p
(cdr (cdr p
))))
917 (if (not (memq (car p
) props
))
918 (setq props
(cons (car p
) props
)))
919 (setq p
(cdr (cdr p
))))
922 (setq prop
(car props
)
924 (if (memq prop ignore
)
925 nil
; If it's been ignored before, ignore it now.
926 (let ((before (if all nil
(car (cdr (memq prop before-plist
)))))
927 (after (car (cdr (memq prop after-plist
)))))
928 (if (equal before after
)
929 nil
; no change; ignore
930 (let ((result (format-annotate-single-property-change
931 prop before after translations
)))
933 (setq not-found
(cons prop not-found
))
934 (setq negatives
(nconc negatives
(car result
))
935 positives
(nconc positives
(cdr result
)))))))))
936 (vector negatives positives not-found
)))
938 (defun format-annotate-single-property-change (prop old new trans
)
939 "Return annotations for property PROP changing from OLD to NEW.
940 These are searched for in the translations alist TRANS.
941 If NEW does not appear in the list, but there is a default function, then that
943 Annotations to open and to close are returned as a dotted pair."
944 (let ((prop-alist (cdr (assoc prop trans
)))
948 ;; If either old or new is a list, have to treat both that way.
949 (if (and (or (listp old
) (listp new
))
950 (not (get prop
'format-list-atomic-p
)))
951 (if (or (not (format-proper-list-p old
))
952 (not (format-proper-list-p new
)))
953 (format-annotate-atomic-property-change prop-alist old new
)
954 (let* ((old (if (listp old
) old
(list old
)))
955 (new (if (listp new
) new
(list new
)))
956 (tail (format-common-tail old new
))
960 (append (car (format-annotate-atomic-property-change
961 prop-alist
(car old
) nil
))
966 (append (cdr (format-annotate-atomic-property-change
967 prop-alist nil
(car new
)))
970 (format-make-relatively-unique close open
)))
971 (format-annotate-atomic-property-change prop-alist old new
)))))
973 (defun format-annotate-atomic-property-change (prop-alist old new
)
974 "Internal function annotate a single property change.
975 PROP-ALIST is the relevant segment of a TRANSLATIONS list.
976 OLD and NEW are the values."
978 ;; If old and new values are numbers,
979 ;; look for a number in PROP-ALIST.
980 (if (and (or (null old
) (numberp old
))
981 (or (null new
) (numberp new
)))
983 (setq num-ann prop-alist
)
984 (while (and num-ann
(not (numberp (car (car num-ann
)))))
985 (setq num-ann
(cdr num-ann
)))))
987 ;; Numerical annotation - use difference
989 ;; If property is numeric, nil means 0
990 (cond ((and (numberp old
) (null new
))
992 ((and (numberp new
) (null old
))
995 (let* ((entry (car num-ann
))
996 (increment (car entry
))
997 (n (ceiling (/ (float (- new old
)) (float increment
))))
998 (anno (car (cdr entry
))))
1000 (cons nil
(make-list n anno
))
1001 (cons (make-list (- n
) anno
) nil
))))
1003 ;; Standard annotation
1004 (let ((close (and old
(cdr (assoc old prop-alist
))))
1005 (open (and new
(cdr (assoc new prop-alist
)))))
1007 (format-make-relatively-unique close open
)
1008 ;; Call "Default" function, if any
1009 (let ((default (assq nil prop-alist
)))
1011 (funcall (car (cdr default
)) old new
))))))))
1015 ;;; format.el ends here