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1 | ;;; json.el --- JavaScript Object Notation parser / generator |
2 | ||
ba318903 | 3 | ;; Copyright (C) 2006-2014 Free Software Foundation, Inc. |
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4 | |
5 | ;; Author: Edward O'Connor <ted@oconnor.cx> | |
d72e9e92 | 6 | ;; Version: 1.4 |
02761f85 MO |
7 | ;; Keywords: convenience |
8 | ||
9 | ;; This file is part of GNU Emacs. | |
10 | ||
eb3fa2cf | 11 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
02761f85 | 12 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
13 | ;; the Free Software Foundation, either version 3 of the License, or |
14 | ;; (at your option) any later version. | |
02761f85 MO |
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 | |
eb3fa2cf | 22 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
02761f85 MO |
23 | |
24 | ;;; Commentary: | |
25 | ||
26 | ;; This is a library for parsing and generating JSON (JavaScript Object | |
27 | ;; Notation). | |
28 | ||
29 | ;; Learn all about JSON here: <URL:http://json.org/>. | |
30 | ||
31 | ;; The user-serviceable entry points for the parser are the functions | |
32 | ;; `json-read' and `json-read-from-string'. The encoder has a single | |
33 | ;; entry point, `json-encode'. | |
34 | ||
35 | ;; Since there are several natural representations of key-value pair | |
36 | ;; mappings in elisp (alist, plist, hash-table), `json-read' allows you | |
37 | ;; to specify which you'd prefer (see `json-object-type' and | |
38 | ;; `json-array-type'). | |
39 | ||
40 | ;; Similarly, since `false' and `null' are distinct in JSON, you can | |
41 | ;; distinguish them by binding `json-false' and `json-null' as desired. | |
42 | ||
43 | ;;; History: | |
44 | ||
45 | ;; 2006-03-11 - Initial version. | |
46 | ;; 2006-03-13 - Added JSON generation in addition to parsing. Various | |
47 | ;; other cleanups, bugfixes, and improvements. | |
48 | ;; 2006-12-29 - XEmacs support, from Aidan Kehoe <kehoea@parhasard.net>. | |
49 | ;; 2008-02-21 - Installed in GNU Emacs. | |
0bc06380 | 50 | ;; 2011-10-17 - Patch `json-alist-p' and `json-plist-p' to avoid recursion -tzz |
d72e9e92 | 51 | ;; 2012-10-25 - Added pretty-printed reformatting -Ryan Crum (ryan@ryancrum.org) |
02761f85 MO |
52 | |
53 | ;;; Code: | |
54 | ||
02761f85 MO |
55 | |
56 | ;; Compatibility code | |
57 | ||
58 | (defalias 'json-encode-char0 'encode-char) | |
59 | (defalias 'json-decode-char0 'decode-char) | |
60 | ||
61 | ||
62 | ;; Parameters | |
63 | ||
64 | (defvar json-object-type 'alist | |
65 | "Type to convert JSON objects to. | |
c8de140b | 66 | Must be one of `alist', `plist', or `hash-table'. Consider let-binding |
02761f85 MO |
67 | this around your call to `json-read' instead of `setq'ing it.") |
68 | ||
69 | (defvar json-array-type 'vector | |
70 | "Type to convert JSON arrays to. | |
c8de140b | 71 | Must be one of `vector' or `list'. Consider let-binding this around |
02761f85 MO |
72 | your call to `json-read' instead of `setq'ing it.") |
73 | ||
74 | (defvar json-key-type nil | |
75 | "Type to convert JSON keys to. | |
76 | Must be one of `string', `symbol', `keyword', or nil. | |
77 | ||
78 | If nil, `json-read' will guess the type based on the value of | |
79 | `json-object-type': | |
80 | ||
81 | If `json-object-type' is: nil will be interpreted as: | |
82 | `hash-table' `string' | |
83 | `alist' `symbol' | |
84 | `plist' `keyword' | |
85 | ||
86 | Note that values other than `string' might behave strangely for | |
c8de140b | 87 | Sufficiently Weird keys. Consider let-binding this around your call to |
02761f85 MO |
88 | `json-read' instead of `setq'ing it.") |
89 | ||
90 | (defvar json-false :json-false | |
91 | "Value to use when reading JSON `false'. | |
92 | If this has the same value as `json-null', you might not be able to tell | |
c8de140b | 93 | the difference between `false' and `null'. Consider let-binding this |
02761f85 MO |
94 | around your call to `json-read' instead of `setq'ing it.") |
95 | ||
96 | (defvar json-null nil | |
97 | "Value to use when reading JSON `null'. | |
98 | If this has the same value as `json-false', you might not be able to | |
c8de140b | 99 | tell the difference between `false' and `null'. Consider let-binding |
02761f85 MO |
100 | this around your call to `json-read' instead of `setq'ing it.") |
101 | ||
d72e9e92 | 102 | (defvar json-encoding-separator "," |
cccaebd2 | 103 | "Value to use as an element separator when encoding.") |
d72e9e92 RC |
104 | |
105 | (defvar json-encoding-default-indentation " " | |
106 | "The default indentation level for encoding. | |
107 | Used only when `json-encoding-pretty-print' is non-nil.") | |
108 | ||
109 | (defvar json--encoding-current-indentation "\n" | |
110 | "Internally used to keep track of the current indentation level of encoding. | |
111 | Used only when `json-encoding-pretty-print' is non-nil.") | |
112 | ||
113 | (defvar json-encoding-pretty-print nil | |
114 | "If non-nil, then the output of `json-encode' will be pretty-printed.") | |
115 | ||
116 | (defvar json-encoding-lisp-style-closings nil | |
117 | "If non-nil, ] and } closings will be formatted lisp-style, | |
118 | without indentation.") | |
119 | ||
02761f85 MO |
120 | \f |
121 | ||
122 | ;;; Utilities | |
123 | ||
124 | (defun json-join (strings separator) | |
125 | "Join STRINGS with SEPARATOR." | |
126 | (mapconcat 'identity strings separator)) | |
127 | ||
128 | (defun json-alist-p (list) | |
7c1bf12e | 129 | "Non-null if and only if LIST is an alist with simple keys." |
0bc06380 | 130 | (while (consp list) |
7c1bf12e SS |
131 | (setq list (if (and (consp (car list)) |
132 | (atom (caar list))) | |
0bc06380 TZ |
133 | (cdr list) |
134 | 'not-alist))) | |
135 | (null list)) | |
02761f85 MO |
136 | |
137 | (defun json-plist-p (list) | |
398d17da | 138 | "Non-null if and only if LIST is a plist." |
0bc06380 TZ |
139 | (while (consp list) |
140 | (setq list (if (and (keywordp (car list)) | |
141 | (consp (cdr list))) | |
142 | (cddr list) | |
143 | 'not-plist))) | |
144 | (null list)) | |
02761f85 | 145 | |
d72e9e92 RC |
146 | (defmacro json--with-indentation (body) |
147 | `(let ((json--encoding-current-indentation | |
148 | (if json-encoding-pretty-print | |
149 | (concat json--encoding-current-indentation | |
150 | json-encoding-default-indentation) | |
151 | ""))) | |
152 | ,body)) | |
153 | ||
02761f85 MO |
154 | ;; Reader utilities |
155 | ||
156 | (defsubst json-advance (&optional n) | |
157 | "Skip past the following N characters." | |
ac611f4f | 158 | (forward-char n)) |
02761f85 MO |
159 | |
160 | (defsubst json-peek () | |
161 | "Return the character at point." | |
162 | (let ((char (char-after (point)))) | |
163 | (or char :json-eof))) | |
164 | ||
165 | (defsubst json-pop () | |
166 | "Advance past the character at point, returning it." | |
167 | (let ((char (json-peek))) | |
168 | (if (eq char :json-eof) | |
169 | (signal 'end-of-file nil) | |
170 | (json-advance) | |
171 | char))) | |
172 | ||
173 | (defun json-skip-whitespace () | |
174 | "Skip past the whitespace at point." | |
b111d5d0 | 175 | (skip-chars-forward "\t\r\n\f\b ")) |
02761f85 MO |
176 | |
177 | \f | |
178 | ||
179 | ;; Error conditions | |
180 | ||
54bd972f SM |
181 | (define-error 'json-error "Unknown JSON error") |
182 | (define-error 'json-readtable-error "JSON readtable error" 'json-error) | |
183 | (define-error 'json-unknown-keyword "Unrecognized keyword" 'json-error) | |
184 | (define-error 'json-number-format "Invalid number format" 'json-error) | |
185 | (define-error 'json-string-escape "Bad Unicode escape" 'json-error) | |
186 | (define-error 'json-string-format "Bad string format" 'json-error) | |
187 | (define-error 'json-key-format "Bad JSON object key" 'json-error) | |
188 | (define-error 'json-object-format "Bad JSON object" 'json-error) | |
02761f85 MO |
189 | |
190 | \f | |
191 | ||
192 | ;;; Keywords | |
193 | ||
194 | (defvar json-keywords '("true" "false" "null") | |
195 | "List of JSON keywords.") | |
196 | ||
197 | ;; Keyword parsing | |
198 | ||
199 | (defun json-read-keyword (keyword) | |
200 | "Read a JSON keyword at point. | |
201 | KEYWORD is the keyword expected." | |
202 | (unless (member keyword json-keywords) | |
203 | (signal 'json-unknown-keyword (list keyword))) | |
204 | (mapc (lambda (char) | |
205 | (unless (char-equal char (json-peek)) | |
206 | (signal 'json-unknown-keyword | |
207 | (list (save-excursion | |
208 | (backward-word 1) | |
f62e3e0a | 209 | (thing-at-point 'word))))) |
02761f85 MO |
210 | (json-advance)) |
211 | keyword) | |
212 | (unless (looking-at "\\(\\s-\\|[],}]\\|$\\)") | |
213 | (signal 'json-unknown-keyword | |
214 | (list (save-excursion | |
215 | (backward-word 1) | |
f62e3e0a | 216 | (thing-at-point 'word))))) |
02761f85 MO |
217 | (cond ((string-equal keyword "true") t) |
218 | ((string-equal keyword "false") json-false) | |
219 | ((string-equal keyword "null") json-null))) | |
220 | ||
221 | ;; Keyword encoding | |
222 | ||
223 | (defun json-encode-keyword (keyword) | |
224 | "Encode KEYWORD as a JSON value." | |
225 | (cond ((eq keyword t) "true") | |
226 | ((eq keyword json-false) "false") | |
227 | ((eq keyword json-null) "null"))) | |
228 | ||
229 | ;;; Numbers | |
230 | ||
231 | ;; Number parsing | |
232 | ||
7712319d CY |
233 | (defun json-read-number (&optional sign) |
234 | "Read the JSON number following point. | |
c8de140b | 235 | The optional SIGN argument is for internal use. |
7712319d | 236 | |
02761f85 MO |
237 | N.B.: Only numbers which can fit in Emacs Lisp's native number |
238 | representation will be parsed correctly." | |
7712319d CY |
239 | ;; If SIGN is non-nil, the number is explicitly signed. |
240 | (let ((number-regexp | |
241 | "\\([0-9]+\\)?\\(\\.[0-9]+\\)?\\([Ee][+-]?[0-9]+\\)?")) | |
242 | (cond ((and (null sign) (char-equal (json-peek) ?-)) | |
243 | (json-advance) | |
244 | (- (json-read-number t))) | |
245 | ((and (null sign) (char-equal (json-peek) ?+)) | |
246 | (json-advance) | |
247 | (json-read-number t)) | |
248 | ((and (looking-at number-regexp) | |
249 | (or (match-beginning 1) | |
250 | (match-beginning 2))) | |
02761f85 MO |
251 | (goto-char (match-end 0)) |
252 | (string-to-number (match-string 0))) | |
7712319d | 253 | (t (signal 'json-number-format (list (point))))))) |
02761f85 MO |
254 | |
255 | ;; Number encoding | |
256 | ||
257 | (defun json-encode-number (number) | |
258 | "Return a JSON representation of NUMBER." | |
259 | (format "%s" number)) | |
260 | ||
261 | ;;; Strings | |
262 | ||
263 | (defvar json-special-chars | |
264 | '((?\" . ?\") | |
265 | (?\\ . ?\\) | |
266 | (?/ . ?/) | |
267 | (?b . ?\b) | |
268 | (?f . ?\f) | |
269 | (?n . ?\n) | |
270 | (?r . ?\r) | |
271 | (?t . ?\t)) | |
272 | "Characters which are escaped in JSON, with their elisp counterparts.") | |
273 | ||
274 | ;; String parsing | |
275 | ||
276 | (defun json-read-escaped-char () | |
277 | "Read the JSON string escaped character at point." | |
278 | ;; Skip over the '\' | |
279 | (json-advance) | |
280 | (let* ((char (json-pop)) | |
281 | (special (assq char json-special-chars))) | |
282 | (cond | |
283 | (special (cdr special)) | |
284 | ((not (eq char ?u)) char) | |
285 | ((looking-at "[0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f]") | |
286 | (let ((hex (match-string 0))) | |
287 | (json-advance 4) | |
288 | (json-decode-char0 'ucs (string-to-number hex 16)))) | |
289 | (t | |
290 | (signal 'json-string-escape (list (point))))))) | |
291 | ||
292 | (defun json-read-string () | |
293 | "Read the JSON string at point." | |
294 | (unless (char-equal (json-peek) ?\") | |
295 | (signal 'json-string-format (list "doesn't start with '\"'!"))) | |
296 | ;; Skip over the '"' | |
297 | (json-advance) | |
298 | (let ((characters '()) | |
299 | (char (json-peek))) | |
300 | (while (not (char-equal char ?\")) | |
301 | (push (if (char-equal char ?\\) | |
302 | (json-read-escaped-char) | |
303 | (json-pop)) | |
304 | characters) | |
305 | (setq char (json-peek))) | |
306 | ;; Skip over the '"' | |
307 | (json-advance) | |
308 | (if characters | |
309 | (apply 'string (nreverse characters)) | |
310 | ""))) | |
311 | ||
312 | ;; String encoding | |
313 | ||
314 | (defun json-encode-char (char) | |
315 | "Encode CHAR as a JSON string." | |
316 | (setq char (json-encode-char0 char 'ucs)) | |
317 | (let ((control-char (car (rassoc char json-special-chars)))) | |
318 | (cond | |
9cad61d6 | 319 | ;; Special JSON character (\n, \r, etc.). |
02761f85 MO |
320 | (control-char |
321 | (format "\\%c" control-char)) | |
9cad61d6 | 322 | ;; ASCIIish printable character. |
e28e67b3 | 323 | ((and (> char 31) (< char 127)) |
02761f85 | 324 | (format "%c" char)) |
9cad61d6 | 325 | ;; Fallback: UCS code point in \uNNNN form. |
02761f85 MO |
326 | (t |
327 | (format "\\u%04x" char))))) | |
328 | ||
329 | (defun json-encode-string (string) | |
330 | "Return a JSON representation of STRING." | |
331 | (format "\"%s\"" (mapconcat 'json-encode-char string ""))) | |
332 | ||
94e0e559 EC |
333 | (defun json-encode-key (object) |
334 | "Return a JSON representation of OBJECT. | |
335 | If the resulting JSON object isn't a valid JSON object key, | |
336 | this signals `json-key-format'." | |
337 | (let ((encoded (json-encode object))) | |
338 | (unless (stringp (json-read-from-string encoded)) | |
339 | (signal 'json-key-format (list object))) | |
340 | encoded)) | |
341 | ||
02761f85 MO |
342 | ;;; JSON Objects |
343 | ||
344 | (defun json-new-object () | |
345 | "Create a new Elisp object corresponding to a JSON object. | |
346 | Please see the documentation of `json-object-type'." | |
347 | (cond ((eq json-object-type 'hash-table) | |
348 | (make-hash-table :test 'equal)) | |
349 | (t | |
350 | (list)))) | |
351 | ||
352 | (defun json-add-to-object (object key value) | |
353 | "Add a new KEY -> VALUE association to OBJECT. | |
354 | Returns the updated object, which you should save, e.g.: | |
355 | (setq obj (json-add-to-object obj \"foo\" \"bar\")) | |
356 | Please see the documentation of `json-object-type' and `json-key-type'." | |
357 | (let ((json-key-type | |
358 | (if (eq json-key-type nil) | |
359 | (cdr (assq json-object-type '((hash-table . string) | |
360 | (alist . symbol) | |
361 | (plist . keyword)))) | |
362 | json-key-type))) | |
363 | (setq key | |
364 | (cond ((eq json-key-type 'string) | |
365 | key) | |
366 | ((eq json-key-type 'symbol) | |
367 | (intern key)) | |
368 | ((eq json-key-type 'keyword) | |
369 | (intern (concat ":" key))))) | |
370 | (cond ((eq json-object-type 'hash-table) | |
371 | (puthash key value object) | |
372 | object) | |
373 | ((eq json-object-type 'alist) | |
374 | (cons (cons key value) object)) | |
375 | ((eq json-object-type 'plist) | |
376 | (cons key (cons value object)))))) | |
377 | ||
378 | ;; JSON object parsing | |
379 | ||
380 | (defun json-read-object () | |
381 | "Read the JSON object at point." | |
382 | ;; Skip over the "{" | |
383 | (json-advance) | |
384 | (json-skip-whitespace) | |
385 | ;; read key/value pairs until "}" | |
386 | (let ((elements (json-new-object)) | |
387 | key value) | |
388 | (while (not (char-equal (json-peek) ?})) | |
389 | (json-skip-whitespace) | |
390 | (setq key (json-read-string)) | |
391 | (json-skip-whitespace) | |
392 | (if (char-equal (json-peek) ?:) | |
393 | (json-advance) | |
394 | (signal 'json-object-format (list ":" (json-peek)))) | |
395 | (setq value (json-read)) | |
396 | (setq elements (json-add-to-object elements key value)) | |
397 | (json-skip-whitespace) | |
398 | (unless (char-equal (json-peek) ?}) | |
399 | (if (char-equal (json-peek) ?,) | |
400 | (json-advance) | |
401 | (signal 'json-object-format (list "," (json-peek)))))) | |
402 | ;; Skip over the "}" | |
403 | (json-advance) | |
404 | elements)) | |
405 | ||
406 | ;; Hash table encoding | |
407 | ||
408 | (defun json-encode-hash-table (hash-table) | |
409 | "Return a JSON representation of HASH-TABLE." | |
d72e9e92 | 410 | (format "{%s%s}" |
02761f85 MO |
411 | (json-join |
412 | (let (r) | |
d72e9e92 RC |
413 | (json--with-indentation |
414 | (maphash | |
415 | (lambda (k v) | |
416 | (push (format | |
417 | (if json-encoding-pretty-print | |
418 | "%s%s: %s" | |
419 | "%s%s:%s") | |
420 | json--encoding-current-indentation | |
421 | (json-encode-key k) | |
422 | (json-encode v)) | |
423 | r)) | |
424 | hash-table)) | |
02761f85 | 425 | r) |
d72e9e92 RC |
426 | json-encoding-separator) |
427 | (if (or (not json-encoding-pretty-print) | |
428 | json-encoding-lisp-style-closings) | |
429 | "" | |
430 | json--encoding-current-indentation))) | |
02761f85 MO |
431 | |
432 | ;; List encoding (including alists and plists) | |
433 | ||
434 | (defun json-encode-alist (alist) | |
435 | "Return a JSON representation of ALIST." | |
d72e9e92 RC |
436 | (format "{%s%s}" |
437 | (json-join | |
438 | (json--with-indentation | |
439 | (mapcar (lambda (cons) | |
440 | (format (if json-encoding-pretty-print | |
441 | "%s%s: %s" | |
442 | "%s%s:%s") | |
443 | json--encoding-current-indentation | |
444 | (json-encode-key (car cons)) | |
445 | (json-encode (cdr cons)))) | |
446 | alist)) | |
447 | json-encoding-separator) | |
448 | (if (or (not json-encoding-pretty-print) | |
449 | json-encoding-lisp-style-closings) | |
450 | "" | |
451 | json--encoding-current-indentation))) | |
02761f85 MO |
452 | |
453 | (defun json-encode-plist (plist) | |
454 | "Return a JSON representation of PLIST." | |
455 | (let (result) | |
d72e9e92 RC |
456 | (json--with-indentation |
457 | (while plist | |
458 | (push (concat | |
459 | json--encoding-current-indentation | |
460 | (json-encode-key (car plist)) | |
461 | (if json-encoding-pretty-print | |
462 | ": " | |
463 | ":") | |
464 | (json-encode (cadr plist))) | |
465 | result) | |
466 | (setq plist (cddr plist)))) | |
467 | (concat "{" | |
468 | (json-join (nreverse result) json-encoding-separator) | |
469 | (if (and json-encoding-pretty-print | |
470 | (not json-encoding-lisp-style-closings)) | |
471 | json--encoding-current-indentation | |
472 | "") | |
473 | "}"))) | |
02761f85 MO |
474 | |
475 | (defun json-encode-list (list) | |
476 | "Return a JSON representation of LIST. | |
477 | Tries to DWIM: simple lists become JSON arrays, while alists and plists | |
478 | become JSON objects." | |
479 | (cond ((null list) "null") | |
480 | ((json-alist-p list) (json-encode-alist list)) | |
481 | ((json-plist-p list) (json-encode-plist list)) | |
482 | ((listp list) (json-encode-array list)) | |
483 | (t | |
484 | (signal 'json-error (list list))))) | |
485 | ||
486 | ;;; Arrays | |
487 | ||
488 | ;; Array parsing | |
489 | ||
490 | (defun json-read-array () | |
491 | "Read the JSON array at point." | |
492 | ;; Skip over the "[" | |
493 | (json-advance) | |
494 | (json-skip-whitespace) | |
495 | ;; read values until "]" | |
496 | (let (elements) | |
497 | (while (not (char-equal (json-peek) ?\])) | |
498 | (push (json-read) elements) | |
499 | (json-skip-whitespace) | |
500 | (unless (char-equal (json-peek) ?\]) | |
501 | (if (char-equal (json-peek) ?,) | |
502 | (json-advance) | |
503 | (signal 'json-error (list 'bleah))))) | |
504 | ;; Skip over the "]" | |
505 | (json-advance) | |
506 | (apply json-array-type (nreverse elements)))) | |
507 | ||
508 | ;; Array encoding | |
509 | ||
510 | (defun json-encode-array (array) | |
511 | "Return a JSON representation of ARRAY." | |
d72e9e92 RC |
512 | (if (and json-encoding-pretty-print |
513 | (> (length array) 0)) | |
514 | (concat | |
515 | (json--with-indentation | |
516 | (concat (format "[%s" json--encoding-current-indentation) | |
517 | (json-join (mapcar 'json-encode array) | |
518 | (format "%s%s" | |
519 | json-encoding-separator | |
520 | json--encoding-current-indentation)))) | |
521 | (format "%s]" | |
522 | (if json-encoding-lisp-style-closings | |
523 | "" | |
524 | json--encoding-current-indentation))) | |
525 | (concat "[" | |
526 | (mapconcat 'json-encode array json-encoding-separator) | |
527 | "]"))) | |
02761f85 MO |
528 | |
529 | \f | |
530 | ||
531 | ;;; JSON reader. | |
532 | ||
533 | (defvar json-readtable | |
534 | (let ((table | |
535 | '((?t json-read-keyword "true") | |
536 | (?f json-read-keyword "false") | |
537 | (?n json-read-keyword "null") | |
538 | (?{ json-read-object) | |
539 | (?\[ json-read-array) | |
540 | (?\" json-read-string)))) | |
541 | (mapc (lambda (char) | |
542 | (push (list char 'json-read-number) table)) | |
7712319d | 543 | '(?- ?+ ?. ?0 ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9)) |
02761f85 MO |
544 | table) |
545 | "Readtable for JSON reader.") | |
546 | ||
547 | (defun json-read () | |
548 | "Parse and return the JSON object following point. | |
549 | Advances point just past JSON object." | |
550 | (json-skip-whitespace) | |
551 | (let ((char (json-peek))) | |
552 | (if (not (eq char :json-eof)) | |
553 | (let ((record (cdr (assq char json-readtable)))) | |
554 | (if (functionp (car record)) | |
555 | (apply (car record) (cdr record)) | |
556 | (signal 'json-readtable-error record))) | |
557 | (signal 'end-of-file nil)))) | |
558 | ||
559 | ;; Syntactic sugar for the reader | |
560 | ||
561 | (defun json-read-from-string (string) | |
562 | "Read the JSON object contained in STRING and return it." | |
563 | (with-temp-buffer | |
564 | (insert string) | |
565 | (goto-char (point-min)) | |
566 | (json-read))) | |
567 | ||
568 | (defun json-read-file (file) | |
569 | "Read the first JSON object contained in FILE and return it." | |
570 | (with-temp-buffer | |
571 | (insert-file-contents file) | |
572 | (goto-char (point-min)) | |
573 | (json-read))) | |
574 | ||
575 | \f | |
576 | ||
577 | ;;; JSON encoder | |
578 | ||
579 | (defun json-encode (object) | |
580 | "Return a JSON representation of OBJECT as a string." | |
581 | (cond ((memq object (list t json-null json-false)) | |
582 | (json-encode-keyword object)) | |
583 | ((stringp object) (json-encode-string object)) | |
584 | ((keywordp object) (json-encode-string | |
585 | (substring (symbol-name object) 1))) | |
586 | ((symbolp object) (json-encode-string | |
587 | (symbol-name object))) | |
588 | ((numberp object) (json-encode-number object)) | |
589 | ((arrayp object) (json-encode-array object)) | |
590 | ((hash-table-p object) (json-encode-hash-table object)) | |
591 | ((listp object) (json-encode-list object)) | |
592 | (t (signal 'json-error (list object))))) | |
593 | ||
d72e9e92 RC |
594 | ;; Pretty printing |
595 | ||
596 | (defun json-pretty-print-buffer () | |
597 | "Pretty-print current buffer." | |
598 | (interactive) | |
599 | (json-pretty-print (point-min) (point-max))) | |
600 | ||
601 | (defun json-pretty-print (begin end) | |
602 | "Pretty-print selected region." | |
603 | (interactive "r") | |
604 | (atomic-change-group | |
605 | (let ((json-encoding-pretty-print t) | |
606 | (txt (delete-and-extract-region begin end))) | |
607 | (insert (json-encode (json-read-from-string txt)))))) | |
608 | ||
02761f85 MO |
609 | (provide 'json) |
610 | ||
611 | ;;; json.el ends here |