| 1 | ;;; json.el --- JavaScript Object Notation parser / generator |
| 2 | |
| 3 | ;; Copyright (C) 2006-2014 Free Software Foundation, Inc. |
| 4 | |
| 5 | ;; Author: Edward O'Connor <ted@oconnor.cx> |
| 6 | ;; Version: 1.4 |
| 7 | ;; Keywords: convenience |
| 8 | |
| 9 | ;; This file is part of GNU Emacs. |
| 10 | |
| 11 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
| 12 | ;; it under the terms of the GNU General Public License as published by |
| 13 | ;; the Free Software Foundation, either version 3 of the License, or |
| 14 | ;; (at your option) any later version. |
| 15 | |
| 16 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 17 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | ;; GNU General Public License for more details. |
| 20 | |
| 21 | ;; You should have received a copy of the GNU General Public License |
| 22 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
| 23 | |
| 24 | ;;; Commentary: |
| 25 | |
| 26 | ;; This 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. |
| 50 | ;; 2011-10-17 - Patch `json-alist-p' and `json-plist-p' to avoid recursion -tzz |
| 51 | ;; 2012-10-25 - Added pretty-printed reformatting -Ryan Crum (ryan@ryancrum.org) |
| 52 | |
| 53 | ;;; Code: |
| 54 | |
| 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. |
| 66 | Must be one of `alist', `plist', or `hash-table'. Consider let-binding |
| 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. |
| 71 | Must be one of `vector' or `list'. Consider let-binding this around |
| 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 |
| 87 | Sufficiently Weird keys. Consider let-binding this around your call to |
| 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 |
| 93 | the difference between `false' and `null'. Consider let-binding this |
| 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 |
| 99 | tell the difference between `false' and `null'. Consider let-binding |
| 100 | this around your call to `json-read' instead of `setq'ing it.") |
| 101 | |
| 102 | (defvar json-encoding-separator "," |
| 103 | "Value to use as an element separator when encoding.") |
| 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 | |
| 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) |
| 129 | "Non-null if and only if LIST is an alist with simple keys." |
| 130 | (while (consp list) |
| 131 | (setq list (if (and (consp (car list)) |
| 132 | (atom (caar list))) |
| 133 | (cdr list) |
| 134 | 'not-alist))) |
| 135 | (null list)) |
| 136 | |
| 137 | (defun json-plist-p (list) |
| 138 | "Non-null if and only if LIST is a plist." |
| 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)) |
| 145 | |
| 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 | |
| 154 | ;; Reader utilities |
| 155 | |
| 156 | (defsubst json-advance (&optional n) |
| 157 | "Skip past the following N characters." |
| 158 | (forward-char n)) |
| 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." |
| 175 | (skip-chars-forward "\t\r\n\f\b ")) |
| 176 | |
| 177 | \f |
| 178 | |
| 179 | ;; Error conditions |
| 180 | |
| 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) |
| 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) |
| 209 | (thing-at-point 'word))))) |
| 210 | (json-advance)) |
| 211 | keyword) |
| 212 | (unless (looking-at "\\(\\s-\\|[],}]\\|$\\)") |
| 213 | (signal 'json-unknown-keyword |
| 214 | (list (save-excursion |
| 215 | (backward-word 1) |
| 216 | (thing-at-point 'word))))) |
| 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 | |
| 233 | (defun json-read-number (&optional sign) |
| 234 | "Read the JSON number following point. |
| 235 | The optional SIGN argument is for internal use. |
| 236 | |
| 237 | N.B.: Only numbers which can fit in Emacs Lisp's native number |
| 238 | representation will be parsed correctly." |
| 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))) |
| 251 | (goto-char (match-end 0)) |
| 252 | (string-to-number (match-string 0))) |
| 253 | (t (signal 'json-number-format (list (point))))))) |
| 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 |
| 319 | ;; Special JSON character (\n, \r, etc.). |
| 320 | (control-char |
| 321 | (format "\\%c" control-char)) |
| 322 | ;; ASCIIish printable character. |
| 323 | ((and (> char 31) (< char 127)) |
| 324 | (format "%c" char)) |
| 325 | ;; Fallback: UCS code point in \uNNNN form. |
| 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 | |
| 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 | |
| 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." |
| 410 | (format "{%s%s}" |
| 411 | (json-join |
| 412 | (let (r) |
| 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)) |
| 425 | r) |
| 426 | json-encoding-separator) |
| 427 | (if (or (not json-encoding-pretty-print) |
| 428 | json-encoding-lisp-style-closings) |
| 429 | "" |
| 430 | json--encoding-current-indentation))) |
| 431 | |
| 432 | ;; List encoding (including alists and plists) |
| 433 | |
| 434 | (defun json-encode-alist (alist) |
| 435 | "Return a JSON representation of ALIST." |
| 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))) |
| 452 | |
| 453 | (defun json-encode-plist (plist) |
| 454 | "Return a JSON representation of PLIST." |
| 455 | (let (result) |
| 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 | "}"))) |
| 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." |
| 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 | "]"))) |
| 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)) |
| 543 | '(?- ?+ ?. ?0 ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9)) |
| 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 | |
| 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 | |
| 609 | (provide 'json) |
| 610 | |
| 611 | ;;; json.el ends here |