X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/e427b55370b28f55e285ce0ee4328246eb7522ea..2958e5237c6ee57378f1b47217aafd0b21ec86ab:/lisp/json.el

diff --git a/lisp/json.el b/lisp/json.el
index 98974e67b7..eaf8596a6d 100644
--- a/lisp/json.el
+++ b/lisp/json.el
@@ -52,13 +52,6 @@
 
 ;;; Code:
 
-
-;; Compatibility code
-
-(defalias 'json-encode-char0 'encode-char)
-(defalias 'json-decode-char0 'decode-char)
-
-
 ;; Parameters
 
 (defvar json-object-type 'alist
@@ -265,7 +258,6 @@ representation will be parsed correctly."
 (defvar json-special-chars
   '((?\" . ?\")
     (?\\ . ?\\)
-    (?/ . ?/)
     (?b . ?\b)
     (?f . ?\f)
     (?n . ?\n)
@@ -287,7 +279,7 @@ representation will be parsed correctly."
      ((looking-at "[0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f]")
       (let ((hex (match-string 0)))
         (json-advance 4)
-        (json-decode-char0 'ucs (string-to-number hex 16))))
+        (string-to-number hex 16)))
      (t
       (signal 'json-string-escape (list (point)))))))
 
@@ -313,24 +305,29 @@ representation will be parsed correctly."
 
 ;; String encoding
 
-(defun json-encode-char (char)
-  "Encode CHAR as a JSON string."
-  (setq char (json-encode-char0 char 'ucs))
-  (let ((control-char (car (rassoc char json-special-chars))))
-    (cond
-     ;; Special JSON character (\n, \r, etc.).
-     (control-char
-      (format "\\%c" control-char))
-     ;; ASCIIish printable character.
-     ((and (> char 31) (< char 127))
-      (format "%c" char))
-     ;; Fallback: UCS code point in \uNNNN form.
-     (t
-      (format "\\u%04x" char)))))
-
 (defun json-encode-string (string)
   "Return a JSON representation of STRING."
-  (format "\"%s\"" (mapconcat 'json-encode-char string "")))
+  ;; Reimplement the meat of `replace-regexp-in-string', for
+  ;; performance (bug#20154).
+  (let ((l (length string))
+        (start 0)
+        res mb)
+    ;; Only escape quotation mark, backslash and the control
+    ;; characters U+0000 to U+001F (RFC 4627, ECMA-404).
+    (while (setq mb (string-match "[\"\\[:cntrl:]]" string start))
+      (let* ((c (aref string mb))
+             (special (rassq c json-special-chars)))
+        (push (substring string start mb) res)
+        (push (if special
+                  ;; Special JSON character (\n, \r, etc.).
+                  (string ?\\ (car special))
+                ;; Fallback: UCS code point in \uNNNN form.
+                (format "\\u%04x" c))
+              res)
+        (setq start (1+ mb))))
+    (push (substring string start l) res)
+    (push "\"" res)
+    (apply #'concat "\"" (nreverse res))))
 
 (defun json-encode-key (object)
   "Return a JSON representation of OBJECT.