   :safe #'stringp)
 (make-variable-buffer-local 'clang-format-style)
 
+(defun clang-format--extract (xml-node)
+  "Extract replacements and cursor information from XML-NODE."
+  (unless (and (listp xml-node) (eq (xml-node-name xml-node) 'replacements))
+    (error "Expected <replacements> node"))
+  (let ((nodes (xml-node-children xml-node))
+        replacements
+        cursor)
+    (dolist (node nodes)
+      (when (listp node)
+        (let* ((children (xml-node-children node))
+               (text (car children)))
+          (cl-case (xml-node-name node)
+            ('replacement
+             (let* ((offset (xml-get-attribute-or-nil node 'offset))
+                    (length (xml-get-attribute-or-nil node 'length)))
+               (when (or (null offset) (null length))
+                 (error "<replacement> node does not have offset and length attributes"))
+               (when (cdr children)
+                 (error "More than one child node in <replacement> node"))
+
+               (setq offset (1+ (string-to-number offset)))
+               (setq length (string-to-number length))
+               (push (list offset length text) replacements)))
+            ('cursor
+             (setq cursor (1+ (string-to-number text))))))))
+
+    ;; Sort by decreasing offset, length.
+    (setq replacements (sort (delq nil replacements)
+                             (lambda (a b)
+                               (or (> (car a) (car b))
+                                   (and (= (car a) (car b))
+                                        (> (cadr a) (cadr b)))))))
+
+    (cons replacements cursor)))
+
+(defun clang-format--replace (offset length &optional text)
+  (goto-char offset)
+  (delete-char length)
+  (when text
+    (insert text)))
+
 ;;;###autoload
 (defun clang-format-region (start end &optional style)
   "Use clang-format to format the code between START and END according to STYLE.

  (unless style
    (setq style clang-format-style))

  (let* ((temp-file (make-temp-file "clang-format"))
         (keep-stderr (list t temp-file))
         (window-starts
          (mapcar (lambda (w) (list w (window-start w)))
                  (get-buffer-window-list)))
         (status)
         (stderr)
         (json))

    (unwind-protect
        (setq status
              (call-process-region
               (point-min) (point-max) clang-format-executable
               'delete keep-stderr nil

               "-assume-filename" (or (buffer-file-name) "")
               "-style" style
               "-offset" (number-to-string (1- start))
               "-length" (number-to-string (- end start))
               "-cursor" (number-to-string (1- (point))))
              stderr
              (with-temp-buffer
                (insert-file-contents temp-file)
                (when (> (point-max) (point-min))
                  (insert ": "))
                (buffer-substring-no-properties
                 (point-min) (line-end-position))))
      (delete-file temp-file))

    (cond
     ((stringp status)
      (error "(clang-format killed by signal %s%s)" status stderr))
     ((not (equal 0 status))
      (error "(clang-format failed with code %d%s)" status stderr))
     (t (message "(clang-format succeeded%s)" stderr)))

    (goto-char (point-min))
    (setq json (json-read-from-string
                (buffer-substring-no-properties
                 (point-min) (line-end-position))))

    (delete-region (point-min) (line-beginning-position 2))
    (mapc (lambda (w) (apply #'set-window-start w))
          window-starts)
    (goto-char (1+ (cdr (assoc 'Cursor json))))))

;;;###autoload
(defun clang-format-buffer (&optional style)


;;; Code:

(require 'cl-lib)
(require 'xml)

(defgroup clang-format nil
  "Format code using clang-format."
