anchor.diff:  
   (defun encode-alist (object &optional (stream *standard-output*))
     (loop initially (write-char #\{ stream)
  -     with printed = nil
  -     for (key . value) in object
  -     do (if printed
  -            (write-char #\, stream)
  -            (setf printed t))
  -       (encode-symbol/value key value stream)
  -     finally (write-char #\} stream)
  -       (return object)))
  +        with printed = nil
  +        for (key . value) in object
  +        do (if printed
  +               (write-char #\, stream)
  +               (setf printed t))
  +           (encode-symbol/value key value stream)
  +        finally (write-char #\} stream)
  +                (return object)))
   
   (defun encode-plist (object &optional (stream *standard-output*))
     (loop initially (write-char #\{ stream)
  -     with printed = nil
  -     for (key value . rest) on object by #'cddr
  -     do (if printed
  -            (write-char #\, stream)
  -            (setf printed t))
  -       (encode-symbol/value key value stream)
  -     finally (write-char #\} stream)
  -       (return object)))
  +        with printed = nil
  +        for (key value . rest) on object by #'cddr
  +        do (if printed
  +               (write-char #\, stream)
  +               (setf printed t))
  +           (encode-symbol/value key value stream)
  +        finally (write-char #\} stream)
  +                (return object)))
   
   (defmethod encode ((object (eql 'true)) &optional (stream *standard-output*))
     (write-string "true" stream)
  
positive.code:   (write-char #\[ stream)
    (let (printed)
      (loop
         for value across object
         do
         (when printed
           (write-char #\, stream))
         (setf printed t)
         (encode value stream)))
    (write-char #\] stream)
    object)
  
  
negative.code: (defun encode-object-elements (&rest elements)
    "Encode plist ELEMENTS as object elements."
    (loop for (key value) on elements by #'cddr
          do (encode-object-element key value)))
  
  (defmacro with-object-element ((key) &body body)
    "Open a new encoding context to encode a JSON object element.  KEY
  