anchor.diff:  		 (slot-value ,%state 'current-timestamp) ,%c-t)
   	   (funcall ,return ,%dst ,%src))))))
   
  -(defmacro with-buffer-accessor ((&key (reader (gensym) reader-supplied-p)
  -				      (writer (gensym) writer-supplied-p)
  -				      current)
  +(defmacro with-buffer-accessor ((current
  +				 &key (reader (gensym) reader-supplied-p)
  +				 (writer (gensym) writer-supplied-p))
   				   (buffer start end &key (element-type '*))
   				&body body)
     (alexandria:once-only (buffer start end)
  
positive.code: 	   (type fixnum start1 end1 start2 end2))
    (unless (scsu-state-timestamp-vector state)
      (initialize-timestamp state initial-priority string start1 end1))
    (with-buffer-accessor (:reader pick-char :current src-current)
        (string start1 end1 :element-type character)
      (with-buffer-accessor (:writer put-byte :current dst-current)
  	(bytes start2 end2 :element-type (unsigned-byte 8))
        (loop while (< src-current end1)
  	 do (with-scsu-error-handling
  
negative.code:   	   (type fixnum start1 end1 start2 end2)
    	   (type string string))
    (scsu-trace-output "~2&")
    (with-buffer-accessor (src-current :reader pick-byte)
        (bytes start1 end1 :element-type (unsigned-byte 8))
      (with-buffer-accessor (dst-current :writer put-char)
  	(string start2 end2 :element-type character)
        (loop while (< src-current end1)
  	 do (with-scsu-error-handling
  