anchor.diff:               (prog1 stream
                  (setf (stream-index stream) index))
                (setf (stream-%next stream)
  -                   (future-value (stream-next stream)))))))
  +                   (parallel:future-value* (stream-next stream)))))))
   
   (defun parallel:tail-prefetch (stream)
     (when (and (stream-p stream)
  
positive.code:                            value (values-list values))))
                  (t
                   (return (values)))))
        (future-value future))))
  
  (defmacro parallel:bind ((&rest bindings)
                           &body body)
  
negative.code:               (lambda ,(mapcar #'first bindings)
                  ,@body)))))
  
  (defconstant +chunk-size+ 1024)
  
  (defstruct (parallel:stream
              (:constructor %make-stream))
  