anchor.diff:  @export
   (define-condition lookuptable-does-not-contain-item (error)
     ((%index
  -    :initarg index
  +    :initarg :index
       :type index
       :reader read-index)))
   
  
positive.code:   ((%replacer
      :type vector-replacer
      :initarg :replacer
      :reader read-replacer)
     (%mask-length
      :type (unsigned-byte 8)
      :initarg :mask-length
      :initform 32
      :reader read-mask-length)))
  
  
  @export
  
negative.code:     :reader read-container
      :initarg :container)
     (%mask
      :type (unsigned-byte 64)
      :initarg :mask
      :reader read-mask))
    (:documentation "Lookuptable that can hold up to 32 elements, under 32 indexes (from 0 to 31)."))
  