anchor.diff:     (background
       :initarg       :background
       :initform      nil
  -    :type          complex-char
  +    :type          (or null complex-char)
       :documentation "A complex char to form the background of a window.")
   
      (attributes
       :initarg       :attributes
       :initform      nil
  -    :type          cons
  +    :type          (or null cons)
       :documentation "A list of attribute keywords.")
   
      (color-pair
       :initarg       :color-pair
       :initform      nil
  -    :type          cons
  +    :type          (or null cons)
       :documentation "A two element list of keywords denoting the foregreound and background color of text displayed in the window.")
   
      ;; TODO: Doesnt survive a "clear" command yet.
  
positive.code:   ((simple-char
      :initarg :simple-char
      :initform nil
      :accessor .simple-char
      :documentation "Lisp primitive character type, like #\a.")
  
     (attributes
      :initarg :attributes
      :initform '()
      :accessor .attributes
      :documentation "List of keywords denoting attributes.")
  
     (color-pair
      :initarg :color-pair
      :initform '(:white :black)
      :accessor .color-pair
      :documentation "Two element list of keywords denoting a foreground and background color of the char."))
  
  
negative.code:    (width
      :initarg       :width
      :initform      0
      :type          integer
      :documentation "The width (second, horizontal, x dimension) of the window.")
  
     (height
      :initarg       :height
      :initform      0
      :type          integer
      :documentation "The height (first, vertical, y dimension) of the window.")
  
     ;; has to be a 2el-list so we can use 1 arg with setf.
  