anchor.diff:  ;; - Why is (EQ (MAKE-TEXT-STYLE NIL NIL 10) (MAKE-TEXT-STYLE NIL NIL 10.0005)) = T?
   ;;   Does it matter?
   ;; - Don't we want a weak hash-table for *TEXT-STYLE-HASH-TABLE*
  -;; - we need more macro hygiene in WITH-TEXT-STYLE
  -;;
  -;; --GB 2002-02-26
  -
  -;;; Media
  -
  -;; - MEDIUM-DRAW-POINTS*, MEDIUM-DRAW-LINES*, MEDIUM-DRAW-RECTANGLES*
  -;; - MEDIUM-DRAW-RECTANGLES*: POSITION-SEQ argument can be a
  -;;   vector. Use MAP-REPEATED-SEQUENCE.
   ;;
   ;; --GB 2002-02-26
   
  
positive.code:       s1))
  
  (defun parse-text-style (style)
    (if (text-style-p style)
        style
      (let ((family nil)
  	  (face nil)
  	  (size nil))
        (loop for item in style
  	    do (cond
  		((member item '(:fix :serif :sans-serif))
  		 (setq family item))
  		((or (member item '(:roman :bold :italic))
  		     (consp item))
  		 (setq face item))
  		((or (member item '(:tiny :very-small :small :normal
  				    :large :very-large :huge))
  		     (numberp item))
  		 (setq size item))))
        (make-text-style family face size))))
  
  (defmacro with-text-style ((medium text-style) &body body)
    (when (eq medium t)
      (setq medium '*standard-output*))
    (check-type medium symbol)
    `(flet ((continuation (,medium)
              (declare (ignorable ,medium))
  	    ,@body))
       (declare (dynamic-extent #'continuation))
       (invoke-with-text-style ,medium #'continuation
                               (parse-text-style ,text-style))))
  
  (defmethod invoke-with-text-style ((sheet sheet) continuation text-style)
    (let ((medium (sheet-medium sheet))) ; FIXME: WITH-SHEET-MEDIUM
  
negative.code: ;;; Fall-through Methods For Multiple Objects Drawing Functions
  
  (defmethod medium-draw-points* ((medium basic-medium) coord-seq)
    (let ((tr (invert-transformation (medium-transformation medium))))
      (with-transformed-positions (tr coord-seq)
        (map-repeated-sequence nil 2
                               (lambda (x y)
                                 (medium-draw-point* medium x y))
                               coord-seq))))
  
  (defmethod medium-draw-lines* ((medium basic-medium) position-seq)
    (let ((tr (invert-transformation (medium-transformation medium))))
      (with-transformed-positions (tr position-seq)
        (map-repeated-sequence nil 4
                               (lambda (x1 y1 x2 y2)
                                 (medium-draw-line* medium x1 y1 x2 y2))
                               position-seq))))
  
  (defmethod medium-draw-rectangles* ((medium basic-medium) coord-seq filled)
    (let ((tr (invert-transformation (medium-transformation medium))))
      (with-transformed-positions (tr coord-seq)
        (map-repeated-sequence nil 4
                               (lambda (x1 y1 x2 y2)
                                 (medium-draw-rectangle* medium
                                                         x1 y1 x2 y2
                                                         filled))
                               coord-seq))))
  
  
  