anchor.diff:           (clear scr)
            ;; display the human-readable version of a wide char by using the utf-8 %waddch interface.
            ;; adding both attributes and colors works this way.
  -         (add-wide-char scr ch :attributes (list :underline :bold) :color-pair (list :red :yellow) :y 0 :x 0)
  +         (add-wide-char scr ch             :attributes (list :underline) :color-pair (list :yellow :red) :y 0 :x 0)
  +         (add-wide-char scr (code-char ch) :attributes (list :bold)      :color-pair (list :yellow :red) :y 0 :x 2)
            ;; extract the wide char added by the utf-8 %waddch interface.
            (let ((ch2 (extract-wide-char scr :y 0 :x 0)))
              ;; display the lisp-readable version of the extracted wide char
              (move scr 1 0)
              (prin1 (.simple-char ch2) scr)
              ;; print the slots of the extracted complex wide char
  -           (add-wide-char scr ch2 :y 2 :x 0)
              (princ (.attributes ch2) scr)
  -           (princ (.color-pair ch2) scr)))))
  +           (princ (.color-pair ch2) scr)
  +           (add-wide-char scr ch2 :y 3 :x 0) ))))
   
   ;; take a function given as symbol name and display its docstring. press q to exit.
   ;; Example: (a:t04 'cdr)
  
positive.code:   (unwind-protect
         (let ((scr (make-instance 'screen :enable-colors t)))
  
           ;; the text will be red on yellow. this doesnt set the overall background, just the text background.
           (setf (.color-pair scr) '(:red :yellow))
  
           (clear scr)
           (move scr 0 0)
           (add-string scr "hello there!")
           (move scr 5 5)
           (add-string scr "dear john!")
           (move-by scr 5 5)
           (add-string scr "call me maybe!")
           (refresh scr)
  
           ;; wait for keypress, works only in blocking mode, which is the default.
           (get-char scr)
  
           ;; set a background. green dots on white background.
           (setf (.background scr) (make-instance 'complex-char :simple-char #\. :color-pair '(:green :white)))
  
           (refresh scr)
  
           ;; wait for the next keypress, then end.
  
negative.code:            (move-by win 0 1)))
          (#\newline ; RET key, C-j, C-m
             (when (> n 0) ; only print when the line is not empty.
               (let* ((strin (extract-wide-string win :n n :y 0 :x 0)) 
                      (strout (eval (read-from-string strin))))
                 (princ strin)
                 (terpri)
                 (add-string wout (format nil "=> ~A~%~%" strout)))
               (setf n 0)
               (clear win) ; empty the input line after evaluation.
               (refresh wout)))
  