[plt-scheme] Object system

From: Guenther Schmidt (gue.schmidt at web.de)
Date: Sun Dec 21 09:12:12 EST 2003


I don't know the proper terminology, what I'd like to do is this:

I'd like to create a new class derived from one of MrEDs class, overwrite the, for instance, on-subwindow-char method, but still make a call within the new method to the super method.

What is the proper procedure to do this, can it be done?

As an example:

(define my-text-field%
 (class text-field%
   (rename (sup on-subwindow-char))
   (define/override-final on-subwindow-char
     (lambda (x y)
       (display y)
       (sup x y)))
   (super-instantiate ())))

This only works to a certain extent, I have to call "sub" at the very end otherwise it won't work.

Best regards


P.S. I do have Chapter 4 (about class.ss) printed but I'm not sure how to interpret it.

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