[plt-scheme] move-circle problem

arnuld fraser wrote:

> (define (translate-circle a-color-circle delta)
>   (draw-circle (make-posn (+ delta (posn-x (color-circle-center 
> a-color-circle)))
>                           (posn-y (color-circle-center a-color-circle)))
>                (color-circle-radius a-color-circle)
>                (color-circle-color a-color-circle)))

Here is the problem. The function translate-circle has the contract

  translate-circle : circle number -> circle

so you have to change a single function call.

-- 
Jens Axel Søgaard