[plt-scheme] Re: Permutation correct way to do it ?

On Apr 13, 2008, at 12:30 PM, Veer wrote:
> ;;process-circle : (posn number symbol -> X)  circle -> X
> ;;to apply function f on the fields of a-circle
> (define (process-circle f a-circle)
>   (f (circle-center a-circle) (circle-radius a-circle) (circle- 
> color a-circle)))


You didn't finish the design recipe here. Before you proceed,
you must demonstrate that that you can define

  draw-circle in terms of process-circle
  clear-circle in terms of process-circle

(and these definitions should be really short). Do so for all
abstractions.

;; ---

You can also abstract over the list-processing functions
draw-losh, clear-losh but of course, the appropriate function
already exists; see table on page 313.

-- Matthias