scheme question

Hello /prog/, I'm not really much of a programmer but I've been dicking around with Lisp/Scheme lately for fun (DrRacket specifically).  One of the programs in my book goes like this:

;; move-circle : number circle  ->  circle
;; to draw and clear a circle, translate it by delta pixels
(define-struct circle (center radius color))

(define (move-circle delta a-circle)
  (cond
    [(draw-and-clear-circle a-circle) (translate-circle a-circle delta)]
    [else a-circle]))

draw-and-clear-circle draws and clears a circle, obviously, and translate-circle simply modifies the given "circle" structure such that its position is shifted by "delta" pixels.  So if I wanted to make a circle move across the screen I could run something like

(draw-a-circle (move-circle 10 (move-circle 10 (move-circle 10 (make-circle (make-posn 30 30) 45 'red)))))

Anyway my question is simply this: why is there an "else" at all in that conditional?  The function "draw-and-clear-circle" always returns a value of "true", or, if there's something wrong with the definition of the circle structure, an error.  So afaik the "else" would never come into play.

>>28

Assuming you are Nikita, I'd say you are more than skilled enough to work as a developer. You might not be able to use lisp on the job, but you can recognize it's presence in xml, json, and code generation scripts. While some of its manifestations are more verbose and less reliable, it's all still there in spirit: the processing and fully customizable evaluation of structured information. Experience in lisp is handy for using these techniques effectively. And lisp's variety of features overlap in other languages, so it's not hard to move onto others.

If you want experience on your resume, you can look into what types of jobs you would like, and make some demonstration projects using the same languages and platforms. If they want experience with TEAM WORK, you can add some patches to an open source project or something.

The bigotry wont help. If I was a manager, I'd worry about you harassing coworkers and customers that are of jewish ancestry. I do hope you let it go one day, although the spam has been entertaining.

Sincerely,
a jew