►C211/  H211:   Introduction to Computer Science
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Lecture 12: Unlimited data🔗

This assignment is due on Tuesday, October 1 at 11:59pm. Submit it using Handin as assignment lecture12.

; A Point is (make-point Number Number)
(define-struct point [x y])
 
; A BunchOfPoints is one of:
; - (make-none)
; - (make-some Point BunchOfPoints)
(define-struct none [])
(define-struct some [first rest])

Exercise 1. Define 3 examples of BunchOfPoints. Don’t use the examples from the video.

Exercise 2. Copy the comments below to your Definitions Window. For each of the 6 expressions, say whether it is a BunchOfPoints, and explain why not if not. The first 2 parts are already done for you; follow their pattern.
; 1. (make-some (make-point 1 1) (make-none))
;    is a BunchOfPoints
 
; 2. (make-point (make-some 1 1) (make-none))
;    is not a BunchOfPoints because it is a
;    use of neither make-some nor make-none
 
; 3. (make-some (make-point 70 40)
;               (make-point 30 50))
;
 
; 4. (make-none)
;
 
; 5. (make-some (make-point 30 50)
;               make-none)
;
 
; 6. (make-some
;     (make-point 70 40)
;     (make-some (make-point 30 50)
;                (make-none)))
;

Exercise 3. Here’s the first two steps of the design recipe for count-all-points.
; count-all-points : BunchOfPoints -> Number
; count how many points are in the bunch
(define (count-all-points bop) ...)
Write the template for count-all-points. Make it look like a function called process-bop, and do not put it in a comment.

Exercise 4. Finish designing count-all-points.

Exercise 5. Finish designing this function:
; move-points-up : BunchOfPoints -> BunchOfPoints
; subtract 1 from every Y coordinate
; in the given BunchOfPoints
 
(check-expect
 (move-points-up (make-none))
 (make-none))
 
(check-expect
 (move-points-up
  (make-some (make-point 30 50) (make-none)))
 (make-some (make-point 30 49) (make-none)))
 
(check-expect
 (move-points-up
  (make-some (make-point 70 40)
             (make-some (make-point 30 50) (make-none))))
 (make-some (make-point 70 39)
            (make-some (make-point 30 49) (make-none))))
 
(define (move-points-up bp) ...)

Exercise 6. Using the functions you’ve defined, and the mouse function defined in the video, run the big-bang animation shown.

Exercise 7. Optional: Change mouse to only add points when you click the mouse, as shown at the end of the video.

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