(require spd/tags) (require 2htdp/image) (require 2htdp/universe)

(@assignment lab-05) (@csid ???)

;; Problem 1

;; Complete the design of a function called pyramid that takes a natural ;; number n and an image, and constructs an n-tall, n-wide pyramid of ;; copies of that image.

;; For instance, a 3-wide pyramid of cookies would look like this:

;(bitmap/url ; "https://edx-course-spdx-kiczales.s3.amazonaws.com/HTC/lab/cookies-pyramid.png") ; (run in interactions window)

;; Constants

(define COOKIES (bitmap/url "https://edx-course-spdx-kiczales.s3.amazonaws.com/HTC/lab/cookies.png")) (define SQUARE (square 10 "solid" "blue"))

;; ====================================================================== ;; Data Definitions

(@htdd Natural) ;; Natural is one of: ;; - 0 ;; - (add1 Natural) ;; interp. a natural number (define N0 0) ;0 (define N1 (add1 N0)) ;1 (define N2 (add1 N1)) ;2

(@dd-template-rules one-of atomic-distinct compound self-ref) (define (fn-for-natural n) (cond [(zero? n) (...)] [else (... n ; n is added because it's often useful (fn-for-natural (sub1 n)))]))

;; ========== ;; Functions

(@problem 1) (@htdf pyramid) (@signature Natural Image -> Image) ;; produce an n-tall, n-wide pyramid of the given image (check-expect (pyramid 0 COOKIES) empty-image) (check-expect (pyramid 1 SQUARE) SQUARE) (check-expect (pyramid 3 COOKIES) (above COOKIES (beside COOKIES COOKIES) (beside COOKIES COOKIES COOKIES)))

(define (pyramid n i) empty-image) ; stub

;; Problem 2 ;; ;; Consider a test tube filled with solid blobs and bubbles. Over time the ;; solids sink to the bottom of the test tube, and as a consequence the bubbles ;; percolate to the top. ;; ;; Complete the design of a world program that displays the test tube of blobs. ;; Initially, the test tube is empty, but we can add solid blobs and bubbles by ;; pressing the "s" and "b" keys respectively. Pressing the spacebar will sink ;; each solid blob by one. ;; ;; We have completed most of this program already. All you will need to do is ;; complete the sink function (a helper function for handle-key). This function ;; will consume a list of blobs and sinks each solid blob by one. You can assume ;; that a solid blob will sink past any neighbour just below it.

(@htdw ListOfBlob) ;; CONSTANTS ============================

(define WIDTH 300) (define HEIGHT 500)

(define TUBE-WIDTH 50) (define TUBE (overlay/align/offset "middle" "bottom" (rectangle TUBE-WIDTH (- HEIGHT TUBE-WIDTH) "solid" "silver") 0 (/ TUBE-WIDTH 2) (circle (/ TUBE-WIDTH 2) "solid" "silver")))

(define MTS (overlay/align "middle" "bottom" TUBE (empty-scene WIDTH HEIGHT)))

(define X-CTR (/ WIDTH 2))

(define BLOB-RADIUS (* 0.4 TUBE-WIDTH)) (define SOLID (circle BLOB-RADIUS "solid" "black")) (define BUBBLE (circle BLOB-RADIUS "outline" "blue"))

;; DATA DEFINITIONS ====================

(@htdd Blob) ;; Blob is one of: ;; - "solid" ;; - "bubble" ;; interp. a gelatinous blob, either a solid or a bubble ;; Examples are redundant for enumerations

(@dd-template-rules one-of atomic-distinct atomic-distinct) (define (fn-for-blob b) (cond [(string=? b "solid") (...)] [(string=? b "bubble") (...)]))

(@htdd ListOfBlob) ;; ListOfBlob is one of: ;; - empty ;; - (cons Blob ListOfBlob) ;; interp. a sequence of blobs in a test tube, listed from top to bottom. (define LOB0 empty) ; empty test tube (define LOB2 (cons "solid" (cons "bubble" empty))) ; solid blob above a bubble

(@dd-template-rules one-of atomic-distinct compound ref self-ref) (define (fn-for-lob lob) (cond [(empty? lob) (...)] [else (... (fn-for-blob (first lob)) (fn-for-lob (rest lob)))]))

;; FUNCTIONS ===========================

(@htdf main) (@signature ListOfBlob -> ListOfBlob) ;; start the world program with (main empty)

(@template htdw-main) (define (main lob) (big-bang lob (to-draw render-lob) (on-key handle-key)))

(@htdf render-lob) (@signature ListOfBlob -> Image) ;; renders the list of blobs on MTS (check-expect (render-lob empty) MTS) (check-expect (render-lob (cons "bubble" (cons "solid" (cons "bubble" empty)))) (overlay/align "middle" "bottom" (above BUBBLE SOLID BUBBLE) MTS))

(@template fn-composition) (define (render-lob lob) (overlay/align "middle" "bottom" (render-blobs lob) MTS))

(@htdf render-blobs) (@signature ListOfBlob -> Image) ;; renders the list of blobs in vertical line (check-expect (render-blobs empty) empty-image) (check-expect (render-blobs (cons "bubble" (cons "solid" (cons "solid" empty)))) (above BUBBLE SOLID SOLID))

(@template ListOfBlob) (define (render-blobs lob) (cond [(empty? lob) empty-image] [else (above (render-blob (first lob)) (render-blobs (rest lob)))]))

(@htdf render-blob) (@signature Blob -> Image) ;; produce the image for the given blob (check-expect (render-blob "bubble") BUBBLE) (check-expect (render-blob "solid") SOLID)

(@template Blob) (define (render-blob b) (cond [(string=? b "solid") SOLID] [(string=? b "bubble") BUBBLE]))

(@htdf handle-key) (@signature ListOfBlob KeyEvent -> ListOfBlob) ;; add blobs on "s", "b" and sink on " " (check-expect (handle-key (cons "bubble" (cons "solid" empty)) "s") (cons "solid" (cons "bubble" (cons "solid" empty)))) (check-expect (handle-key (cons "bubble" empty) "b") (cons "bubble" (cons "bubble" empty))) (check-expect (handle-key (cons "solid" (cons "bubble" empty)) " ") (cons "bubble" (cons "solid" empty)))

(@template KeyEvent) (define (handle-key lob ke) (cond [(key=? "s" ke) (cons "solid" lob)] [(key=? "b" ke) (cons "bubble" lob)] [(key=? " " ke) (sink lob)] [else lob]))

(@problem 2) (@htdf sink) (@signature ListOfBlob -> ListOfBlob) ;; produce a list of blobs that sinks the given solid blobs by one ; !!! (check-expect (sink empty) empty) (check-expect (sink (cons "bubble" (cons "solid" (cons "bubble" empty)))) (cons "bubble" (cons "bubble" (cons "solid" empty)))) (check-expect (sink (cons "solid" (cons "solid" (cons "bubble" empty)))) (cons "bubble" (cons "solid" (cons "solid" empty)))) (check-expect (sink (cons "solid" (cons "bubble" (cons "bubble" empty)))) (cons "bubble" (cons "solid" (cons "bubble" empty))))

;; On-Ground Students: ;; As PRE-LAB: Complete these three check-expects, then uncomment them.

;; Online Students: ;; Complete these three check-expects, then uncomment them.

;(check-expect (sink (cons "solid" (cons "bubble" (cons "solid" empty)))) ; ...) ;(check-expect (sink (cons "bubble" (cons "solid" (cons "solid" empty)))) ; ...) ;(check-expect (sink (cons "solid" ; (cons "solid" ; (cons "bubble" (cons "bubble" empty))))) ; ...)

(define (sink lob) lob) ;stub

When you give the answer please use the codes from dr. Racket