University of British Columbia CPSC 110 Lab 5

;; CPSC 110 - Helpers Lab



(require spd/tags)

(require 2htdp/image)

(require 2htdp/universe)



(@assignment lab-05)

(@cwl ???)



;; 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