# a5q2 - void) ; ;; Effects: ;; Changes one to original value...

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;; The first three lines of this file were inserted by DrScheme. They record metadata ;; about the language level of this file in a form that our tools can easily process. #reader(lib "htdp-advanced-reader.ss" "lang")((modname a5q2) (read-case-sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor repeating-decimal #t #t none #f ()))) ;;Assignment 5 Question 2 ;; Ru Wang r46wang 20319247 ;; a5q2 ;; State variables: ;; one: any ;; holds the first value, initially (define one 2) ;; two: any ;; holds the second value, initially (define two 3) ;; three: any ;; holds the third value, initially (define three 1) ;; shift: (void) -> (void) ; ;; this function neither consumes or produces anything. (consumes void and produces

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Unformatted text preview: void) ; ;; Effects: ;; Changes one to original value of three ;; Change two to original value of one ;; Change three to original value of two ; ;; Example: after the function has been called, one will contain the initial value of three, two will contain the initial value of one, and three will contain the initial value of two. ; (define (shift) (local [(define x one)] (begin (set! one three) (set! three two) (set! two x)))) ;; Tests: (check-expect (begin (set! one 'a) (set! three 'b) (shift) (equal? one 'b)) true) (check-expect (begin (set! two 'a) (set! one 'b) (shift) (equal? two 'b)) true) (check-expect (begin (set! three 'a) (set! two 'b) (shift) (equal? three 'b)) true)...
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## a5q2 - void) ; ;; Effects: ;; Changes one to original value...

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