proglang week 5 tests

pemis.rkt

#lang racket

(require "hw4.rkt")

;; Tests Start Here

; These definitions will work only after you do some of the problems
; so you need to comment them out until you are ready.
; Add more tests as appropriate, of course.

; 1
(print (equal? (sequence 3 11 2) '(3 5 7 9 11)))
(print (equal? (sequence 3 8 3) '(3 6)))
(print (equal? (sequence 3 2 1) '()))
(newline)

; 2
(print (equal? (string-append-map '() "suffix") '()))
(print (equal? (string-append-map '("eblo" "sobachka") "suffix")
               '("eblosuffix" "sobachkasuffix")))
(newline)

; 3
(print (equal? (list-nth-mod '(1 2 3 4 5) 14) 5))
(print (equal? (list-nth-mod '(1 2 3) 14) 3))
(print (equal? (list-nth-mod '(1 2 3 4 5 6 7) 25) 5))
(newline)

; 4
(define ones (λ () (cons 1 ones)))
(define onetwos
  (letrec ([ones (λ () (cons 1 twos))]
           [twos (λ () (cons 2 ones))])
    ones))

(print (equal? (stream-for-n-steps ones 5) '(1 1 1 1 1)))
(print (equal? (stream-for-n-steps onetwos 5) '(1 2 1 2 1)))
(newline)

; 5
(print (equal? (stream-for-n-steps funny-number-stream 10)
               '(1 2 3 4 -5 6 7 8 9 -10)))
(newline)

; 6
(print (equal? (stream-for-n-steps dan-then-dog 5)
               '("dan.jpg" "dog.jpg" "dan.jpg" "dog.jpg" "dan.jpg")))
(newline)

; 7
(print (equal? (stream-for-n-steps (stream-add-zero ones) 3)
               '((0 . 1) (0 . 1) (0 . 1))))
(print (equal? (stream-for-n-steps (stream-add-zero onetwos) 3)
               '((0 . 1) (0 . 2) (0 . 1))))
(newline)

; 8
(print (equal? (stream-for-n-steps (cycle-lists '(1 2 3) '("a" "b")) 8)
               '((1 . "a") (2 . "b") (3 . "a") (1 . "b") (2 . "a") (3 . "b") (1 . "a") (2 . "b"))))
(newline)

; 9
(print (equal? (vector-assoc 5 (list->vector '((2 . 8) (5 . 7))))
               '(5 . 7)))
(print (equal? (vector-assoc 5 (list->vector '((2 . 8) (5 . 3) (5 . 7))))
               '(5 . 3)))
(print (equal? (vector-assoc 5 (list->vector '((2 . 8))))
               #f))
(newline)

; 10
(print (equal? ((cached-assoc '((2 . 8) (5 . 7)) 3) 5)
               '(5 . 7)))
(print (equal? ((cached-assoc '((2 . 8) (5 . 3) (5 . 7)) 1) 5)
               '(5 . 3)))
(print (equal? ((cached-assoc '((2 . 8)) 3) 5)
               #f))
(newline)