Rename stream-to-list to stream-take-n

Author: ramsayleung

chapter3/exercise3-50.rkt

@@ -18,13 +18,13 @@
              (define s1 (list-to-stream '(1 2 3 4)))
              (define s2 (list-to-stream '(10 20 30 40)))
              (define added (stream-map + s1 s2))
-             (check-equal? (stream-to-list added 4) '(11 22 33 44))
+             (check-equal? (stream-take-n added 4) '(11 22 33 44))
              )
 
   (test-case "Test for different length streams(stop at shortest)"
              (define s1 (list-to-stream '(1 2)))
              (define s2 (list-to-stream '(10 20 30 40)))
              (define added (stream-map + s1 s2))
-             (check-equal? (stream-to-list added 4) '(11 22))
+             (check-equal? (stream-take-n added 4) '(11 22))
              )
   )

chapter3/exercise3-54.rkt

@@ -16,10 +16,10 @@
              (define s2 (list-to-stream '(3 4 5 6)))
              (define s3 (mul-streams s1 s2))
              (check-equal? (stream-ref s3 2) 20)
-             (check-equal? (stream-to-list s3 4) '(6 12 20 30))
+             (check-equal? (stream-take-n s3 4) '(6 12 20 30))
              )
   (test-case "Test for factorials"
-             (check-equal? (stream-to-list factorials 5) '(1 2 6 24 120))
+             (check-equal? (stream-take-n factorials 5) '(1 2 6 24 120))
              ;; n = 0, n+1=1 的阶乘是1
              ;; n = 1, n+1=2 的阶乘是2
              ;; n = 2, n+1=3 的阶乘是6

chapter3/exercise3-55.rkt

@@ -11,6 +11,6 @@
 
   (test-case "Test for partial-sums"
              (define s1 (partial-sums integers))
-             (check-equal? (stream-to-list s1 5) '(1 3 6 10 15))
+             (check-equal? (stream-take-n s1 5) '(1 3 6 10 15))
   )
 )

chapter3/exercise3-56.rkt

@@ -27,9 +27,9 @@
              (define s1 (list-to-stream '(1 2 3 5 7)))
              (define s2 (list-to-stream '(2 4 5 8 9)))
              (define s3 (merge s1 s2))
-             (check-equal? (stream-to-list s3 10) '(1 2 3 4 5 7 8 9))
+             (check-equal? (stream-take-n s3 10) '(1 2 3 4 5 7 8 9))
              )
   (test-case "Test for S"
-             (check-equal? (stream-to-list S 20) '(1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 32 36))
+             (check-equal? (stream-take-n S 20) '(1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 32 36))
              )
   )

chapter3/exercise3-58.rkt

@@ -13,8 +13,8 @@
   (test-case "Test for expand"
              (define x (expand 3 8 10))
              ;; 3/8 = 0.375 (有限小数)
-             (check-equal? (stream-to-list x 10) '(3 7 5 0 0 0 0 0 0 0))
+             (check-equal? (stream-take-n x 10) '(3 7 5 0 0 0 0 0 0 0))
 
              (define s (expand 1 7 10))
              ;; (expand 1 7 10) 对应 1/7 = 0.142857142857... (循环小数)
-             (check-equal? (stream-to-list s 10) '(1 4 2 8 5 7 1 4 2 8))))
+             (check-equal? (stream-take-n s 10) '(1 4 2 8 5 7 1 4 2 8))))

chapter3/exercise3-67.rkt

@@ -35,7 +35,7 @@
   (test-case "Test for full-pairs"
              (define s1 (list-to-stream '(1 2 3)))
              (define s2 (list-to-stream '(1 2 3)))
-             (define int-pairs (stream-to-list (full-pairs s1 s2) 9))
+             (define int-pairs (stream-take-n (full-pairs s1 s2) 9))
              (check-equal? int-pairs '((1 1) (1 2) (2 2) (2 1) (2 3) (1 3) (3 3) (3 1) (3 2)))
              )
   )

chapter3/exercise3-69.rkt

@@ -29,7 +29,7 @@
              (define s1 (list-to-stream '(1 2 3)))
              (define s2 (list-to-stream '(1 2 3)))
              (define s3 (list-to-stream '(1 2 3)))
-             (check-equal? (stream-to-list (triples s1 s2 s3) 20) '((1 1 1)
+             (check-equal? (stream-take-n (triples s1 s2 s3) 20) '((1 1 1)
                                                                     (1 1 2)
                                                                     (2 2 2)
                                                                     (1 2 2)
@@ -43,6 +43,6 @@
                         (define s1 (stream-enumerate-interval 1 10))
                         (define s2 (stream-enumerate-interval 1 10))
                         (define s3 (stream-enumerate-interval 1 10))
-                        (check-equal? (stream-to-list (pythagorean (triples s1 s2 s3)) 2) '((3 4 5) (6 8 10)))
+                        (check-equal? (stream-take-n (pythagorean (triples s1 s2 s3)) 2) '((3 4 5) (6 8 10)))
                         )
              ))

chapter3/exercise3-70.rkt

@@ -43,15 +43,15 @@
              (define s2 (list-to-stream '(2 -4 5 8 9)))
              (define weight (lambda (x) (abs x)))
              (define s3 (merge-weighted s1 s2 weight))
-             (check-equal? (stream-to-list s3 10) '(1 2 2 3 -4 5 5 7 8 9))
+             (check-equal? (stream-take-n s3 10) '(1 2 2 3 -4 5 5 7 8 9))
              )
 
   (test-case "Test for pairs-weighted with weight = i+j"
              (define s1 (list-to-stream '(1 2 3)))
              (define s2 (list-to-stream '(1 2 3)))
              (define weight (lambda (pair) (+ (car pair) (cadr pair))))
              (define s3 (pairs-weighted s1 s2 weight))
-             (check-equal? (stream-to-list s3 10) '((1 1) (1 2) (1 3) (2 2) (2 3) (3 3)))
+             (check-equal? (stream-take-n s3 10) '((1 1) (1 2) (1 3) (2 2) (2 3) (3 3)))
              )
 
   (test-case "Test for pairs-weighted with weight = 2j + 3j + 5ij"
@@ -61,5 +61,5 @@
                                                 (* 3 j)
                                                 (* 5 i j)))))
              (define result (pairs-weighted not-div-by-2-3-5 not-div-by-2-3-5 weight))
-             (check-equal? (stream-to-list result 5) '((1 1) (1 7) (1 11) (1 13) (1 17))))
+             (check-equal? (stream-take-n result 5) '((1 1) (1 7) (1 11) (1 13) (1 17))))
   )

chapter3/infinite-stream.rkt

@@ -67,13 +67,13 @@
   (test-case "Test for interleave"
              (define s1 (list-to-stream '(1 2 3 4 5)))
              (define s2 (list-to-stream '(6 7 8 9 10)))
-             (check-equal? (stream-to-list (interleave s1 s2) 10) '(1 6 2 7 3 8 4 9 5 10))
+             (check-equal? (stream-take-n (interleave s1 s2) 10) '(1 6 2 7 3 8 4 9 5 10))
              )
 
   (test-case "Test for pairs"
              (define s1 (list-to-stream '(1 2 3)))
              (define s2 (list-to-stream '(1 2 3)))
-             (define int-pairs (stream-to-list (pairs s1 s2) 4))
+             (define int-pairs (stream-take-n (pairs s1 s2) 4))
              (check-equal? int-pairs '((1 1) (1 2) (2 2) (1 3)))
              )
   )

chapter3/stream.rkt

@@ -73,12 +73,12 @@
        (stream-enumerate-interval (+ low 1) high))))
 
 ;; Testing utility functions
-(define (stream-to-list stream n)
+(define (stream-take-n stream n)
   (if (or (= n 0)
           (stream-null? stream))
       '()
       (cons (stream-car stream)
-            (stream-to-list (stream-cdr stream)
+            (stream-take-n (stream-cdr stream)
                             (- n 1)))))
 (define (list-to-stream lst)
   (if (null? lst)
@@ -152,13 +152,13 @@
   (test-case "Test for stream-map"
              (define s3 (list-to-stream '(1 2 3 4 5)))
              (define squared (stream-map (lambda (x) (* x x)) s3))
-             (check-equal? (stream-to-list squared 5) '(1 4 9 16 25))
+             (check-equal? (stream-take-n squared 5) '(1 4 9 16 25))
              )
 
   (test-case "Test for stream-filter"
              (define s3 (list-to-stream '(1 2 3 4 5)))
              (define even (stream-filter even? s3))
-             (check-equal? (stream-to-list even 5) '(2 4))
+             (check-equal? (stream-take-n even 5) '(2 4))
              )
 
   (test-case "Test for stream-for-each"
@@ -175,6 +175,6 @@
 
   (test-case "Test for stream-enumerate-interval"
              (define s (stream-enumerate-interval 5 10))
-             (check-equal? (stream-to-list s 10) '(5 6 7 8 9 10))
+             (check-equal? (stream-take-n s 10) '(5 6 7 8 9 10))
              )
   )