ex: do ex 2.48

1 files changed, 35 insertions, 0 deletions

diff --git a/ex/2/48.rkt b/ex/2/48.rkt
new file mode 100644
index 0000000..50b4984
--- /dev/null
+++ b/ex/2/48.rkt
@@ -0,0 +1,35 @@
+;;;; License: CC0-1.0
+
+#lang racket
+
+(provide make-segment
+         start-segment
+         end-segment)
+
+(define (make-segment start end)
+  (cons start end))
+
+(define (start-segment s)
+  (car s))
+
+(define (end-segment s)
+  (cdr s))
+
+;;; tests
+
+(module+ tests
+  (require rackunit
+           "46.rkt")
+
+  (define v-start (make-vect 1 2))
+  (define v-end (make-vect 3 4))
+
+  ;; test make-segment
+  (define seg (make-segment v-start v-end))
+  (check-equal? (car seg) v-start)
+  (check-equal? (cdr seg) v-end)
+
+  ;; test start-segment
+  (check-equal? (start-segment seg) v-start)
+  (check-equal? (end-segment seg) v-end)
+  "all tests ran")