From b214b07a67d48ad9205f63641891ff173ff53fca Mon Sep 17 00:00:00 2001
From: Mike Vink <>
Date: Wed, 19 Apr 2023 12:44:58 +0200
Subject: working on complex package excercise

---
 coding-exercises/2/78/complex-rectangular.rkt | 29 +++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 coding-exercises/2/78/complex-rectangular.rkt

(limited to 'coding-exercises/2/78/complex-rectangular.rkt')

diff --git a/coding-exercises/2/78/complex-rectangular.rkt b/coding-exercises/2/78/complex-rectangular.rkt
new file mode 100644
index 0000000..41e93b6
--- /dev/null
+++ b/coding-exercises/2/78/complex-rectangular.rkt
@@ -0,0 +1,29 @@
+#lang racket
+(provide install-rectangular-package)
+(require "../../../shared/data-directed-programming.rkt")
+
+
+(define (install-rectangular-package put)
+  (define (real-part z) (car z))
+  (define (imag-part z) (cdr z))
+  (define (make-from-real-imag x y) (cons x y))
+  (define (magnitude z) (sqrt (+ (sqr (real-part z))
+                                 (sqr (real-part z)))))
+  (define (angle z)
+    (atan (imag-part z)
+          (real-part z)))
+  (define (make-from-mag-ang r a)
+    (cons (* r (cos a))
+          (* r (sin a))))
+  ;; interface part
+  (define (typtag x)
+    (attach-tag 'rectangular x))
+
+  (put 'real-part '(rectangular) real-part)
+  (put 'imag-part '(rectangular) imag-part)
+  (put 'magnitude '(rectangular) magnitude)
+  (put 'angle '(rectangular) angle)
+  (put 'make-from-real-imag 'rectangular
+       (lambda (x y) (typtag (make-from-real-imag x y))))
+  (put 'make-from-mag-ang 'rectangular
+       (lambda (r a) (typtag (make-from-mag-ang r a)))))
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