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#lang racket
(provide install-rectangular-package)
(require "../../../shared/data-directed-programming.rkt")
(define (install-rectangular-package apply-generic 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) (apply-generic 'sqrt (+ (apply-generic 'sqr (real-part z))
(apply-generic 'sqr (real-part z)))))
(define (angle z)
(apply-generic '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))))
'done)
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