;; data definitions for the car order

;; ORDER
(define-struct order (customer car price date))
;; An Order is a (make-order Customer Car PosInt Date)
;; INTERP:
;; customer is the customer ordering the car
;; car is the car being ordered
;; price is the price, in USD (assumed no cents :-)
;; date is the date of the order

;; Template
;; order-fn : Order -> ??
(define (order-fn o)
  (...
    (order-customer o)
    (order-car o)
    (order-price o)
    (order-date o)))

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;; Customer
(define-struct customer (last first address)
;; A Customer is a (make-customer String String Address)
;; interp:
;; last, first are the customer's last and first names
;; address is the customer's address (which one? mailing? delivery?
  ;; permanent?)

;; Template
;; customer-fn : Customer -> ??
(define (customer-fn c)
  (...
    (customer-last c)
    (customer-first c)
    (customer-address c)))

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;; Car
(define-struct used-car (owner))
(define-struct new-car (ndoors ncyls sunroof? int-color ext-color)

;; A Car is one of
;; -- (make-used-car Customer)
;; -- (make-new-car NDoors NCyls Boolean PaintColor PaintColor)

;; interp:
;; for a used car:
;; -- owner is the previous owner

;; for a new car:
;; -- ndoors is the number of doors
;; -- ncyls is the number of cylinders
;; -- sunroof? tells whether or not the car has a sunroof
;; -- int-color and ext-color are interior and exterior colors of the
;;    car.

;; Template:
;; car-fn : Car -> ??
(define (car-fn c)
  (cond
    [(used-car? c)
     (... (used-car-owner c))]
    [(new-car? c)
     (... (new-car-ndoors c)
       (new-car-ncyls c)
       (new-car-sunroof? c)
       (new-car-int-color c)
       (new-car-ext-color c))]))

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;; Address and Date will be defined elsewhere (by the "large existing
;; system")

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;; An NDoors is one of
;; -- 2
;; -- 4

;; Template:
;; ndoors-fn : NDoors -> ??
(define (ndoors-fn n)
  (cond
    [(= n 2) ...]
    [(= n 4) ...]))

;; NCyls similar