data transport by function definitions?

crazy.clj

;; We define a product record as a series of explicitly-defined function return values.
;;   - This only convey data, not execution
;;   - It can reference itself in a sensible way
;;   - Consumers aren't concerned about message formatting, simply whether or not
;;     a given function is defined.



(defpoints SKU12345

  (defpoint com.example.seller [this]
    {:email "seller@example.com"
     :name "Example Merchant Inc."})

  (defpoint com.ebay.item.title [country] "Apple iPad")

  (defpoint com.ebay.item.shipping-policy [:com.ebay.countries.germany]
    {:processing-days 3
     :shipping-type :expedited
     :shipping-cost 0})

  (defpoint com.ebay.item.shipping-policy [:com.ebay.countries.uk]
    {:processing-days 3
     :shipping-type :standard
     :shipping-cost 10})

  (defpoint com.ebay.item.paypal-email [country] (-> this com.example.seller :email)))



;; (com.ebay.title :com.ebay.countries.germany SKU12345) --> "Apple iPad"
;; (com.ebay.title :com.ebay.countries.uk SKU12345) --> "Apple iPad"
;; (com.ebay.title :com.ebay.countries.japan SKU12345) --> "Apple iPad"
;;
;; (com.ebay.item.shipping-policy SKU12345 :com.ebay.countries.uk) -->
;;    {:processing-days 3
;;     :shipping-type :standard
;;     :shipping-cost 10}
;;
;; (com.ebay.item.seller-email SKU12345) --> "seller@example.com"
;;
;; (com.ebay.item.return-policy SKU12345) --> ERROR, undefined function point.
;;     OR could use some default value here.