;; Die ersten drei Zeilen dieser Datei wurden von DrRacket eingefügt. Sie enthalten Metadaten
;; über die Sprachebene dieser Datei in einer Form, die DrRacket verarbeiten kann.
#reader(lib "DMdA-beginner-reader.ss" "deinprogramm")((modname morecookies) (read-case-sensitive #f) (teachpacks ()) (deinprogramm-settings #(#f write repeating-decimal #f #t none explicit #f ())))
(: simple-choc chocolate-cookie)
(define simple-choc (make-chocolate-cookie 10 12))
(define double-choc (make-chocolate-cookie 20 12))

; Gewicht eines Schokokekses bestimmten
(: chocolate-cookie-weight (chocolate-cookie -> real))

(check-expect (chocolate-cookie-weight simple-choc) 22)
(check-expect (chocolate-cookie-weight double-choc) 32)

#;(define chocolate-cookie-weight
  (lambda (c)
    ...(chocolate-cookie-chocolate c)
    ...(chocolate-cookie-cookie c)
    ...))

(define chocolate-cookie-weight
  (lambda (c)
    (+ (chocolate-cookie-chocolate c)
       (chocolate-cookie-cookie c))))

; Aus einem Keks einen neuen mit doppelt so hohem Schokoladenanteil erzeugen
(: double-chocolate-in-cookie (chocolate-cookie -> chocolate-cookie))

(check-expect (double-chocolate-in-cookie simple-choc) double-choc)

#;(define double-chocolate-in-cookie
  (lambda (c)
    ...(chocolate-cookie-chocolate c)
    ...(chocolate-cookie-cookie c)
    ...))

; Ergebnis ist Cookie, daher Konstruktor:
#;(define double-chocolate-in-cookie
  (lambda (c)
    (make-chocolate-cookie
    ...(chocolate-cookie-chocolate c)
    ...(chocolate-cookie-cookie c)
    ...)))

; geschickte Kombination:
(define double-chocolate-in-cookie
  (lambda (c)
    (make-chocolate-cookie
      (* 2 (chocolate-cookie-chocolate c))
      (chocolate-cookie-cookie c))))




;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Ein Marmelade-Creme-Keks besteht aus
; - einem Marmeladen-Anteil (real)
; - einem Creme-Anteil (real)
; - einem Keks-Anteil (real)

(define-record-procedures jelly-cream-cookie
  make-jelly-cream-cookie
  jelly-cream-cookie?
  (jelly-cream-cookie-jelly jelly-cream-cookie-cream
                            jelly-cream-cookie-cookie))

(: make-jelly-cream-cookie (real real real -> jelly-cream-cookie))
(: jelly-cream-cookie? (any -> boolean))
(: jelly-cream-cookie-jelly  (jelly-cream-cookie -> real))
(: jelly-cream-cookie-cream  (jelly-cream-cookie -> real))
(: jelly-cream-cookie-cookie (jelly-cream-cookie -> real))

(define simple-jelly-cream (make-jelly-cream-cookie 10 10 12))
(define double-jelly-cream (make-jelly-cream-cookie 15 20 12))


; Gewicht eines Marmeladen-Creme-Kekses bestimmen
(: jelly-cream-cookie-weight (jelly-cream-cookie -> real))

(check-expect (jelly-cream-cookie-weight simple-jelly-cream) 32)
(check-expect (jelly-cream-cookie-weight double-jelly-cream) 47)

#;(define jelly-cream-cookie-weight
  (lambda (c)
    ...))

#;(define jelly-cream-cookie-weight
  (lambda (c)
    ...(jelly-cream-cookie-jelly c)
    ...(jelly-cream-cookie-cream c)
    ...(jelly-cream-cookie-cookie c)))

(define jelly-cream-cookie-weight
  (lambda (c)
    (+ (jelly-cream-cookie-jelly c)
       (jelly-cream-cookie-cream c)
       (jelly-cream-cookie-cookie c))))

; Kekse als eine Einheit: gemischte Daten!

; Ein Keks ist eins der folgenden:
; - ein Schokokeks (chocolate-cookie)
; - ein Marmeladen-Creme-Keks (jelly-cream-cookie)
; Name: cookie

(define cookie
  (signature (mixed chocolate-cookie
                    jelly-cream-cookie)))

;(define onetwothree (signature (one-of 1 2 3)))

; Gewicht eines Kekses bestimmen
(: cookie-weight (cookie -> real))

(check-expect (cookie-weight simple-choc) 22)
(check-expect (cookie-weight double-choc) 32)
(check-expect (cookie-weight simple-jelly-cream) 32)
(check-expect (cookie-weight double-jelly-cream) 47)

#;(define cookie-weight
  (lambda (c)
    ...))

; Fallunterscheidung weil zwei Arten von Eingabedaten:
#;(define cookie-weight
  (lambda (c)
    (cond (... ...)
          (... ...))))

; Setze "Signaturprädikate" in die Alternativen ein:
#;(define cookie-weight
  (lambda (c)
    (cond ((chocolate-cookie? c)   ...)
          ((jelly-cream-cookie? c) ...))))

(define cookie-weight
  (lambda (c)
    (cond ((chocolate-cookie? c)   (chocolate-cookie-weight c))
          ((jelly-cream-cookie? c) (jelly-cream-cookie-weight c)))))