RacketLab3

; Lab 3
(define WPI_ID "ajli") ; please put in your username, the text before the @ in your email address

; ; Problem 1
; ; Given the following data definition for Food and SpecialLunch
; ; Write a function that gets the calories of the drink in the lunch
; ; pay special attention to the interpretation of the SpecialLunch


(define-struct food (name calories healthy?))
; a Food is a (make-food String Natural Boolean)
; interp.
; - name is the name of the food
; - calories is the number of calories in 1 serving of this food
; - true if the food is considered healthy

; Examples(Defining Variables):
(define PIZZA (make-food "Pizza" 350 #false))
(define CHIPS (make-food "Chips" 210 #false))
(define SPORTS-DRINK (make-food "Electromight" 90 #true))
(define PUDDING (make-food "Pudding" 110 #false))

; Template:
#;
(define (food-fcn a-food)
  (...
   (food-name a-food)
   (food-calories a-food)
   (food-healthy? a-food)))

(define-struct splunch (entree side drink dessert))
; a SpecialLunch is a (make-splunch Food Food Food Food)
; interp.
; - entree is the primary food item and has 2 servings
; - side is a secondary food item and has 1 serving
; - drink is a liquid food item and has 3 servings if it is healhy and 1 if it is not
; - dessert is a sweet food item and we don't count/consider its calories if it is healthy

; Example:
(define GRAB-N-GO (make-splunch PIZZA CHIPS SPORTS-DRINK PUDDING))

; Template:
#;
(define (splunch-fcn a-splunch)
  (...
   (splunch-entree a-splunch)
   (splunch-side a-splunch)
   (splunch-drink a-splunch)
   (splunch-dessert a-splunch)))

; Step 1:
; drink-calories : SpecialLunch -> Natural
; consumes a special lunch
; produces the number of calories in the drink of the lunch using the logic in the SpecialLunch interp.
; stub:
;(define (drink-calories a-splunch) 0)

; Step 2:
(check-expect (drink-calories GRAB-N-GO) 270)
(check-expect (drink-calories (make-splunch
                               PIZZA
                               CHIPS
                               (make-food "Soda" 200 #false)
                               PUDDING))
              200)
; STEP 3:
; (define (drink-calories a-splunch)
; (... (food-healthy? (splunch-drink a-splunch))
; (food-calories (splunch-drink a-splunch)) ))


; Step 4:
(define (drink-calories a-splunch)
(if (food-healthy? (splunch-drink a-splunch))
(* 3 (food-calories (splunch-drink a-splunch)))
(food-calories (splunch-drink a-splunch))))

; Step 5 Test and Debug (More Tests):
(check-expect (drink-calories GRAB-N-GO) 270)

(check-expect (drink-calories (make-splunch
PIZZA
CHIPS
(make-food "Soda" 200 #false)
PUDDING))
200)

(check-expect (drink-calories (make-splunch
PIZZA
CHIPS
(make-food "Water" 0 #true)
PUDDING))
0)

(check-expect (drink-calories (make-splunch
PIZZA
CHIPS
(make-food "Juice" 120 #true)
PUDDING))
360)

(check-expect (drink-calories (make-splunch
PIZZA
CHIPS
(make-food "Milkshake" 250 #false)
PUDDING))
250)

; ; Problem 2
; ; Implement the following function `strings-lengths`
; ; Using the ListOfString and ListOfNumber definitions from lecture


; Step 1: strings-lengths: ListOfString -> ListOfNumber
; consumes a list of strings
; produces a list of the length of each string in the same order
;(define (strings-lengths a-los) empty)

; Examples Step 2:
(check-expect (strings-lengths (cons "a" (cons "bb" (cons "ccc" (cons "dddd" empty)))))
                              (cons 1 (cons 2 (cons 3 (cons 4 empty)))))
;Step 3:
; (define (strings-lengths a-los)
; (cond [(empty? a-los) empty]
; [else (cons (... (first a-los)) (strings-lengths (... a-los)))]))

;Step 4:
(define (strings-lengths a-los)
(cond [(empty? a-los) empty]
[else (cons (string-length (first a-los)) (strings-lengths (rest a-los)))]))


;Step 5
(check-expect (strings-lengths (cons "a" (cons "bb" (cons "ccc" (cons "dddd" empty)))))
(cons 1 (cons 2 (cons 3 (cons 4 empty)))))


(check-expect (strings-lengths (cons "hello" (cons "world" (cons "!" empty))))
(cons 5 (cons 5 (cons 1 empty))))

(check-expect (strings-lengths empty) empty)