contract example

foo.rkt

;; Step 1
(define (valid? a)
  (< a 10))

(define/contract (foo a b)
  (->i ([x valid?] [y any/c]) any)
  (+ a b))

;; Step 2
(define (valid? max a)
  (< a max))

(define/contract (foo a b)
  (->i ([x (curry valid? 10)] [y any/c]) any)
  (+ a b))

;; Step 3
(define (valid? max a)
  (< a max))

(define/contract (foo a b)
  (->i ([x (y) (curry valid? y)] [y any/c]) any)
  (+ a b))