defconstrainedfn-arity2-test.clj

(defconstrainedfn doubler
  "Defines a function that doubles its input."
  ([n]
     :requires
     (number? n)
    
     :ensures
     (= (* 2 n) %)

     :body
     (* 2 n))
    
  ([x y]
     :requires
     (every? number? [x y])
           
     :ensures
     (number? %)
     (= (* 2 (+ x y)) %)
  
     :body
     (* 2 (+ x y))))