s c h e m a t i c s : c o o k b o o k

(define (monster-string n)
  (let ((text (if (= n 1) (list "is" 1 "")
              (list "are" n "s"))))
    (printf "There ~a ~a monster~a approaching"
            (car text) (cadr text) (caddr text))))

> (monster-string 1)
There is 1 monster approaching
> (monster-string 15)
There are 15 monsters approaching
> 

(define (is-are n)
  (if (= n 1) "is" "are"))

(define (plural n)
  (if (= n 1) "" "s"))

(define (monster-string2 n)
  (printf "There ~a ~a monster~a approaching"
          (is-are n)
          n
          (plural n)))

> (monster-string2 1)
There is 1 monster approaching
> (monster-string2 15)
There are 15 monsters approaching
>