fizzbuzz.rkt

#lang racket

(require srfi/41)

(define (fizzbuzz-stream)
  (let loop ([n 1])
    (stream-cons
     (match* ((modulo n 3) (modulo n 5))
       [(0 0) "FizzBuzz"]
       [(0 _) "Fizz"]
       [(_ 0) "Buzz"]
       [(_ _) (number->string n)])
     (loop (add1 n)))))

(module+ test
  (require rackunit)
  (check-equal? (stream->list (stream-take 15 (fizzbuzz-stream)))
                '("1" "2" "Fizz" "4" "Buzz" "Fizz" "7" "8" "Fizz" "Buzz" "11" "Fizz" "13" "14" "FizzBuzz")))

(module+ main
  (stream-for-each displayln (stream-take 100 (fizzbuzz-stream))))