FizzBuzz in types

fizzbuzz.fs

type Fizzable = Plain of int
              | Fizzy
              | Buzzy
              | FizzyBuzzy

let toFizzable n :Fizzable =
   match n with
   | _ when (n % 3) = 0 && n % 5 = 0 -> FizzyBuzzy
   | _ when n % 3 = 0 -> Fizzy
   | _ when 0 = n % 5 -> Buzzy
   | _ -> Plain(n)

let toString n =
  match n with
  | Fizzy -> "Fizz"
  | Buzzy -> "Buzz"
  | FizzyBuzzy -> "FizzBuzz"
  | Plain(i) -> i.ToString()

[1..100]
|> List.map (toFizzable >> toString)