Fizzbuzz By Computation Expression

fizzbuzz.fsx

// builder
let fb_return = fun v ->
  match v with
  | (x, "") -> x.ToString()
  | (_, s) -> s
  
type FizzBuzzBuilder() =
  member this.Return v = fb_return v

let fizzbuzz = FizzBuzzBuilder()

// predicator
let fizz = fun x ->
  match x with
  | x when x % 3 = 0 -> "Fizz"
  | _ -> ""
  
let buzz = fun x ->
  match x with
  | x when x % 5 = 0 -> "Buzz"
  | _ -> ""

// test
[1..30] 
|> List.map(fun x -> fizzbuzz {
  return (x, fizz(x) + buzz(x))
}) 
|> Seq.iter(fun x -> printfn "%s" x)