>>21
書き直してみた
もはや最速DSLっぽい何かに…

let if_true_then flist x =
  let bind z f =
    match z |> fst |> f with
    |(false, _) -> z
    |(true, y) -> (fst z, y)

  List.fold bind (x, string x) flist |> snd


let Fizz x = (x%3=0, "Fizz")
let Buzz x = (x%5=0, "Buzz")
let FizzBuzz x = (x%15=0, "FizzBuzz")

[1..50]
|> List.map (if_true_then [Fizz; Buzz; FizzBuzz])
|> List.iter (fun x -> printfn "%s" x)