# Haskell Filter Function
filt _ []     = []
filt f (x:xs) 
  | f x       = x : filt f xs
  | otherwise = filt f xs

main = do
  let nums = [1..10]
  let odds = filt odd [1..10]
  print $ nums
  print $ odds

# F# Filter Function
let rec filt f = function
    | [] -> []
    | x::xs when f x -> x :: filt f xs
    | x::xs -> filt f xs

[<EntryPoint>]
let main argv =
    let nums = [1..10]
    let odds = filt odd [1..10]
    printfn "%A" nums
    printfn "%A" odds
    0 // return an integer exit code

# Ocaml Filter Function
let rec filt f = function
    | [] -> []
    | x::xs when f x -> x :: filt f xs
    | _::xs -> filt f xs  

let () =
  let nums = List.init 10 (fun x -> x + 1) in
  let odds = filt (fun x -> x mod 2 <> 0) nums in
  List.iter print_int nums;
  List.iter print_int odds