module ChurchPrint

open System

let nil (c:'a->'b->'b) (n:'b) : 'b = n

let cons (x:'a) (xs:('a->'b->'b)->'b->'b) : ('a->'b->'b)->'b->'b =
    fun c n -> c x (xs c n)

let fold (xs:('a->'b->'b)->'b->'b) (c:'a->'b->'b) (n:'b) : 'b =
    xs c n

let toList (xs:('a->'b->'b)->'b->'b) : 'a list =
    fold xs (fun x acc -> x :: acc) []

let printChurchTR (show:'a -> string) (xs:('a->'b->'b)->'b->'b) : unit =
    let rec loop l =
        match l with
        | [] -> ()
        | h :: t ->
            printf "%s" (show h)
            if t <> [] then printf " "
            loop t
    xs |> toList |> loop
    printfn ""

[<EntryPoint>]
let main _ =
    let churchList = cons 1 (cons 2 (cons 3 nil))
    
    printf "Числа: "
    printChurchTR string churchList
    
    let stringList = cons "Hello" (cons "World" (cons "F#" nil))
    
    printf "Строки: "
    printChurchTR id stringList
    
    0