Erlang Do While Loop

% -*- coding: utf8 -*-
-module(main).
-export([main/0]).

main() ->
    Block =
        fun() ->
            U = erlang:unique_integer([positive, monotonic]),
            io:format("~p~n", [U]),
            U
        end,
    Pred =
        fun(U) ->
            U < 3
        end,
    do_while(Block, Pred).

do_while(Block, Predicate) ->
    case Predicate(Block()) of
        true -> do_while(Block, Predicate);
        false -> ok
    end.