-module(print_server).

-export([start/0, get_fun/1]).

start() ->
  spawn(fun() -> server(fun(X) -> X end) end).

get_fun(Server) ->
  Server ! {get, self()},
  receive
    {print_fun, Server, Fun} -> Fun
    after 5000          -> timeout
  end.

server(Fun) ->
  receive
    {set, NewFun} ->
        server(NewFun);
    {get, Whom} ->
        Whom ! {print_fun, self(), Fun},
        server(Fun);
    {say, Value} ->
        io:format("print_server: ~w~n", [Fun(Value)]),
        server(Fun);
    {say, Label, Value} ->
        io:format("~w: ~w~n", [Label, Fun(Value)]),
        server(Fun);
    {quit} ->
        true
  end.