test_lwt.ml

(*
 *Compile with:
 *ocamlfind ocamlc -o test_lwt -thread -linkpkg -package core,lwt,lwt.unix test_lwt.ml
 *Run with:
 *./test_lwt
 *)
open Lwt.Infix
open Core.Std

let rec read_data ic =
  Lwt_io.read_line ic >>= fun v ->
    print_endline ("Data: " ^ v);
    read_data ic

let read_numbers ic =
  let rec loop () = Lwt_io.read_int ic >>= fun v ->
    print_endline ("Int: " ^ (string_of_int v));
    loop ()
  in
  Lwt.async (loop)

let ping oc =
  let rec loop () =
    Lwt_unix.sleep 1.0 >>= fun () ->
      ignore (Lwt_io.write_line oc "Some message");
      let _ = Lwt_io.write_line oc "Ping" in
      loop ()
  in
  Lwt.async (loop)

let pings oc =
  let rec loop () =
    Lwt_unix.sleep 1.0 >>= fun () ->
      ignore (Lwt_io.write_int oc 7);
      loop ()
  in
  Lwt.async (loop)

let other_stuff oc =
  let rec loop () =
    Lwt_unix.sleep 3.0 >>= fun () ->
      let _ = Lwt_io.write_line oc "Some message..." in
      loop ()
  in
  Lwt.async (loop)

let () =
  let (ic, oc) = Lwt_io.pipe () in
  let (ic2, oc2) = Lwt_io.pipe () in
  ignore (Lwt_io.write_line oc "msg1");
  ignore (Lwt_io.write_line oc "msg2");
  ignore (Lwt_io.write_line oc "5");
  ping oc;
  other_stuff oc;
  pings oc2;
  read_numbers ic2;
  Lwt_main.run (read_data ic)