req.ml

open Lwt
(* cannot load this file up in utop without the next two lines *)
(* #require "conduit"
 * #require "conduit-lwt-unix" *)
open Conduit
open Conduit_lwt_unix

let resolve_addr (s: string) : endp Lwt.t =
  let open Resolver_lwt_unix in
  let uri = Uri.of_string s in
  Resolver_lwt.resolve_uri ~uri system

let client_of_addr (s: string) : client Lwt.t =
  resolve_addr s >>= endp_to_client ~ctx:default_ctx

(* TODO: errror handling etc. Conflicts with Lwt_io.with_connection? *)
let with_connection (s: string) (f : ic -> oc -> 'a Lwt.t) : 'a Lwt.t =
  let open Lwt_io in
  client_of_addr s >>= fun cl ->
  connect ~ctx:default_ctx cl >>= fun (_,ic,oc) ->
  f ic oc >>= fun r ->
  close oc >>= fun _ ->
  return r