iter

after.ml

let get_follower ~access_token ~screen_name ?(count=5000) ?(wait=true) () =
  let base_uri = "https://api.twitter.com/1.1/followers/ids.json" in
  let cursor = ref (-1) in
  let f g () =
    Client.do_get_request
      ~uri_parameters:
        ["screen_name", screen_name;
         "cursor", (string_of_int (!cursor));
         "count", (string_of_int count)]
      ~uri:(Uri.of_string base_uri)
      ~access_token:access_token
    () >>= fun res ->
    match res with
    | Ok (header, str) -> begin
      match (Yojson.Safe.from_string str |> user_ids_of_yojson) with
      | `Ok uids -> 
        g state; (* handle states update *)
        return (Some (Ok uids))
      | `Error msg -> failwith msg 
      end
    | Error e -> return (Some (Error (process_error_exn e))) in
  Lwt_stream.from (f some_g)

before.ml

let get_follower ~access_token ~screen_name ?(count=5000) ?(wait=true) () =
  let base_uri = "https://api.twitter.com/1.1/followers/ids.json" in
  let cursor = ref (-1) in
  let f () =
    Client.do_get_request
      ~uri_parameters:
        ["screen_name", screen_name;
         "cursor", (string_of_int (!cursor));
         "count", (string_of_int count)]
      ~uri:(Uri.of_string base_uri)
      ~access_token:access_token
    () >>= fun res ->
    match res with
    | Ok (header, str) -> begin
      match (Yojson.Safe.from_string str |> user_ids_of_yojson) with
      | `Ok uids -> 
        cursor := uids.next_cursor;
        return (Some (Ok uids))
      | `Error msg -> failwith msg 
      end
    | Error e -> return (Some (Error (process_error_exn e))) in
  Lwt_stream.from f