Add ppx_deriving to depends

dune-project

@@ -24,6 +24,7 @@
    (>= 4.14))
   dune
   yojson
+  ppx_deriving
   ppx_yojson_conv
   (alcotest :with-test))
  (tags (nats)))

examples/natsbyexample/dune

@@ -1,5 +1,5 @@
 (executables
- (names publish_subscribe)
+ (names publish_subscribe request_reply)
  (libraries nats-client-lwt lwt)
  (preprocess
   (pps lwt_ppx)))

examples/natsbyexample/request_reply.ml

@@ -0,0 +1,19 @@
+let main =
+  Lwt_switch.with_switch @@ fun switch ->
+  let%lwt client =
+    Nats_client_lwt.connect ~switch ~settings:[ `Echo ]
+      (Uri.of_string "nats://127.0.0.1:4222")
+  in
+
+  let%lwt requests = Nats_client_lwt.sub client ~subject:"greet.*" () in
+
+  Nats_client_lwt.Subscription.handle requests (fun request ->
+      match request.reply_to with
+      | None -> Lwt.return_unit
+      | Some reply ->
+          Printf.sprintf "hello, %s" request.subject
+          |> Nats_client_lwt.pub client ~subject:reply);
+
+  Lwt.return_unit
+
+let () = Lwt_main.run main

nats-client.opam

@@ -13,6 +13,7 @@ depends: [
   "ocaml" {>= "4.14"}
   "dune" {>= "3.16"}
   "yojson"
+  "ppx_deriving"
   "ppx_yojson_conv"
   "alcotest" {with-test}
   "odoc" {with-doc}