aantron · Willenbrink · Jan 19, 2022 · Jan 18, 2022 · Apr 3, 2023 · Apr 3, 2023
diff --git a/Makefile b/Makefile
@@ -1,4 +1,8 @@
 .PHONY : build
+
+default:
+	@dune build
+
 build :
 	@dune build -p dream-pure,dream-httpaf,dream --no-print-directory @install
 

diff --git a/dream-httpaf.opam b/dream-httpaf.opam
@@ -17,9 +17,7 @@ depends: [
   "dune" {>= "2.7.0"}  # --instrument-with.
   "lwt"
   "lwt_ppx" {>= "1.2.2"}
-  "lwt_ssl"
   "ocaml" {>= "4.08.0"}
-  "ssl" {>= "0.5.8"}  # Ssl.get_negotiated_alpn_protocol.
 
   # Currently vendored.
   # "gluten"

diff --git a/dream-pure.opam b/dream-pure.opam
@@ -22,6 +22,7 @@ depends: [
   "ocaml" {>= "4.08.0"}
   "ptime" {>= "0.8.1"}  # Ptime.weekday.
   "uri" {>= "4.2.0"}
+  "eio" {>= "0.2"}
 
   # Testing, development.
   "alcotest" {with-test}

diff --git a/dream.opam b/dream.opam
@@ -62,7 +62,6 @@ depends: [
   "graphql-lwt"
   "lwt"
   "lwt_ppx" {>= "1.2.2"}
-  "lwt_ssl"
   "logs" {>= "0.5.0"}
   "magic-mime"
   "mirage-clock" {>= "3.0.0"}  # now_d_ps : unit -> int * int64.
@@ -73,9 +72,10 @@ depends: [
   "multipart_form-lwt"
   "ocaml" {>= "4.08.0"}
   "ptime" {>= "0.8.1"}  # Ptime.v.
-  "ssl" {>= "0.5.8"}  # Ssl.get_negotiated_alpn_protocol.
   "uri" {>= "4.2.0"}
   "yojson"  # ...
+  "eio_main" {>= "0.2"}
+  "lwt_eio" {>= "0.1"}
 
   # Testing, development.
   "alcotest" {with-test}

diff --git a/example/1-hello/README.md b/example/1-hello/README.md
@@ -6,8 +6,10 @@ This project is so simple that it doesn't even log requests!
 
 ```ocaml
 let () =
-  Dream.run (fun _ ->
-    Dream.html "Good morning, world!")
+  Eio_main.run (fun env ->
+    Dream.run env (fun _ ->
+      Dream.html "Good morning, world!")
+  )
 ```
 
 <br>
@@ -39,6 +41,11 @@ name of the `.ml` file, but with `.ml` changed to `.exe`.
 
 <br>
 
+A Dream server runs in an [Eio](https://github.com/ocaml-multicore/eio) event loop,
+which is created by `Eio_main.run`.
+
+<br>
+
 **Next steps:**
 
 - The next example, [**`2-middleware`**](../2-middleware#files), adds a logger

diff --git a/example/1-hello/hello.ml b/example/1-hello/hello.ml
@@ -1,3 +1,5 @@
 let () =
-  Dream.run (fun _ ->
-    Dream.html "Good morning, world!")
+  Eio_main.run (fun env ->
+    Dream.run env (fun _ ->
+      Dream.html "Good morning, world!")
+  )
diff --git a/example/2-middleware/README.md b/example/2-middleware/README.md
@@ -9,9 +9,10 @@ middlewares, the [*logger*](https://aantron.github.io/dream/#val-logger):
 
 ```ocaml
 let () =
-  Dream.run
-    (Dream.logger (fun _ ->
-      Dream.html "Good morning, world!"))
+  Eio_main.run (fun env ->
+    Dream.run env
+      (Dream.logger (fun _ ->
+        Dream.html "Good morning, world!")))
 ```
 
 <br>
@@ -25,7 +26,8 @@ in this example looks like this:
 
 ```ocaml
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ fun _ -> Dream.html "Good morning, world!"
 ```

diff --git a/example/2-middleware/middleware.ml b/example/2-middleware/middleware.ml
@@ -1,4 +1,5 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ fun _ -> Dream.html "Good morning, world!"
diff --git a/example/3-router/router.ml b/example/3-router/router.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 

diff --git a/example/4-counter/counter.ml b/example/4-counter/counter.ml
@@ -5,7 +5,8 @@ let count_requests inner_handler request =
   inner_handler request
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ count_requests
   @@ Dream.router [

diff --git a/example/5-promise/README.md b/example/5-promise/README.md
@@ -1,29 +1,30 @@
 # `5-promise`
 
+(note this example is now badly named, as it doesn't use any promises)
+
 <br>
 
 [**`4-counter`**](../4-counter#files) was limited to counting requests *before*
-passing them on to the rest of the app. With the promise library
-[Lwt](https://github.com/ocsigen/lwt), we can await responses, and do something
-*after*. In this example, we separately count requests that were handled
-successfully, and those that caused an exception:
+passing them on to the rest of the app. We can also await responses, and do
+something *after*. In this example, we separately count requests that were
+handled successfully, and those that caused an exception:
 
 ```ocaml
 let successful = ref 0
 let failed = ref 0
 
 let count_requests inner_handler request =
-  try%lwt
-    let%lwt response = inner_handler request in
+  try
+    let response = inner_handler request in
     successful := !successful + 1;
-    Lwt.return response
-
+    response
   with exn ->
     failed := !failed + 1;
     raise exn
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ count_requests
   @@ Dream.router [
@@ -48,49 +49,13 @@ Try it in the [playground](http://dream.as/5-promise).
 
 <br>
 
-As you can see, the
-[core constructs](https://ocsigen.org/lwt/latest/api/Ppx_lwt) of Lwt are:
-
-- `let%lwt` to await the result of a promise.
-- `try%lwt` to catch both exceptions and rejections. Lwt promises can only be
-  rejected with exceptions, of OCaml type `exn`.
-- `Lwt.return` to resolve a promise.
-
-Besides these, Lwt has a lot of [convenience
-functions](https://ocsigen.org/lwt/latest/api/Lwt), and an [asychronous
-I/O library](https://ocsigen.org/lwt/latest/api/Lwt_unix).
+As you can see, we use `try` to catch both exceptions and rejections.
 
 <!-- TODO Link to read_file and write_file helpers. -->
 <!-- TODO Link to Lwt_unix, Lwt_io, Lwt. -->
 
 <br>
 
-To use `let%lwt`, we need to modify our
-[`dune`](https://github.com/aantron/dream/blob/master/example/5-promise/dune)
-file a bit to include `lwt_ppx`:
-
-<pre><code>(executable
- (name promise)
- (libraries dream)
- <b>(preprocess (pps lwt_ppx)))</b>
-</code></pre>
-
-There are other ways to write *await* and *catch* in Lwt that don't require
-`lwt_ppx`, but `lwt_ppx` is presently the best for preserving nice stack traces.
-For example, `let%lwt` is equivalent to...
-
-- [`Lwt.bind`](https://github.com/ocsigen/lwt/blob/c5f895e35a38df2d06f19fd23bf553129b9e95b3/src/core/lwt.mli#L475),
-  which is almost never used directly.
-- [`>>=`](https://github.com/ocsigen/lwt/blob/c5f895e35a38df2d06f19fd23bf553129b9e95b3/src/core/lwt.mli#L1395)
-  from module `Lwt.Infix`.
-- [`let*`](https://github.com/ocsigen/lwt/blob/c5f895e35a38df2d06f19fd23bf553129b9e95b3/src/core/lwt.mli#L1511)
-  from module `Lwt.Syntax`, which is showcased in Lwt's
-  [README](https://github.com/ocsigen/lwt#readme).
-
-We will stick to `let%lwt` in the examples and keep things tidy.
-
-<br>
-
 **Next steps:**
 
 - [**`6-echo`**](../6-echo#files) uses Dream and Lwt to read a request body.

diff --git a/example/5-promise/dune b/example/5-promise/dune
@@ -1,6 +1,5 @@
 (executable
  (name promise)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (data_only_dirs _esy esy.lock lib node_modules)
diff --git a/example/5-promise/promise.ml b/example/5-promise/promise.ml
@@ -2,17 +2,17 @@ let successful = ref 0
 let failed = ref 0
 
 let count_requests inner_handler request =
-  try%lwt
-    let%lwt response = inner_handler request in
+  try
+    let response = inner_handler request in
     successful := !successful + 1;
-    Lwt.return response
-
+    response
   with exn ->
     failed := !failed + 1;
     raise exn
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ count_requests
   @@ Dream.router [

diff --git a/example/6-echo/dune b/example/6-echo/dune
@@ -1,6 +1,5 @@
 (executable
  (name echo)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (data_only_dirs _esy esy.lock lib node_modules)
diff --git a/example/6-echo/echo.ml b/example/6-echo/echo.ml
@@ -1,10 +1,11 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
     Dream.post "/echo" (fun request ->
-      let%lwt body = Dream.body request in
+      let body = Dream.body request in
       Dream.respond
         ~headers:["Content-Type", "application/octet-stream"]
         body);

diff --git a/example/7-template/README.md b/example/7-template/README.md
@@ -42,8 +42,7 @@ file to run the template preprocessor:
 
 <pre><code>(executable
  (name template)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 <b>(rule
  (targets template.ml)

diff --git a/example/7-template/template.eml.ml b/example/7-template/template.eml.ml
@@ -6,7 +6,8 @@ let render param =
   </html>
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 

diff --git a/example/8-debug/debug.ml b/example/8-debug/debug.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run ~error_handler:Dream.debug_error_handler
+  Eio_main.run @@ fun env ->
+  Dream.run ~error_handler:Dream.debug_error_handler env
   @@ Dream.logger
   @@ Dream.router [
 

diff --git a/example/9-error/error.eml.ml b/example/9-error/error.eml.ml
@@ -12,9 +12,10 @@ let my_error_template _error debug_info suggested_response =
     </body>
     </html>
   end;
-  Lwt.return suggested_response
+  suggested_response
 
 let () =
-  Dream.run ~error_handler:(Dream.error_template my_error_template)
+  Eio_main.run @@ fun env ->
+  Dream.run ~error_handler:(Dream.error_template my_error_template) env
   @@ Dream.logger
   @@ Dream.not_found
diff --git a/example/a-log/log.ml b/example/a-log/log.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 

diff --git a/example/b-session/dune b/example/b-session/dune
@@ -1,6 +1,5 @@
 (executable
  (name session)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (data_only_dirs _esy esy.lock lib node_modules)
diff --git a/example/b-session/session.ml b/example/b-session/session.ml
@@ -1,13 +1,14 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.memory_sessions
   @@ fun request ->
 
     match Dream.session_field request "user" with
     | None ->
-      let%lwt () = Dream.invalidate_session request in
-      let%lwt () = Dream.set_session_field request "user" "alice" in
+      Dream.invalidate_session request;
+      Dream.set_session_field request "user" "alice";
       Dream.html "You weren't logged in; but now you are!"
 
     | Some username ->

diff --git a/example/c-cookie/cookie.ml b/example/c-cookie/cookie.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.set_secret "foo"
   @@ Dream.logger
   @@ fun request ->
@@ -13,4 +14,4 @@ let () =
       let response = Dream.response "Set language preference; come again!" in
       Dream.add_header response "Content-Type" Dream.text_html;
       Dream.set_cookie response request "ui.language" "ut-OP";
-      Lwt.return response
+      response
diff --git a/example/d-form/dune b/example/d-form/dune
@@ -1,7 +1,6 @@
 (executable
  (name form)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (rule
  (targets form.ml)

diff --git a/example/d-form/form.eml.ml b/example/d-form/form.eml.ml
@@ -17,7 +17,8 @@ let show_form ?message request =
   </html>
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.memory_sessions
   @@ Dream.router [
@@ -28,7 +29,7 @@ let () =
 
     Dream.post "/"
       (fun request ->
-        match%lwt Dream.form request with
+        match Dream.form request with
         | `Ok ["message", message] ->
           Dream.html (show_form ~message request)
         | _ ->

diff --git a/example/e-json/README.md b/example/e-json/README.md
@@ -43,7 +43,7 @@ To get this working, we have to add `ppx_yojson_conv` to our
 <pre><code>(executable
  (name json)
  (libraries dream)
- <b>(preprocess (pps lwt_ppx ppx_yojson_conv)))</b>
+ <b>(preprocess (pps ppx_yojson_conv)))</b>
 </code></pre>
 
 and to