From d44447d69c28bdd581452f5b733605192b707998 Mon Sep 17 00:00:00 2001
From: asymmetric <101816+asymmetric@users.noreply.github.com>
Date: Tue, 10 Dec 2024 13:12:36 +0100
Subject: [PATCH] example/h-sql: document Lwt.bind

---
 example/h-sql/README.md  | 7 +++++--
 example/h-sql/sql.eml.ml | 3 +--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/example/h-sql/README.md b/example/h-sql/README.md
index aab16638..9b518989 100644
--- a/example/h-sql/README.md
+++ b/example/h-sql/README.md
@@ -7,6 +7,10 @@ prepared statements using
 [Caqti](https://paurkedal.github.io/ocaml-caqti/caqti/Caqti_connect_sig/module-type-S/module-type-CONNECTION/index.html),
 a library for talking to SQL databases:
 
+> [!TIP]
+> The `let%lwt` syntax is syntactic sugar for `Lwt.bind`, so the two forms below are equivalent (a third option would be using `>>=`).
+> For more information, see [here](https://ocsigen.org/lwt/latest/api/Lwt#3_Callbacks).
+
 ```ocaml
 module type DB = Caqti_lwt.CONNECTION
 module T = Caqti_type
@@ -17,8 +21,7 @@ let list_comments =
     (T.unit ->* T.(tup2 int string))
     "SELECT id, text FROM comment" in
   fun (module Db : DB) ->
-    let%lwt comments_or_error = Db.collect_list query () in
-    Caqti_lwt.or_fail comments_or_error
+    Lwt.bind (Db.collect_list query ()) Caqti_lwt.or_fail
 
 let add_comment =
   let query =
diff --git a/example/h-sql/sql.eml.ml b/example/h-sql/sql.eml.ml
index c542c4d8..0ef7ef79 100644
--- a/example/h-sql/sql.eml.ml
+++ b/example/h-sql/sql.eml.ml
@@ -7,8 +7,7 @@ let list_comments =
     (T.unit ->* T.(t2 int string))
     "SELECT id, text FROM comment" in
   fun (module Db : DB) ->
-    let%lwt comments_or_error = Db.collect_list query () in
-    Caqti_lwt.or_fail comments_or_error
+    Lwt.bind (Db.collect_list query ()) Caqti_lwt.or_fail
 
 let add_comment =
   let query =