From 7d718405a6c3b02745201ebad02002936298fc82 Mon Sep 17 00:00:00 2001
From: Thomas Leonard <talex5@gmail.com>
Date: Tue, 21 May 2024 11:18:23 +0100
Subject: [PATCH] Add examples/fs showing how to walk a directory tree

---
 examples/fs/dune    |  3 +++
 examples/fs/main.ml | 21 +++++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 examples/fs/dune
 create mode 100644 examples/fs/main.ml

diff --git a/examples/fs/dune b/examples/fs/dune
new file mode 100644
index 000000000..fb95515c7
--- /dev/null
+++ b/examples/fs/dune
@@ -0,0 +1,3 @@
+(executable
+  (name main)
+  (libraries eio_main))
diff --git a/examples/fs/main.ml b/examples/fs/main.ml
new file mode 100644
index 000000000..d91e29d89
--- /dev/null
+++ b/examples/fs/main.ml
@@ -0,0 +1,21 @@
+(* Walks the directory tree rooted at the current directory,
+   displaying all directory names (skipping hidden directories and `_build`). *)
+
+open Eio.Std
+
+let ( / ) = Eio.Path.( / )
+
+let rec scan t =
+  match Eio.Path.kind ~follow:false t with
+  | `Directory ->
+    traceln "Visiting %a" Eio.Path.pp t;
+    Eio.Path.read_dir t |> List.iter (function
+      | "_build" -> ()
+      | item when String.starts_with ~prefix:"." item -> ()
+      | item -> scan (t / item)
+    )
+  | _ -> ()
+
+let () =
+  Eio_main.run @@ fun env ->
+  scan (Eio.Stdenv.cwd env)