Fix KDL.of_flow Result type and update callers

- Properly type annotate KDL.of_flow to return (t, [> `ParseError]) result
- Handle nested Results from Eio.Buf_read.parse_exn
- Fix Manifest.read to work with new Result type
- Fix nixtamal.ml error handling for Manifest and Lockfile errors

All 17 tests pass.

3 files changed, 12 insertions, 15 deletions

diff --git a/lib/kDL.ml b/lib/kDL.ml
index a00d1ff..5f94557 100644
--- a/lib/kDL.ml
+++ b/lib/kDL.ml
@@ -5,13 +5,15 @@
 (* extend & fix casing for ocaml-kdl *)
 include Kdl
 
-let of_flow flow =
+let of_flow flow : (t, [> `ParseError of string]) result =
 	try
-		Eio.Buf_read.parse_exn
+		match Eio.Buf_read.parse_exn
 			(fun buf -> Eio.Buf_read.take_all buf |> Kdl.of_string)
 			~max_size: max_int
 			flow
-		|> Result.ok
+		with
+		| Ok doc -> Ok doc
+		| Error _ -> Error (`ParseError "KDL parse error")
 	with
 		| Kdl.Parse_error (msg, _) -> Error (`ParseError msg)
 
diff --git a/lib/manifest.ml b/lib/manifest.ml
index 7bf2997..c2c7c79 100644
--- a/lib/manifest.ml
+++ b/lib/manifest.ml
@@ -865,17 +865,14 @@ let exists () : bool =
 	Eio.Path.is_file filepath
 
 let read () =
-	let (let*) = Result.bind in
 	let working_dir = Working_directory.get () in
 	let filepath = Eio.Path.(working_dir / filename) in
 	Logs.info (fun m -> m "Reading manifest @@ %a …" Eio.Path.pp filepath);
-	let kdl_result =
-		Eio.Path.with_open_in filepath @@ fun flow ->
-		KDL.of_flow flow
-	in
-	let* kdl = kdl_result |> Result.map_error (fun (`ParseError msg) -> `Parsing [`ParseError msg]) in
-	let () = manifest := Some kdl in
-	Ok kdl
+	match Eio.Path.with_open_in filepath KDL.of_flow with
+	| Error (`ParseError msg) -> Error (`Parsing [`ParseError msg])
+	| Ok kdl ->
+		let () = manifest := Some kdl in
+		Ok kdl
 
 let make ?(version = "0.1.1") () =
 	Logs.app (fun m -> m "Making manifest file @@ version:%s" version);
diff --git a/lib/nixtamal.ml b/lib/nixtamal.ml
index a9435ab..9ef08e7 100644
--- a/lib/nixtamal.ml
+++ b/lib/nixtamal.ml
@@ -53,9 +53,7 @@ let read_manifest_and_lockfile () : (Name.Name.t list, error) result =
 			| Ok(kdl : KDL.t) ->
 				Manifest.document_to_t kdl
 				|> Result.map_error (fun err -> `Parsing err)
-			| Error(e : KDL.error) ->
-				let v_errs : KDL.Valid.err list = [`ParseError e] in
-				Error (`Parsing v_errs)
+			| Error err -> Error err
 		end
 	in
 	let* lockfile_opt =
@@ -350,7 +348,7 @@ let upgrade ?from ?(to_ = Schema.Version.current) ?(dry_run = false) () : (unit,
 			let* () =
 				match Manifest.read () with
 				| Ok _ -> Logs.info (fun m -> m "Manifest verified."); Ok ()
-				| Error e -> Error (`Manifest (`Parsing [`ParseError e]))
+				| Error e -> Error (`Manifest e)
 			in
 			let* () =
 				match Lockfile.read () with