1 files changed, 41 insertions, 12 deletions
diff --git a/lib/kernel/Path.ml b/lib/kernel/Path.ml
index 803d8cf..629a527 100644
--- a/lib/kernel/Path.ml
+++ b/lib/kernel/Path.ml
@@ -3,15 +3,44 @@ type t = string list
 let this = []
 let (@/) x y = x::y
 
-let rec lookup handle = function
-  | [] -> Ok (Some handle)
-  | x::xs ->
-     let open Utilities.Result in
-     let open Protocols in
-     match Protocols.Directory.from handle with
-     | None -> Ok None
-     | Some dir ->
-        let* elem = Directory.find dir x in
-        match elem with
-        | None -> Ok None
-        | Some elem -> lookup elem xs
+let to_string path =
+  path
+  |> List.map (fun x ->
+         let str = BatString.replace ~str:x ~sub:"^" ~by:"^^" |> snd in
+         BatString.replace ~str ~sub:"/" ~by:"^/" |> snd)
+  |> BatIO.to_string (BatList.print ~first:"/" ~last:"" ~sep:"/" BatString.print)
+
+module Error = struct
+  open Concepts.Condition
+
+  let path_not_found path = condition "path-not-found" "A given path was not found under the specified object"
+                              ("path" |=| Concepts.Value.String (to_string path))
+
+  let not_a_registry path = condition "not-a-registry" "The specified path did not point to a registry"
+                              ("path" |=| Concepts.Value.String (to_string path))
+
+  let not_a_directory path = condition "not-a-directory" "The specified path did not point to a directory"
+                               ("path" |=| Concepts.Value.String (to_string path))
+end
+
+let lookup handle path =
+  let rec walk handle = function
+    | [] -> Ok handle
+    | x::xs ->
+       let open Utilities.Result in
+       let open Protocols in
+       match Directory.from handle with
+       | None -> Error (Error.path_not_found path)
+       | Some dir ->
+          let* elem = Directory.find dir x in
+          match elem with
+          | None -> Error (Error.not_a_directory path)
+          | Some elem -> walk elem xs
+  in
+  walk handle path
+
+let update handle path key reference value =
+  let open Utilities.Result in
+  let* handle = lookup handle path in
+  let* registry = Protocols.Registry.from handle |> Option.to_result ~none:(Error.not_a_registry path) in
+  Protocols.Registry.update registry key reference value