constraint system from decker

2 files changed, 18 insertions, 2 deletions

diff --git a/lib/kernel/Path.ml b/lib/kernel/Path.ml
index 629a527..5e77c30 100644
--- a/lib/kernel/Path.ml
+++ b/lib/kernel/Path.ml
@@ -1,6 +1,9 @@
 type t = string list
 
 let this = []
+let to_list path = path
+let of_list names = names
+let equal = List.equal String.equal
 let (@/) x y = x::y
 
 let to_string path =
@@ -30,11 +33,11 @@ let lookup handle path =
        let open Utilities.Result in
        let open Protocols in
        match Directory.from handle with
-       | None -> Error (Error.path_not_found path)
+       | None -> Error (Error.not_a_directory path)
        | Some dir ->
           let* elem = Directory.find dir x in
           match elem with
-          | None -> Error (Error.not_a_directory path)
+          | None -> Error (Error.path_not_found path)
           | Some elem -> walk elem xs
   in
   walk handle path
diff --git a/lib/kernel/Path.mli b/lib/kernel/Path.mli
index 6a74350..f9f4cd0 100644
--- a/lib/kernel/Path.mli
+++ b/lib/kernel/Path.mli
@@ -3,6 +3,19 @@ type t
 val this : t
 val (@/) : string -> t -> t
 
+(** the names a path is made of, in the order it walks them *)
+val to_list : t -> string list
+
+(** a path from the names it walks, the inverse of [to_list] *)
+val of_list : string list -> t
+
+(** do two paths walk the same names *)
+val equal : t -> t -> bool
+
+(** a path as a single name, with the separator escaped where a
+    component contains it *)
+val to_string : t -> string
+
 val lookup : Protocols.Handle.t -> t -> (Protocols.Handle.t, Concepts.Condition.condition) result
 
 val update : Protocols.Handle.t -> t -> string -> Protocols.Handle.t option -> Protocols.Handle.t option -> (bool, Concepts.Condition.condition) result