fix: post rebase: 'e type param is fixed to 'value Error.t

src/decode.ml

@@ -292,7 +292,7 @@ module Make (Decodeable : Decodeable) :
       ; map : value U.String_map.t
       }
 
-    type 'a obj = (t, 'a * t, value Error.t) Decoder.t
+    type 'a obj = (t, 'a * t) Decoder.t
 
     let succeed x t = Ok (x, t)
 
@@ -338,7 +338,11 @@ module Make (Decodeable : Decodeable) :
       | Some value ->
           let m = U.String_map.remove key t.map in
           let t = { t with map = m } in
-          (match v_dec value with Ok x -> Ok (Some x, t) | Error e -> Error e)
+          ( match v_dec value with
+          | Ok x ->
+              Ok (Some x, t)
+          | Error e ->
+              Error (Error.map_context (fun context -> { t with context }) e) )
 
 
     let field key v_dec : 'a obj =
@@ -350,7 +354,7 @@ module Make (Decodeable : Decodeable) :
           Error
             (Error.make
                (Printf.sprintf "Expected an object with an attribute %S" key)
-               ~context:t.context )
+               ~context:t )
       | Error e ->
           Error e
 
@@ -366,7 +370,7 @@ module Make (Decodeable : Decodeable) :
                (Printf.sprintf
                   "Expected an empty object, but have unconsumed field %S"
                   k )
-               ~context:t.context )
+               ~context:t )
 
 
     let run : 'a obj -> 'a decoder =
@@ -375,7 +379,9 @@ module Make (Decodeable : Decodeable) :
       | Ok l ->
           let map = U.String_map.of_list l in
           let t = { context; map } in
-          dec t |> U.My_result.map (fun (x, _) -> x)
+          dec t
+          |> U.My_result.map (fun (x, _) -> x)
+          |> U.My_result.map_err (Error.map_context (fun t -> t.context))
       | Error e ->
           Error e
   end

src/error.ml

@@ -1,3 +1,5 @@
+module U = Decoders_util
+
 type 'a t =
   | E of
       { msg : string
@@ -25,7 +27,7 @@ let rec pp pp_context fmt =
       fprintf fmt "@[<2>%s:@ %a@]" msg (pp pp_context) e
   | Group es ->
       let max_errors = 5 in
-      let es_trunc = Decoders_util.My_list.take max_errors es in
+      let es_trunc = U.My_list.take max_errors es in
       let not_shown = List.length es - max_errors in
       fprintf
         fmt
@@ -38,3 +40,11 @@ let rec pp pp_context fmt =
 
 
 let map_tag f = function Tag (s, e) -> Tag (f s, e) | e -> e
+
+let rec map_context f = function
+  | E { msg; context } ->
+      E { msg; context = U.My_opt.map f context }
+  | Tag (s, e) ->
+      Tag (s, map_context f e)
+  | Group es ->
+      Group (U.My_list.map (map_context f) es)

src/error.mli

@@ -12,3 +12,5 @@ val tag_group : string -> 'a t list -> 'a t
 val pp : (Format.formatter -> 'a -> unit) -> Format.formatter -> 'a t -> unit
 
 val map_tag : (string -> string) -> 'a t -> 'a t
+
+val map_context : ('a -> 'b) -> 'a t -> 'b t