new decoding signature

See roc-lang/roc#6587 for context.

Author: Anton-4

flake.lock

@@ -2,7 +2,7 @@
   description = "basic-webserver devShell flake";
 
   inputs = {
-    roc.url = "github:roc-lang/roc";
+    roc.url = "github:faldor20/roc/3fef8b9f82acb70c7fb8b142e886ac5dd4495fe6";
     nixpkgs.follows = "roc/nixpkgs";
 
     # rust from nixpkgs has some libc problems, this is patched in the rust-overlay
@@ -60,4 +60,4 @@
 
         formatter = pkgs.nixpkgs-fmt;
       });
-}
+}

flake.nix

@@ -91,7 +91,7 @@ envList = \decodeElem -> Decode.custom \bytes, @EnvFormat {} ->
 # TODO: we must currently annotate the arrows here so that the lambda sets are
 # exercised, and the solver can find an ambient lambda set for the
 # specialization.
-envRecord : _, (_, _ -> [Keep (Decoder _ _), Skip]), (_ -> _) -> Decoder _ _
+envRecord : _, (_, _ -> [Keep (Decoder _ _), Skip]), (_, _ -> _) -> Decoder _ _
 envRecord = \_initialState, _stepField, _finalizer -> Decode.custom \bytes, @EnvFormat {} ->
         { result: Err TooShort, rest: bytes }