lib.types: chore use consistent payload form (#363565)

lib/types.nix

@@ -475,9 +475,10 @@ rec {
       check = isString;
       merge = loc: defs: concatStringsSep sep (getValues defs);
       functor = (defaultFunctor name) // {
-        payload = sep;
-        binOp = sepLhs: sepRhs:
-          if sepLhs == sepRhs then sepLhs
+        payload = { inherit sep; };
+        type = payload: types.separatedString payload.sep;
+        binOp = lhs: rhs:
+          if lhs.sep == rhs.sep then { inherit (lhs) sep; }
           else null;
       };
     };
@@ -1024,7 +1025,11 @@ rec {
           else "conjunction";
         check = flip elem values;
         merge = mergeEqualOption;
-        functor = (defaultFunctor name) // { payload = values; binOp = a: b: unique (a ++ b); };
+        functor = (defaultFunctor name) // {
+          payload = { inherit values; };
+          type = payload: types.enum payload.values;
+          binOp = a: b: { values = unique (a.values ++ b.values); };
+        };
       };
 
     # Either value of type `t1` or `t2`.

nixos/doc/manual/redirects.json

@@ -1844,6 +1844,12 @@
   "sec-release-25.05-notable-changes": [
     "release-notes.html#sec-release-25.05-notable-changes"
   ],
+  "sec-release-25.05-lib": [
+    "release-notes.html#sec-release-25.05-lib"
+  ],
+  "sec-release-25.05-lib-breaking": [
+    "release-notes.html#sec-release-25.05-lib-breaking"
+  ],
   "sec-release-24.11": [
     "release-notes.html#sec-release-24.11"
   ],

nixos/doc/manual/release-notes/rl-2505.section.md

@@ -118,3 +118,11 @@
 - `bind.cacheNetworks` now only controls access for recursive queries, where it previously controlled access for all queries.
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
+
+## Nixpkgs Library {#sec-release-25.05-lib}
+
+### Breaking changes {#sec-release-25.05-lib-breaking}
+
+- Structure of the `functor` of some types has changed. `functor` is an implementation detail and should not be relied upon. If you did rely on it let us know in this [PR](https://github.com/NixOS/nixpkgs/pull/363565).
+  - [`lib.types.enum`](https://nixos.org/manual/nixos/unstable/#sec-option-types-basic): Previously the `functor.payload` was the list of enum values directly. Now it is an attribute set containing the values in the `values` attribute.
+  - [`lib.types.separatedString`](https://nixos.org/manual/nixos/unstable/#sec-option-types-string): Previously the `functor.payload` was the seperator directly. Now it is an attribute set containing the seperator in the `sep` attribute.