Use nested attrsets for nested sections

example/home.nix

@@ -65,8 +65,7 @@
     #
     configFile = {
       "baloofilerc"."Basic Settings"."Indexing-Enabled" = false;
-      # If a group name has dots you need to escape them
-      "kwinrc"."org\\.kde\\.kdecoration2"."ButtonsOnLeft" = "SF";
+      "kwinrc"."org.kde.kdecoration2"."ButtonsOnLeft" = "SF";
     };
   };
 }

modules/files.nix

@@ -16,31 +16,38 @@ let
     (prependPath config.xdg.configHome plasmaCfg.configFile) //
     (prependPath config.xdg.dataHome plasmaCfg.dataFile);
 
-  ##############################################################################
-  # A module for storing settings.
-  settingType = { name, ... }: {
-    freeformType = with lib.types;
-      attrsOf (nullOr (oneOf [ bool float int str ]));
+  # Flatten nested sections
+  flatten = config: builtins.listToAttrs (lib.flatten (lib.mapAttrsToList
+    (n: v:
+      let
+        keySet = lib.filterAttrs (n: v: !builtins.isAttrs v) v;
+        sectionSet = flatten (lib.filterAttrs (n: v: builtins.isAttrs v) v);
+      in
+      lib.optionals (keySet != { }) [{
+        name = n;
+        value = keySet;
+      }] ++ lib.mapAttrsToList
+        (group: v: {
+          name = "${n}][${group}";
+          value = v;
+        })
+        sectionSet)
+    config));
 
-    options = {
-      configGroupNesting = lib.mkOption {
-        type = lib.types.nonEmptyListOf lib.types.str;
-        # We allow escaping periods using \\.
-        default = (map
-          (e: builtins.replaceStrings [ "\\u002E" ] [ "." ] e)
-          (lib.splitString "."
-            (builtins.replaceStrings [ "\\." ] [ "\\u002E" ] name)
-          )
-        );
-        description = "Group name, and sub-group names.";
-      };
-    };
-  };
+  flatCfg = builtins.mapAttrs (file: flatten) cfg;
+
+  ##############################################################################
+  # A type for storing settings.
+  settingsFileType = with lib.types; let
+    valueType = attrsOf (nullOr (oneOf [ bool float int str valueType ])) //
+      { description = "Plasma settings"; };
+  in
+  attrsOf (attrsOf (valueType));
 
   ##############################################################################
   # Generate a script that will use write_config.py to update all
   # settings.
-  script = pkgs.writeScript "plasma-config" (writeConfig cfg);
+  script = pkgs.writeScript "plasma-config" (writeConfig flatCfg);
 
   ##############################################################################
   # Generate a script that will remove all the current config files.
@@ -98,7 +105,7 @@ in
 {
   options.programs.plasma = {
     file = lib.mkOption {
-      type = with lib.types; attrsOf (attrsOf (submodule settingType));
+      type = settingsFileType;
       default = { };
       description = ''
         An attribute set where the keys are file names (relative to
@@ -107,7 +114,7 @@ in
       '';
     };
     configFile = lib.mkOption {
-      type = with lib.types; attrsOf (attrsOf (submodule settingType));
+      type = settingsFileType;
       default = { };
       description = ''
         An attribute set where the keys are file names (relative to
@@ -116,7 +123,7 @@ in
       '';
     };
     dataFile = lib.mkOption {
-      type = with lib.types; attrsOf (attrsOf (submodule settingType));
+      type = settingsFileType;
       default = { };
       description = ''
         An attribute set where the keys are file names (relative to

modules/kwin.nix

@@ -74,7 +74,7 @@ in
 
   config = mkIf cfg.enable {
     # Titlebar buttons
-    programs.plasma.configFile."kwinrc"."org\\.kde\\.kdecoration2" = mkMerge [
+    programs.plasma.configFile."kwinrc"."org.kde.kdecoration2" = mkMerge [
       (
         mkIf (cfg.kwin.titlebarButtons.left != null) {
           "ButtonsOnLeft" = strings.concatStrings (getShortNames cfg.kwin.titlebarButtons.left);

modules/shortcuts.nix

@@ -25,12 +25,7 @@ let
 
   shortcutsToSettings = groups:
     lib.mapAttrs
-      (group: attrs:
-        (lib.mapAttrs shortcutToNameValuePair attrs) // {
-          # Some shortcut groups have a dot in their name so we
-          # explicitly set the group nesting to only one level deep:
-          configGroupNesting = [ group ];
-        })
+      (group: attrs: (lib.mapAttrs shortcutToNameValuePair attrs))
       groups;
 in
 {

script/rc2nix.rb

@@ -144,8 +144,8 @@ def parse
     ############################################################################
     def parse_group(line)
       line.gsub(/\s*\[([^\]]+)\]\s*/) do |match|
-        $1 + "."
-      end.sub(/\.$/, '')
+        $1 + "\".\""
+      end.sub(/\"."$/, '')
     end
   end
 

script/write_config.py

@@ -105,13 +105,8 @@ def key_value_to_line(key: str, value: str) -> str:
 def write_config_single(filepath: str, items: Dict):
     config = KConfParser(filepath)
 
-    for entry in items.values():
-        group = f"{']['.join(entry['configGroupNesting'])}"
-
+    for group, entry in items.items():
         for key, value in entry.items():
-            if key == "configGroupNesting":
-                continue
-
             # If the nix expression is null, resulting in the value None here,
             # we remove the key/option (and the group/section if it is empty
             # after removal).