modules/telescope: add option to customize loading

modules/plugins/navigation/telescope.nix

@@ -14,32 +14,34 @@ let
     if isFunction cfg.extensions then cfg.extensions telescopeExtensions
     else cfg.extensions;
 
-  extensionOpts = { name, config, ... }: {
+  extensionOpts = { name, ... } @ sub: {
     options = with lib; with types; {
       name = mkOption {
         type = str;
         description = "Extension name";
       };
+
       package = mkPackageOption telescopeExtensions name { };
+
       settings = mkOption {
         type = attrs;
         default = { };
+        description = "Additional configuration to setup an extension";
       };
 
-      # TODO: add an option to change the way the extension is loaded.
-
-      afterTelescopeSetup = mkOption {
-        type = listOf attrs;
-        readOnly = true;
-        internal = true;
+      loadExtension = mkOption {
+        type = nullOr attrs;
+        description = "Expression to load extension";
+        defaultText = literalExpression ''require("telescope").load_extension("<name>")'';
       };
     };
 
     config = {
       name = lib.mkDefault name;
-
-      afterTelescopeSetup = with nix2lua; lib.optional (config.settings != { })
-        (pipe1 (var config.plugin.telescope-nvim.varName) (call "load_extension" config.name));
+      loadExtension = with nix2lua; lib.mkDefault (pipe1
+        (var config.plugin.telescope-nvim.varName)
+        (call "load_extension" sub.config.name)
+      );
     };
   };
 
@@ -93,7 +95,7 @@ in
               (lib.filterAttrs (k: v: v.settings != { }) extensions)
             )
           ]);
-          afterSetup = lib.flatten (map (ext: ext.afterTelescopeSetup) (attrValues extensions));
+          afterSetup = map (ext: ext.loadExtension) (attrValues extensions);
         };
       }