add nixd support

flake.nix

@@ -9,6 +9,9 @@
     neovim-nightly-overlay.url = "github:nix-community/neovim-nightly-overlay";
     neovim-nightly-overlay.inputs.nixpkgs.follows = "nixpkgs";
 
+    # nix lsp support
+    nixd.url = github:nix-community/nixd;
+
     # Nix module docs generator
     nmd.url = github:gvolpe/nmd;
     #nmd.url = git+file:///home/gvolpe/workspace/nmd;
@@ -331,6 +334,7 @@
               "flake-utils"
               "neovim-nightly-flake"
               "nmd"
+              "nixd"
               "ts-build"
               "tree-sitter-scala"
               "tree-sitter-typescript"
@@ -369,10 +373,14 @@
           neovim-nightly = inputs.neovim-nightly-overlay.packages.${system}.neovim;
         };
 
+        nixdOverlay = f: p: {
+          inherit (inputs.nixd.packages.${system}) nixd;
+        };
+
         pkgs = import nixpkgs {
           inherit system;
           config = { allowUnfree = true; };
-          overlays = [ libOverlay pluginOverlay metalsOverlay neovimOverlay nmdOverlay tsOverlay ];
+          overlays = [ libOverlay pluginOverlay metalsOverlay neovimOverlay nmdOverlay nixdOverlay tsOverlay ];
         };
 
         default-ide = pkgs.callPackage ./lib/ide.nix {

modules/lsp/lsp.nix

@@ -15,9 +15,9 @@ in
     nix = {
       enable = mkEnableOption "Nix LSP";
       type = mkOption {
-        type = types.enum [ "nil" "rnix-lsp" ];
-        default = "rnix-lsp";
-        description = "Whether to use `nil` or `rnix-lsp`";
+        type = types.enum [ "nixd" "nil" "rnix-lsp" ];
+        default = "nil";
+        description = "Whether to use `nixd`, `nil` or `rnix-lsp`";
       };
     };
 
@@ -277,6 +277,17 @@ in
         }
       ''}
 
+      ${writeIf (cfg.nix.enable && cfg.nix.type == "nixd") ''
+        -- Nix config
+        lspconfig.nixd.setup{
+          capabilities = capabilities;
+          on_attach = function(client, bufnr)
+            attach_keymaps(client, bufnr)
+          end,
+          cmd = {"${pkgs.nixd}/bin/nixd"}
+        }
+      ''}
+
       ${writeIf (cfg.nix.enable && cfg.nix.type == "nil") ''
         -- Nix config
         lspconfig.nil_ls.setup{