load packages only if installed

flake.nix

@@ -39,10 +39,8 @@
     wrappers,
     ...
   } @ inputs: let
-    mkWrapperConfig = pkgs: let
+    mkWrapperConfig = pkgs: {
-      def = pkgs.lib.mkDefault;
+      cats = {
-    in {
-      cats = pkgs.lib.mapAttrs (_: v: def v) {
         clickhouse = false;
         gitPlugins = true;
         julia = false;
@@ -55,22 +53,12 @@
       };
       settings = {
         lang_packages = {
-          python = def (with pkgs.python3Packages; [
+          python = [];
-            duckdb
+          r = [];
-            polars
+          julia = [];
-          ]);
-          r = def ((with pkgs.rpkgs.rPackages; [
-            arrow
-            broom
-            data_table
-            janitor
-            languageserver
-            styler
-          ]) ++ [ pkgs.nvimcom ]);
-          julia = def ["DataFramesMeta" "QuackIO"];
         };
       };
-      binName = def "vv";
+      binName = "vv";
     };
 
     wrapperSettings = pkgs: let
@@ -78,7 +66,7 @@
     in
       wrapper.config.wrap {
         inherit pkgs;
-        inherit (cfg) cats settings binName;
+        inherit (cfg) settings binName;
       };
 
     systems = [
@@ -135,14 +123,29 @@
     devShells = forAllSystems (
       system: let
         pkgs = mkPkgs system;
-        cfg = mkWrapperConfig pkgs;
         nvimPkg = wrapperSettings pkgs;
 
+        pythonPkgs = with pkgs.python3Packages; [
+          duckdb
+          polars
+        ];
+
+        rPkgs = (with pkgs.rpkgs.rPackages; [
+          arrow
+          broom
+          data_table
+          janitor
+          languageserver
+          styler
+        ]) ++ [ pkgs.nvimcom ];
+
+        juliaPkgs = ["DataFramesMeta" "QuackIO"];
+
         pythonPackages = let
           python_packages_fn =
             if pkgs ? basePythonPackages
-            then ps: pkgs.basePythonPackages ps ++ cfg.settings.lang_packages.python
+            then ps: pkgs.basePythonPackages ps ++ pythonPkgs
-            else _: cfg.settings.lang_packages.python;
+            else _: pythonPkgs;
         in
           with pkgs; [
             (python3.withPackages python_packages_fn)
@@ -153,7 +156,7 @@
           ];
 
         rPackages = let
-          r_packages = (pkgs.baseRPackages or []) ++ cfg.settings.lang_packages.r;
+          r_packages = (pkgs.baseRPackages or []) ++ rPkgs;
         in
           with pkgs; [
             (rWrapper.override {packages = r_packages;})
@@ -167,7 +170,7 @@
           ];
 
         juliaPackages = let
-          julia_with_packages = pkgs.julia-bin.withPackages cfg.settings.lang_packages.julia;
+          julia_with_packages = pkgs.julia-bin.withPackages juliaPkgs;
         in [julia_with_packages];
 
         markdownPackages = with pkgs; [

ftplugin/markdown.lua

@@ -1,5 +1,7 @@
 -- Add the key mappings only for Markdown files in a zk notebook.
-if require("zk.util").notebook_root(vim.fn.expand('%:p')) ~= nil then
+local nix = require("config.nix")
+if nix.get_cat("markdown", false) then
+  if require("zk.util").notebook_root(vim.fn.expand('%:p')) ~= nil then
     local map = vim.keymap.set
     -- Open the link under the caret.
     map("n", "<CR>", "<Cmd>lua vim.lsp.buf.definition()<CR>", { noremap = true, silent = false, buffer = true })
@@ -29,4 +31,5 @@ if require("zk.util").notebook_root(vim.fn.expand('%:p')) ~= nil then
     map("v", "<leader>za", ":'<,'>lua vim.lsp.buf.range_code_action()<CR>",
       { noremap = true, silent = false, buffer = true, desc = "Code actions" })
 
+  end
 end

plugin/20_startup.lua

@@ -390,6 +390,7 @@ end)
 
 -- zk
 now_if_args(function()
+  if nix.get_cat("markdown", false) then
     require("zk").setup({
       picker = "minipick",
       lsp = {
@@ -409,4 +410,5 @@ now_if_args(function()
 
       },
     })
+  end
 end)

plugin/21_datascience.lua

@@ -71,6 +71,7 @@ end)
 now(function()
   vim.treesitter.language.register("markdown", { "quarto", "rmd" })
 
+  if nix.get_cat({"r", "markdown"}, false) then
     vim.api.nvim_create_autocmd("FileType", {
       pattern = { "quarto" },
       callback = function()
@@ -87,6 +88,7 @@ now(function()
         write_to_disk = true,
       },
     })
+  end
 end)
 
 later(function()