Working on modularizing stuff, again

modules/develop/rust.nix

@@ -0,0 +1,36 @@
+{ config, options, lib, pkgs, ... }:
+let
+  inherit (lib.attrsets) attrValues;
+  inherit (lib.modules) mkIf mkMerge;
+  inherit (lib.meta) getExe;
+in
+{
+  options.modules.develop.rust = let
+    inherit (lib.options) mkEnableOption;
+  in {
+    enable = mkEnableOption "Rust developmnt";
+  };
+
+  config = mkMerge [
+    (mkIf config.modules.develop.rust.enable (
+      nixpkgs.overlays = [ inputs.rust.overlays.default ];
+
+      user.packages = attrValues {
+        rust-package = pkgs.rust-bin.nightly.latest.default;
+        inherit (pkgs) rust-analyser rust-script;
+      };
+
+      environment.shellAlliases = {
+        rs = "rustc";
+        ca = "cargo";
+      };
+    ))
+
+    (mkIf config.modules.develop.cdg.enable {
+      env = {
+        CARGO_HOME = "$XDG_DATA_HOME/cargo";
+        PATH = [ "$CARGO_HOME/bin" ];
+      };
+    })
+  ];
+}