Changes

shell-modules/default.nix

@@ -1,8 +1,14 @@
-{ nixpkgs, flake-utils, ... }:
+{
+  nixpkgs,
+  flake-utils,
+  ...
+}:
 
 let
   imports = [
+    ./shell.nix
     ./languages/python.nix
+    ./utilities/cuda.nix
   ];
 in
 {
@@ -16,15 +22,21 @@ in
           inherit system;
           config.allowUnfree = true;
         };
-        modules = [
-          attrs
-        ] ++ imports;
-        evaluated = nixpkgs.lib.evalModules { inherit modules; };
+        evaluated =
+          (nixpkgs.lib.evalModules {
+            modules = [ attrs ] ++ imports;
+            specialArgs = {
+              pkgs = pkgs;
+            };
+          }).config;
+        recUpdate = nixpkgs.lib.recursiveUpdate;
+        shell = recUpdate {
+          env = evaluated.env;
+          packages = evaluated.packages ++ (evaluated.extraPackages pkgs);
+        } evaluated.override;
       in
       {
-        devShells.default = pkgs.mkShell {
-          TEST_ENV = builtins.trace evaluated.config "HELLO";
-        };
+        devShells.default = pkgs.mkShell shell;
       }
     ));
 }

shell-modules/languages/python.nix

@@ -0,0 +1,35 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+
+with lib;
+{
+  options.python = {
+    enable = mkEnableOption "Python";
+    packages = mkOption {
+      type = types.functionTo (types.listOf types.package) // {
+        merge =
+          loc: defs: p:
+          lib.concatMap (def: (def.value p)) defs;
+      };
+      default = p: [ ];
+      description = "Python packages to install";
+    };
+    # TODO: Add option to directly read from requirements.txt, maybe with mach-nix
+  };
+
+  config = mkIf config.python.enable {
+    packages =
+      with pkgs;
+      let
+        packages = config.python.packages;
+        pythonPackage = python3.withPackages packages;
+      in
+      [
+        pythonPackage
+      ];
+  };
+}

shell-modules/shell.nix

@@ -5,7 +5,7 @@ with lib;
   options = {
     env = mkOption {
       type = types.attrsOf types.str;
-      default = [ ];
+      default = { };
     };
 
     packages = mkOption {
@@ -13,5 +13,21 @@ with lib;
       default = [ ];
       description = "Packages to install";
     };
+
+    extraPackages = mkOption {
+      type = types.functionTo (types.listOf types.package) // {
+        merge =
+          loc: defs: p:
+          lib.concatMap (def: (def.value p)) defs;
+      };
+      default = p: [ ];
+      description = "Extra packages to install";
+    };
+
+    override = mkOption {
+      type = types.attrs;
+      default = { };
+      description = "Settings in the mkShell call to override";
+    };
   };
 }

shell-modules/utilities/cuda.nix

@@ -0,0 +1,17 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+
+with lib;
+{
+  options.cuda = {
+    enable = mkEnableOption "CUDA";
+  };
+
+  config = mkIf config.cuda.enable {
+
+  };
+}