flake: move system builders to lib/builders.nix

flake.nix

@@ -37,33 +37,12 @@
 
   outputs =
     { self, nixpkgs, ... }@inputs:
+    let
+      builders = import ./lib/builders.nix inputs;
+    in
     {
       nixosConfigurations =
-        let
+        builders.compileSystems
-          lib = import ./lib nixpkgs.lib;
-
-          toPartialNixosConfig =
-            { hostname, system }:
-            {
-              name = hostname;
-              value = nixpkgs.lib.nixosSystem {
-                inherit system;
-                specialArgs = { inherit inputs; };
-                modules = [
-                  ./hosts/${hostname}/hardware-configuration.nix
-                  ./hosts/${hostname}/configuration.nix
-                  inputs.home-manager.nixosModules.default
-                ];
-              };
-            };
-          compileSystems =
-            systems:
-            lib.right
-              builtins.listToAttrs
-              (map toPartialNixosConfig)
-              systems;
-        in
-        compileSystems
           [
             {
               hostname = "snowhawk";

lib/builders.nix

@@ -0,0 +1,27 @@
+{ nixpkgs, ... }@inputs:
+
+let
+  lib = import ../lib nixpkgs;
+in
+rec {
+  toPartialNixosConfig =
+    { hostname, system }:
+    {
+      name = hostname;
+      value = nixpkgs.lib.nixosSystem {
+        inherit system;
+        specialArgs = { inherit inputs; };
+        modules = [
+          ../hosts/${hostname}/hardware-configuration.nix
+          ../hosts/${hostname}/configuration.nix
+          inputs.home-manager.nixosModules.default
+        ];
+      };
+    };
+  compileSystems =
+    systems:
+    lib.right
+      builtins.listToAttrs
+      (map toPartialNixosConfig)
+      systems;
+}