node inheritance + group parsing

nix/snow/flake/lib.nix

@@ -1,49 +0,0 @@
-{
-  lib,
-  revInfo ? "",
-}: let
-  inherit
-    (lib)
-    mkOption
-    types
-    ;
-
-  # A best effort, lenient estimate. Please use a recent nixpkgs lib if you
-  # override it at all.
-  minVersion = "23.05pre-git";
-
-  isNixpkgsValidVersion =
-    (builtins.compareVersions lib.version minVersion < 0)
-    # XXX: TODO: make this message snow specific
-    || abort ''
-      The nixpkgs-lib dependency of flake-parts was overridden but is too old.
-      The minimum supported version of nixpkgs-lib is ${minVersion},
-      but the actual version is ${lib.version}${revInfo}.
-    '';
-in
-  assert isNixpkgsValidVersion; {
-    # Helper function for defining a per-system option that
-    # gets transposed by the usual flake system logic to a
-    # top-level outputs attribute.
-    mkPerSystemFlakeOutput = {
-      name,
-      option,
-      file,
-    }: {
-      _file = file;
-
-      options = {
-        outputs.${name} = mkOption {
-          type = types.attrsWith {
-            elemType = option.type;
-            lazy = true;
-            placeholder = "system";
-          };
-          default = {};
-          description = ''
-            See {option}`perSystem.${name}` for description and examples.
-          '';
-        };
-      };
-    };
-  }