lib: restructure folder structure

To easily support channels and flake.

default.nix

@@ -1,8 +1,7 @@
 { pkgs ? import <nixpkgs> { } }:
 
 let
-  lib' = pkgs.lib.extend (final: prev:
+  lib' = pkgs.lib.extend (import ./lib/extras/extend-lib.nix);
-    import ./lib { lib = prev; } // import ./lib/private.nix { lib = final; });
 in
 {
   lib = import ./lib { lib = pkgs.lib; };

flake.nix

@@ -87,7 +87,7 @@
       users = lib'.importTOML ./users.toml;
 
       # A set of image-related utilities for the flake outputs.
-      inherit (import ./lib/images.nix { inherit inputs; lib = lib'; }) mkHost mkHome mkImage listImagesWithSystems;
+      inherit (import ./lib/extras/images.nix { inherit inputs; lib = lib'; }) mkHost mkHome mkImage listImagesWithSystems;
 
       # The order here is important(?).
       overlays = [

lib/extras/extend-lib.nix

@@ -0,0 +1,16 @@
+# A lambda suitable to be used for `pkgs.lib.extend`.
+self: super: let
+  publicLib = import ../. { lib = super; };
+in
+{
+  inherit (publicLib) filesToAttr countAttrs getSecrets
+    attachSopsPathPrefix;
+
+  # Until I figure out how to properly add them only for their respective
+  # environment, this is the working solution for now. Not really perfect
+  # since we use one nixpkgs instance for each configuration (home-manager or
+  # otherwise).
+  private = publicLib
+            // import ../private.nix { lib = self; }
+            // import ../home-manager.nix { lib = self; };
+}

lib/extras/images.nix

@@ -4,15 +4,7 @@
 
 let
   # A function that generates a lambda suitable for `lib.extend`.
-  extendLib = self: super: let
+  extendLib = import ./extend-lib.nix;
-    publicLib = import ./. { lib = super; };
-  in
-  {
-    inherit (publicLib) filesToAttr countAttrs getSecrets
-      attachSopsPathPrefix;
-    private = publicLib
-              // import ./private.nix { lib = self; };
-  };
 in
 {
   # A thin wrapper around the NixOS configuration function.