Code cleanup.

config/networking.nix

@@ -1,8 +1,6 @@
 { config, ... }:
 
-let
- firewallcfg = config.machine.firewall;
-in {
+{
   networking = {
     hostName = config.machine.hostName;
   };

config/users.nix

@@ -14,12 +14,12 @@ let
       description = "Administrative user ${user.name}.";
       group = user.name;
       extraGroups = [ "audio" "wheel" "network" ]
-        ++ (if config.services.xserver.enable then [ "input" ] else [])
-        ++ (if config.services.printing.enable then [ "cups" "lp" ] else [])
-        ++ (if config.virtualisation.docker.enable then [ "docker"] else []);
+        ++ (optional config.services.xserver.enable "input")
+        ++ (optionals config.services.printing.enable [ "cups" "lp" ])
+        ++ (optional config.virtualisation.docker.enable "docker");
       shell = "${pkgs.zsh}/bin/zsh";
       passwordFile = "${config.machine.secretPath}/${user.name}";
-      openssh.authorizedKeys.keyFiles = if config.services.openssh.enable then [ "${config.machine.secretPath}/${user.name}.pub" ] else [];
+      openssh.authorizedKeys.keyFiles = optional config.services.openssh.enable "${config.machine.secretPath}/${user.name}.pub";
     };
   };
 

pkgs/pkgsets.nix

@@ -4,7 +4,7 @@ with lib;
 
 let
   cfg = config.machine;
-  optPkgs = package: pkgstring: optionals (elem pkgstring cfg.pkgs) package;
+  optPkgs = package: pkgstring: optionals (elem pkgstring cfg.pkgs) (toList package);
   gitpkgs = import /nixpkgs {};
   stablepkgs = import <nixos-stable> {};
 
@@ -278,13 +278,13 @@ let
 in {
   environment.systemPackages =  base
                             ++ (optPkgs dict "dict")
-                            ++ (optPkgs [emacs] "emacs")
+                            ++ (optPkgs emacs "emacs")
                             ++ (optPkgs extra "extra")
                             ++ (optPkgs mail_utils "mailutils")
                             ++ (optPkgs cpp "cpp")
-                            ++ (optPkgs [haskell] "haskell")
+                            ++ (optPkgs haskell "haskell")
                             ++ (optPkgs java "java")
-                            ++ (optPkgs [python3] "python3")
+                            ++ (optPkgs python3 "python3")
                             ++ (optPkgs rustpkgs "rustpkgs")
                             ++ (optPkgs server "server")
                             ++ (optPkgs uniProgs "uniProgs")

services/openssh.nix

@@ -16,8 +16,7 @@ mkIf (elem "openssh" config.machine.services) {
     passwordAuthentication = false;
     permitRootLogin = "no";
     extraConfig = let users = concatMapStrings (user: "${user.name} ") config.machine.administrators
-      + (if config.services.gitea.enable then (config.services.gitea.user + " ") else "")
-      + (if config.services.nix-serve.enable then "nix-ssh" else "");
+      + (optionalString config.services.gitea.enable (config.services.gitea.user + " "));
     in  ''
         UsePAM no
         AllowUsers ${users}