nixos/local/lib/default.nix

lib:
{
	attrsToList = Attrs: builtins.map ( name: { inherit name; value = Attrs.${name}; } ) ( builtins.attrNames Attrs );
	mkConditional = condition: trueResult: falseResult: let inherit (lib) mkMerge mkIf; in
		mkMerge [ ( mkIf condition trueResult ) ( mkIf (!condition) falseResult ) ];

	# Behaviors of these two NixOS modules would be different:
	# { pkgs, ... }@inputs: { environment.systemPackages = [ pkgs.hello ]; }
	# inputs: { environment.systemPackages = [ pkgs.hello ]; }
	# The second one would failed to evaluate because nixpkgs would not pass pkgs to it.
	# So that we wrote a wrapper to make it always works like the first one.
	mkModules = moduleList: { pkgs, ... }@inputs:
	{
		imports = builtins.map
		(
			let handle = module:
				if ( builtins.typeOf module ) == "path" then handle import module
				else if ( builtins.typeOf module ) == "lambda" then module inputs
				else module;
			in handle
		) moduleList;
	};

	# from: https://github.com/NixOS/nix/issues/3759
	stripeTabs = text:
		let
			# Whether all lines start with a tab (or is empty)
			shouldStripTab = lines: builtins.all (line: (line == "") || (lib.strings.hasPrefix "	" line)) lines;
			# Strip a leading tab from all lines
			stripTab = lines: builtins.map (line: lib.strings.removePrefix "	" line) lines;
			# Strip tabs recursively until there are none
			stripTabs = lines: if (shouldStripTab lines) then (stripTabs (stripTab lines)) else lines;
		in
			# Split into lines. Strip leading tabs. Concat back to string.
			builtins.concatStringsSep "\n" (stripTabs (lib.strings.splitString "\n" text));
}