From a9b19788fb574871bd27054e77b361f7f1413319 Mon Sep 17 00:00:00 2001
From: Marc Weber <marco-oweber@gmx.de>
Date: Sun, 26 Oct 2008 17:44:23 +0000
Subject: [PATCH] simplified isOption reusing typeOf

svn path=/nixpkgs/trunk/; revision=13119
---
 pkgs/lib/default.nix | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/pkgs/lib/default.nix b/pkgs/lib/default.nix
index ece410ab55ab..851e9d72dc5c 100644
--- a/pkgs/lib/default.nix
+++ b/pkgs/lib/default.nix
@@ -347,12 +347,9 @@ rec {
 
   mkOption = attrs: attrs // {_type = "option";};
 
-  typeOf = x: if x ? _type then x._type else "";
+  typeOf = x: if (__isAttrs x && x ? _type) then x._type else "";
 
-  isOption = attrs:
-     __isAttrs attrs
-  && attrs ? _type
-  && attrs._type == "option";
+  isOption = attrs: (typeOf attrs) == "option";
 
   addDefaultOptionValues = defs: opts: opts //
     builtins.listToAttrs (map (defName: