From 11472a05010c6c74940d980e08d4297f66e051a3 Mon Sep 17 00:00:00 2001
From: Nicolas Pierron <nicolas.b.pierron@gmail.com>
Date: Wed, 30 Mar 2011 11:18:10 +0000
Subject: Add mkAssert.

svn path=/nixpkgs/trunk/; revision=26600
---
 pkgs/lib/properties.nix | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'pkgs/lib')

diff --git a/pkgs/lib/properties.nix b/pkgs/lib/properties.nix
index 46854d0e1431..d7df14f716f5 100644
--- a/pkgs/lib/properties.nix
+++ b/pkgs/lib/properties.nix
@@ -223,6 +223,11 @@ rec {
       content = mkNotdef;
     };
 
+  mkAssert = assertion: message: content:
+    mkIf
+      (if assertion then true else throw "\nFailed assertion: ${message}")
+      content;
+
   # Remove all "If" statement defined on a value.
   rmIf = foldProperty (
       foldFilter isIf
-- 
cgit 1.4.1