From e2c858da3481213f7fd74ddfc9ed393bd47f608d Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@slava-pestovs-macbook-pro.local>
Date: Fri, 10 Apr 2009 06:20:23 -0500
Subject: [PATCH] Add better error check for 'window' word

---
 basis/ui/ui.factor | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/basis/ui/ui.factor b/basis/ui/ui.factor
index dff7726d08..1de3912f28 100644
--- a/basis/ui/ui.factor
+++ b/basis/ui/ui.factor
@@ -12,7 +12,10 @@ IN: ui
 ! Assoc mapping aliens to gadgets
 SYMBOL: windows
 
-: window ( handle -- world ) windows get-global at ;
+ERROR: no-window handle ;
+
+: window ( handle -- world )
+    windows get-global ?at [ no-window ] unless ;
 
 : window-focus ( handle -- gadget ) window world-focus ;