--- a/src/luan/interp/LenExpr.java	Sun Dec 16 09:23:56 2012 +0000
+++ b/src/luan/interp/LenExpr.java	Tue Dec 18 07:05:58 2012 +0000
@@ -3,6 +3,7 @@
 import luan.Lua;
 import luan.LuaNumber;
 import luan.LuaTable;
+import luan.LuaFunction;
 import luan.LuaException;
 
 
@@ -13,18 +14,18 @@
 	}
 
 	@Override public Object eval(LuaStateImpl lua) throws LuaException {
-		return new LuaNumber( length(op.eval(lua)) );
-	}
-
-	private static int length(Object obj) throws LuaException {
-		if( obj instanceof String ) {
-			String s = (String)obj;
-			return s.length();
+		Object o = op.eval(lua);
+		if( o instanceof String ) {
+			String s = (String)o;
+			return new LuaNumber( s.length() );
 		}
-		if( obj instanceof LuaTable ) {
-			LuaTable t = (LuaTable)obj;
+		LuaFunction fn = Utils.getHandler("__len",o);
+		if( fn != null )
+			return Utils.first(fn.call(lua,o));
+		if( o instanceof LuaTable ) {
+			LuaTable t = (LuaTable)o;
 			return t.length();
 		}
-		throw new LuaException( "attempt to get length of a " + Lua.type(obj) + " value" );
+		throw new LuaException( "attempt to get length of a " + Lua.type(o) + " value" );
 	}
 }