--- a/src/luan/Luan.java	Thu Apr 10 18:48:50 2025 -0600
+++ b/src/luan/Luan.java	Fri Apr 11 11:43:12 2025 -0600
@@ -415,9 +415,12 @@
 	}
 
 	public static LuanFunction checkFunction(Object obj) throws LuanException {
+		return checkFunction(obj,"");
+	}
+	public static LuanFunction checkFunction(Object obj,String s) throws LuanException {
 		if( obj instanceof LuanFunction )
 			return (LuanFunction)obj;
-		throw new LuanException("attempt to call a " + Luan.type(obj) + " value" );
+		throw new LuanException("attempt to call a " + Luan.type(obj) + " value" + s );
 	}
 
 	public LuanFunction load(String text,String sourceName,boolean persist,LuanTable env)

--- a/src/luan/impl/LuanParser.java	Thu Apr 10 18:48:50 2025 -0600
+++ b/src/luan/impl/LuanParser.java	Fri Apr 11 11:43:12 2025 -0600
@@ -524,7 +524,7 @@
 		Stmts stmt = new Stmts();
 		stmt.add( "LuanFunction "+fnVar+" = Luan.checkFunction(" );
 		stmt.addAll( expr );
-		stmt.add( ");  " );
+		stmt.add( ",\" in a for statement\");  " );
 		stmt.add( "while(true) {  " );
 		stmt.addAll( makeLocalSetStmt(names,fnExp) );
 		stmt.add( "if( " );

--- a/src/luan/modules/swing/Swing.luan	Thu Apr 10 18:48:50 2025 -0600
+++ b/src/luan/modules/swing/Swing.luan	Fri Apr 11 11:43:12 2025 -0600
@@ -1,12 +1,32 @@
 local Luan = require "luan:Luan.luan"
 local error = Luan.error
+local ipairs = Luan.ipairs or error()
 require "java"
+local System = require "java:java.lang.System"
 local Insets = require "java:java.awt.Insets"
+local UIManager = require "java:javax.swing.UIManager"
 local SwingLuan = require "java:luan.modules.swing.SwingLuan"
 
 
 local Swing = {}
 
+System.setProperty("apple.laf.useScreenMenuBar", "true")
+
+function Swing.get_installed_look_and_feels()
+	local list = {}
+	for _, info in ipairs{UIManager.getInstalledLookAndFeels()} do
+		list[#list+1] = info.getClassName()
+	end
+	return list
+end
+
+function Swing.get_look_and_feel()
+	return UIManager.getLookAndFeel().getClass().getName()
+end
+
+Swing.ui_manager_put = UIManager.put
+Swing.set_look_and_feel = UIManager.setLookAndFeel
+
 Swing.run = SwingLuan.run
 
 Swing.new_insets = Insets.new  -- top, left, bottom, right

--- a/src/luan/modules/swing/SwingLuan.java	Thu Apr 10 18:48:50 2025 -0600
+++ b/src/luan/modules/swing/SwingLuan.java	Fri Apr 11 11:43:12 2025 -0600
@@ -2,16 +2,13 @@
 
 import java.lang.reflect.InvocationTargetException;
 import javax.swing.SwingUtilities;
-import javax.swing.UIManager;
 import javax.swing.KeyStroke;
 import javax.swing.Action;
 import javax.swing.AbstractAction;
 import javax.swing.JComponent;
-import javax.swing.UnsupportedLookAndFeelException;
 import javax.swing.text.JTextComponent;
 import javax.swing.text.Document;
 import javax.swing.undo.UndoManager;
-import java.awt.Color;
 import java.awt.event.ActionListener;
 import java.awt.event.ActionEvent;
 import java.awt.event.WindowListener;
@@ -29,33 +26,6 @@
 public class SwingLuan {
 	private static final Logger logger = LoggerFactory.getLogger(SwingLuan.class);
 
-	static {
-		//System.setProperty("apple.awt.application.name", "MyApplication");
-		System.setProperty("apple.laf.useScreenMenuBar", "true");
-		//System.out.println(UIManager.getLookAndFeel());
-/*
-		for (UIManager.LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
-			logger.info(info.toString());
-		}
-*/
-		UIManager.put("control",new Color(0xedeff2));
-		try {
-			//UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
-			//UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
-			UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");
-			//UIManager.setLookAndFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel");
-			//UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
-		} catch(ClassNotFoundException e) {
-			throw new RuntimeException(e);
-		} catch(InstantiationException e) {
-			throw new RuntimeException(e);
-		} catch(IllegalAccessException e) {
-			throw new RuntimeException(e);
-		} catch(UnsupportedLookAndFeelException e) {
-			throw new RuntimeException(e);
-		}
-	}
-
 	private static void exception(LuanException e) {
 		System.err.println(e.getLuanStackTraceString());
 		System.exit(1);