--- a/core/src/luan/Luan.java	Tue Mar 29 19:58:39 2016 -0600
+++ b/core/src/luan/Luan.java	Tue Mar 29 20:39:14 2016 -0600
@@ -85,5 +85,61 @@
 		return s;
 	}
 
+
+	// from LuanState
+
+	public static Boolean checkBoolean(Object obj) throws LuanException {
+		if( obj instanceof Boolean )
+			return (Boolean)obj;
+		throw new LuanException("attempt to use a " + Luan.type(obj) + " value as a boolean" );
+	}
+
+	public static String checkString(Object obj) throws LuanException {
+		if( obj instanceof String )
+			return (String)obj;
+		throw new LuanException("attempt to use a " + Luan.type(obj) + " value as a string" );
+	}
+
+	public static LuanFunction checkFunction(Object obj) throws LuanException {
+		if( obj instanceof LuanFunction )
+			return (LuanFunction)obj;
+		throw new LuanException("attempt to call a " + Luan.type(obj) + " value" );
+	}
+
+	public static boolean isLessThan(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof Number && o2 instanceof Number ) {
+			Number n1 = (Number)o1;
+			Number n2 = (Number)o2;
+			return n1.doubleValue() < n2.doubleValue();
+		}
+		if( o1 instanceof String && o2 instanceof String ) {
+			String s1 = (String)o1;
+			String s2 = (String)o2;
+			return s1.compareTo(s2) < 0;
+		}
+		LuanFunction fn = getBinHandler("__lt",o1,o2);
+		if( fn != null )
+			return checkBoolean( Luan.first(fn.call(luan,new Object[]{o1,o2})) );
+		throw new LuanException( "attempt to compare " + Luan.type(o1) + " with " + Luan.type(o2) );
+	}
+
+	public static LuanFunction getBinHandler(String op,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof LuanTable ) {
+			LuanFunction f1 = getHandlerFunction(op,(LuanTable)o1);
+			if( f1 != null )
+				return f1;
+		}
+		return o2 instanceof LuanTable ? getHandlerFunction(op,(LuanTable)o2) : null;
+	}
+
+	public static LuanFunction getHandlerFunction(String op,LuanTable t) throws LuanException {
+		Object f = t.getHandler(op);
+		if( f == null )
+			return null;
+		return checkFunction(f);
+	}
+
+
+
 	private Luan() {}  // never
 }