--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/luan/impl/LenExpr.java	Sun Jun 22 04:17:38 2014 +0000
@@ -0,0 +1,37 @@
+package luan.impl;
+
+import luan.Luan;
+import luan.LuanTable;
+import luan.LuanFunction;
+import luan.LuanException;
+import luan.LuanSource;
+import luan.LuanBit;
+
+
+final class LenExpr extends UnaryOpExpr {
+
+	LenExpr(LuanSource.Element se,Expr op) {
+		super(se,op);
+	}
+
+	@Override public Object eval(LuanStateImpl luan) throws LuanException {
+		Object o = op.eval(luan);
+		if( o instanceof String ) {
+			String s = (String)o;
+			return s.length();
+		}
+		if( o instanceof byte[] ) {
+			byte[] a = (byte[])o;
+			return a.length;
+		}
+		LuanBit bit = luan.bit(se);
+		LuanFunction fn = bit.getHandlerFunction("__len",o);
+		if( fn != null )
+			return Luan.first(bit.call(fn,"__len",new Object[]{o}));
+		if( o instanceof LuanTable ) {
+			LuanTable t = (LuanTable)o;
+			return t.length();
+		}
+		throw bit.exception( "attempt to get length of a " + Luan.type(o) + " value" );
+	}
+}