public void Len(int idx)
{
var val = stack.get(idx);
if (LuaValue.isString(val))
{
var s = LuaValue.toString(val);
stack.push((long)s.Length);
}
else if (LuaValue.isLuaTable(val))
{
var t = LuaValue.toLuaTable(val);
stack.push((long)t.len());
}
else
{
throw new Exception("length error!");
}
}