issue #135 bugfix

README.md

@@ -383,8 +383,7 @@ require'navigator'.setup({
 
 ### Try it your self
 
-In `playground` folder, there is a `init.lua` and source code for you to play with. Check [playground/README.md](https://github.com/ray-x/navigator.lua/blob/master/playground/README.md) for more
-details
+In `playground` folder, there is a `init.lua` and source code for you to play with. Check [playground/README.md](https://github.com/ray-x/navigator.lua/blob/master/playground/README.md) for more details
 
 ### Default keymaps
 

lua/navigator/util.lua

@@ -395,6 +395,10 @@ function M.empty(t)
   if t == nil then
     return true
   end
+
+  if type(t) ~= 'table' then
+    return false
+  end
   return next(t) == nil
 end