title: NILL value in haskell
body: <p>I get input (x) from user, convert it to Int by let y = (read x)::Int and then I would like the function to behave in a special way if user gave nothing (empty string).</p>
  
  <pre><code>-- In this place I would like to handle situation in which user
  -- gave empty string as argument
  -- this doesnt work :/
  yearFilter [] y = True
  
  --This works fine as far as y is integer
  yearFilter x y  | x == (objectYear y) = True
                  | otherwise = False
  </code></pre>
  
  <p>Thanks for help,
  Bye</p>