title: laziness and function composition (haskell, erlang)
body: <p>Can someone please explain or give some resources on how function composition works in relation to laziness?</p>
  
  <p>For example how does <code>filter (/='W') . map toUpper $ "justaword"</code> work in Haskell compared to it's counterpart in erlang which is not lazy?</p>