title: What does a fullstop or period or dot (.) mean in Haskell?
body: <p>I really wish that Google was better at searching for syntax:</p>
  
  <pre><code>decades         :: (RealFrac a) =&gt; a -&gt; a -&gt; [a] -&gt; Array Int Int
  decades a b     =  hist (0,9) . map decade
                     where decade x = floor ((x - a) * s)
                           s        = 10 / (b - a)
  </code></pre>