title: Haskell: Why is extra space needed in arithmetic sequence for user defined enum?
body: <p>So for any built-in types in Haskell, I can construct an arithmetic sequence, like this one (for <code>Int</code> or <code>Integer</code>, etc.)</p>
  
  <pre><code>[1..5]
  </code></pre>
  
  <p>But if I define an enum type like:</p>
  
  <pre><code>data Suit = Club | Diamond | Heart | Spade deriving (Show, Enum) 
  </code></pre>
  
  <p>when I create an arithmetic sequence, I have to include space before an enum instance and the dot dot e.g.</p>
  
  <pre><code>[Club .. Diamond]
  </code></pre>
  
  <p>Why?</p>