title: How to declare type of multiple variables in same line
body: <p>Suppose my Haskell file contains following declarations.</p>
  
  <pre><code>a :: Integer
  b :: Double
  c :: String
  
  a = 10
  b = 12.34
  c = "Abcd"
  </code></pre>
  
  <p>I am able to assign values to variables in same line like below.</p>
  
  <pre><code> (a, b, c) = (10, 12.34, "Abcd")
  </code></pre>
  
  <p>My question is, how can I define the type signature in same line?</p>
  
  <p>When I used following statement.</p>
  
  <pre><code>  (a, b, c) :: (Integer, Double, String)
  </code></pre>
  
  <p>I am getting following error.</p>
  
  <pre><code>Invalid type signature: (a, b, c) :: (Integer, Double, String)
      Should be of form &lt;variable&gt; :: &lt;type&gt;
  </code></pre>