title: Convert array of tuples to JSON in Haskell
body: <p>Would ayone know how to convert </p>
  
  <pre><code>tt :: (Int, [(Int, String)])
  tt = (777, [(1, "AA") , (2, "BB") , (3, "CC")])
  </code></pre>
  
  <p>to JSON similar to</p>
  
  <pre><code>{
  "user": 777,
  "data": [ 
              { "num": 1 , "typ": "AA" },
              { "num": 2 , "typ": "BB" },
              { "num": 3 , "typ": "CC" } 
          ]
  }
  </code></pre>
  
  <p>using (preferably) Aeson ? </p>