title: Decrement index in a loop after Swift C-style loops deprecated
body: <p>How would you express a decrementing indexed loop in Swift 3.0, where the syntax below is not valid any more?</p>
  
  <pre><code>for var index = 10 ; index &gt; 0; index-=1{
     print(index)
  }
  
  // 10 9 8 7 6 5 4 3 2 1
  </code></pre>