title: Finding every second element in a repeating pattern
body: <p>Data with repeated 'i's followed by 'i's and/or 't's. </p>
  
  <pre><code>data = ['i','t','t','i','i','t','t','t']
  </code></pre>
  
  <p>Trying to retrieve the index of the last 't' in the pattern ['i','t','t']:</p>
  
  <pre><code>[2,6] // ['i','t','t','i','i','t','t','t'] # position of the returned 't's
        //   _______ ^       _______ ^
  </code></pre>
  
  <p>I'm looking for a non-recursive solution using (pure) functions only, using ramdajs for example.</p>
  
  <p>Tried to use <code>reduce</code> and <code>transduce</code>, but unsuccessful sofar.</p>