title: Selecting vector elements from dynamic indices using Specter
body: <p>I have a vector <code>[:a :b :c :d :e]</code> and some indices <code>[1 2 4]</code>.</p>
  
  <p>Using Specter, how to select the elements of my vector from the indices, so that it returns <code>[:b :c :e]</code>?</p>