title: How do I make a list of all possible replaced items in Haskell?
body: <p>My input is an arbitrary list, such as</p>
  
  <pre><code>["a","b","c"]
  </code></pre>
  
  <p>and another list element, say <code>"z"</code>. I want the output to look like:</p>
  
  <pre><code>[["z","b","c"],["a","z","c"],["a","b","z"]]
  </code></pre>
  
  <p>How do I do this?</p>