title: How do I insert values between each element of a list?
body: <p>This (<a href="https://play.rust-lang.org/?version=stable&amp;mode=debug&amp;edition=2018&amp;gist=7e172371cae5ed2e0a692aa2a1416b15" rel="nofollow noreferrer">playground</a>):</p>
  <pre class="lang-rust prettyprint-override"><code>let s = &quot;Hello world!&quot;;
  let splitted_string = s.split_terminator(&quot;&quot;).skip(1).collect::&lt;Vec&lt;&amp;str&gt;&gt;();
  println!(&quot;splitted_string: {:?}&quot;, splitted_string);
  </code></pre>
  <p>results in the following output:</p>
  <pre class="lang-none prettyprint-override"><code>splitted_string: [&quot;H&quot;, &quot;e&quot;, &quot;l&quot;, &quot;l&quot;, &quot;o&quot;, &quot; &quot;, &quot;w&quot;, &quot;o&quot;, &quot;r&quot;, &quot;l&quot;, &quot;d&quot;, &quot;!&quot;]
  </code></pre>
  <p>How can I insert an <code>a</code> between each element and obtain something like this?</p>
  <pre class="lang-none prettyprint-override"><code>[&quot;H&quot;, &quot;a&quot;, &quot;e&quot;, &quot;a&quot;, &quot;l&quot;, &quot;a&quot;, &quot;l&quot;, &quot;a&quot;, &quot;o&quot;, &quot;a&quot;, &quot; &quot;, &quot;a&quot;, &quot;w&quot;, &quot;a&quot;, &quot;o&quot;, &quot;a&quot;, &quot;r&quot;, &quot;a&quot;, &quot;l&quot;, &quot;a&quot;, &quot;d&quot;, &quot;a&quot;, &quot;!&quot;]
  </code></pre>