title: Simple way to accept only one form of delimiter and rejecting multiple types?
body: <p>I was wondering how I could go about making something that accepts a string with only one type of delimiter, something like this:</p>
  
  <pre><code>car:bus:boat
  </code></pre>
  
  <p>and rejecting something like:</p>
  
  <pre><code>car:bus-boat
  </code></pre>
  
  <p>I am not really sure about how to go about creating something like this.</p>