title: RegEx: How to apply a Character Set restriction to a whole Expression
body: <p>Let's say I have a regex which is used to validate email addresses, such as:</p>
  
  <pre><code>/^(([^&lt;&gt;()\[\]\\.,;:\s@"]+(\.[^&lt;&gt;()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
  </code></pre>
  
  <p>Now, let's say I also want to make sure that the following character set applies to the whole string too:</p>
  
  <pre><code>[\x00-\x7F]
  </code></pre>
  
  <p>How would I go about applying this 2nd character set restriction to the whole pattern.</p>
  
  <p>Result would be that:</p>
  
  <ul>
  <li>jake.howlett@howlett.house (passes)</li>
  <li>jake.howẟlett@howlett.house (fails, as the ẟ is outside of the 2nd character set)</li>
  </ul>