title: Laravel pattern validation pipe character issue
body: <p>Using the Laravel framework I need to check the value of a submitted field against a set of valid values.</p>
  
  <p>The problem is Laravel uses the | character to separate validation rules belonging to a field.</p>
  
  <p>This does <em>not</em> work, it throws a</p>
  
  <blockquote>
    <p>"preg_match: No ending delimiter '/' found":</p>
  </blockquote>
  
  <pre><code>'my_field' =&gt; 'match:/^(value1|value2|different value|yet another)$/'
  </code></pre>
  
  <p>How does one escapes the <code>|</code> character in this case if the <code>\</code> character does not help?</p>