title: Adding RegEx to Linq method syntax
body: <p>I have the following linq code:</p>
  
  <pre><code>var join = enterpriseContext.Parties
           .Join(enterpriseContext.ActiveDealerContactsViews,
              p =&gt; p.party_id,
               v =&gt; v.Party_id,
               (p, v) =&gt; new { PartySite = p, View = v })
           .Where(p =&gt; p.PartySite.party_id == partyId)
  </code></pre>
  
  <p>And I would like to add another .where expression using a regex check, e.g.</p>
  
  <p>.where (v => v.View.System_id.IsMatch(regEx));</p>
  
  <p>But it does not compile.</p>
  
  <p>Thanks
  Alex</p>