title: invalid regexp group
body: <p>I have regular expression </p>
  
  <p><code>(?&lt;=\s)(?:#sidebar-right-1|#BlogArchive1|#ArchiveList|#BlogArchive1_ArchiveList|#PopularPosts)(?=\s|{)</code></p>
  
  <p>I got syntax error invalid regex group. Where is problem?</p>
  
  <p>I applied it like this:</p>
  
  <p>rules[r].selectorText.match(new RegExp(ids, 'gm'))</p>