anchor.diff:                  </ul>
                 </li>
               '' else ''
  -              <li class="${if page.path == currentItem.url then "active" else ""}">
  +              <li class="${if (stripIndexHtml page.path) == currentItem.url then "active" else ""}">
                   ${if currentItem ? pre then ''
                     <a href="${currentItem.url}">
                       <img alt="${currentItem.name}" src="/img/${currentItem.pre}" width="20px">
  
positive.code:     site = env.conf.theme.site;
      lib = env.lib;
      page = args.page;
    in ''
  ${if page.path == "/index.html" then ''
    <nav id="menu" class="navbar navbar-default navbar-fixed-top" data-spy="affix" data-offset-top="200" role="navigation">
  
negative.code:                   ${
                      let
                        renderChild = child: ''
                          <li class="${if (stripIndexHtml page.path) == child.url then "active" else ""}">
                            <a href="${child.url}">${child.name}</a>
                          </li>
                        '';
  