code: function redirect(url) {
      var path = u.urlPath(url);
      var params = u.urlParams(url);
  
      var pg = generator.aliase$[path];
      if (pg) return { status:301, url:pg._href + params };
  
      pg = generator.redirect$[path];
      if (pg) return { status:302, url:pg._href + params };
  
      // customRedirects return params also
      pg = generator.customRedirect && generator.customRedirect(url);
      if (pg) return { status:301, url:pg };
    }
docs: compute alias or custom redirect for a url - returns falsy if none 302 redirects are temporary - browsers won't try to remember them 301 redirects are permanent - browsers will cache and avoid re-requesting