iRule and trailing slash issue

when HTTP_REQUEST {
   if { [string tolower [HTTP::uri]] starts_with "/dev3" } {
       Set the pool to dev3 for all requests starting with /dev3
      pool dev3
       Remove /dev3 from the URI
      set uri [string range [HTTP::uri] 5 end]
       Check if updated URI has a length
      if {$uri}{
          Updated URI has a length, so set the request to the updated URI
         HTTP::uri $uri
      } else {
          Updated URI was empty, so set the URI to /
         HTTP::uri /
      }
   }
}