title: Is there a Symfony helper for getting the current action URL and changing one or more of the query parameters?
body: <p>What I'd like to do is take the route for the current action along with any and all of the route and query string parameters, and change a single query string parameter to something else. If the parameter is set in the current request, I'd like it replaced. If not, I'd like it added. Is there a helper for something like this, or do I need to write my own?</p>
  
  <p>Thanks!</p>
  
  <p>[edit:] Man, I was unclear on what I actually want to do. I want to generate the URL for "this page", but change one of the variables. Imagine the page I'm on is a search results page that says "no results, but try one of these", followed by a bunch of links. The links would contain all the search parameters, except the one I would change per-link.</p>