Bill the Plumber

I wrote a Link header parser in Javascript. Thanks Mark Nottingham for sending me a link to his python equivalent.

var linkexp=/<[^>]*>\s*(\s*;\s*[^\(\)<>@,;:"\/\[\]\?={} \t]+=(([^\(\)<>@,;:"\/\[\]\?={} \t]+)|("[^"]*")))*(,|$)/g;
var paramexp=/[^\(\)<>@,;:"\/\[\]\?={} \t]+=(([^\(\)<>@,;:"\/\[\]\?={} \t]+)|("[^"]*"))/g;

function unquote(value)
{
    if (value.charAt(0) == '"' && value.charAt(value.length - 1) == '"') return value.substring(1, value.length - 1);
    return value;
}

function parseLinkHeader(value)
{
   var matches = value.match(linkexp);
   var rels = new Object();
   var titles = new Object();
   for (i = 0; i < matches.length; i++)
   {
      var split = matches[i].split('>');
      var href = split[0].substring(1);
      var ps = split[1];
      var link = new Object();
      link.href = href;
      var s = ps.match(paramexp);
      for (j = 0; j < s.length; j++)
      {
         var p = s[j];
         var paramsplit = p.split('=');
         var name = paramsplit[0];
         link[name] = unquote(paramsplit[1]);
      }

      if (link.rel != undefined)
      {
         rels[link.rel] = link;
      }
      if (link.title != undefined)
      {
         titles[link.title] = link;
      }
   }
   var linkheader = new Object();
   linkheader.rels = rels;
   linkheader.titles = titles;
   return linkheader;
}

I had written a non-regular-expression, hand-coded parser in Java for RESTEasy. Thought it might be faster than regexp. That could probably be ported to Javascript too.