DOM XPath

If someone ever decides to write down DOM XPath (i.e. a proper version of the DOM3XPath note), take this into account:

• Integrate the XPath part of the section Interactions with XPath and XSLT from HTML.
• Make it clear that contrary to XPath 1.0 multiple Text nodes can indeed be returned, even if they are siblings. The DOM is not the XML InfoSet. (As is the case in WebKit and Gecko today.)
• Simplifications: http://lists.w3.org/Archives/Public/public-webapps/2011AprJun/0310.html
• Exceptions: https://bugzilla.mozilla.org/show_bug.cgi?id=743888

WebIDL interfaces

[Constructor]
interface XPathEvaluator {
  XPathExpression    createExpression(DOMString expression, 
                                      XPathNSResolver resolver);
  XPathNSResolver    createNSResolver(Node nodeResolver);
  object             evaluate(DOMString expression, 
                              Node contextNode, 
                              XPathNSResolver resolver, 
                              unsigned short type, 
                              object result);
};