How might I determine the XPath of a DOM element?

In JavaScript, supposing I have a reference to an element, how do I retrieve an XPath expression that would select it?

Is there something like objElement.xpath?

From stackoverflow Annibigi

• This is not XPATH related, but just to show you how you can get the parent/child relationship with a damn simple while loop.

  var pathAt = function(node) {
      var stack = [];
      while(node.parentNode !== null) {
          stack.unshift(node.tagName);
          node = node.parentNode;
      }
      return stack.join('/');
  }
  
  // Usage : pathAt(document.getElementBy('moo'));
  // Outputs : "HTML/BODY/CENTER/TABLE/TBODY/TR/TD/TABLE/TBODY/TR/TD/TABLE/TBODY/TR/TD/TABLE/TBODY/TR/TD"
  

  Aaron Digulla : You also need to include the index for elements which can appear multiple times as a child (think DIV or P).
  From SleepyCod

• Since Annibigi doesn't want to post the solution, I'll do it: See this snippet.

  From Aaron Digulla