Idea collection

XPath localization paths

[ ] ancestor
- http://doc.ddart.net/xmlsdk/htm/xpath_syntax2_3prn.htm
- examples:
  - Find the nearest book ancestor of the current element: ancestor::book[1]
  - Find the nearest ancestor book that has an author element: ancestor::book[author][1]
  - Find the nearest ancestor author element that is contained in a book element: ancestor::author[parent::book][1]
[ ] preceding-sibling
[ ] preceding
- might not work well with hashes
- still useful, as data could be tied to Tie::IxHash?
- else ignore the wrong order, it’s the user’s responsibility to (not) use it this way, as it is the same with ordinary perl % and @

Functions for node collections