XML::XPath is not the only XPath implementation you can look at: XML::Filter::Dispatcher which has a complete XPath parser (at least you can reuse the YAPP grammar). You could also look at the way libxml2 (the base for XML::LibXML) does it. Even though it is written in C you might be able to re-use the data structure and the algorithms.

Finally, XPath is quite a complex standard, that goes way beyond the simple directory-like syntax that you are showing, it includes predicates, function calls... so it might not be easy to get a fast implementation of all of this (i.e a structure that speeds-up some queries might not be quite appropriate for others). DB-XML actually maintains user-defined XPath queries as indexes, that might be a good strategy.

In reply to Re: Idea for XPath implementation by mirod
in thread Idea for XPath implementation by Jaap

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.