use Perl

• We could wirte a CSS - XPath transator (Score:1)

  by dakkar (5832)

  You know, CSS selectors are just a different syntax for a subset of XPath, so we could write a translator from CSS to XPath. I might even get a shot to that...
  • Re: (Score:1)

    by miyagawa (1653)

    Yeah, that sounds about right. But does XPath support alternatives and sibling, like "h1 + h2" (h2 that follows immediately after h1)?
    • Re: (Score:1)

      by Aristotle (5147)

      Yes.

      h1/following-sibling::*[1]/self::h2
      • Re: (Score:1)

        by miyagawa (1653)

        Neato. If Xpath can do all of what can be done with CSS2 selectors [w3.org], translating (or compiling) the CSS selector exp to XPath is da way to go. The benefit of CSS selector is that it's much easier to write than XPath.
        
        Googling "CSS selector to XPath" gives me pretty few results:
        http://groups.google.com/group/behaviour/browse_thread/thread/246782199cea5ce9/a 2530a4abe5b12fd?lnk=gst&rnum=1#a2530a4abe5b12fd [google.com]
        http://www.joehewitt.com/blog/2006-03-20.php [joehewitt.com]
        • Re: (Score:1)

          by Aristotle (5147)

          It should not be very hard. There are not many selectors in CSS2 and they just need to be translated once. Maybe I should write up the equivalents.
        • Re: (Score:1)

          by Aristotle (5147)

          Here you go: How to map CSS selectors to XPath queries [plasmasturm.org].
          • Re: (Score:1)

            by miyagawa (1653)

            That's a great one. Thank you!
            
            What about CSS 3 Selectors (Pseudo classes)? [w3.org] Looks like html/selector.rb implements some of those, e.g. :root, :empty, :only-child etc.
• Porting html/selector.rb to perl (Score:1)

  by miyagawa (1653)

  http://labnotes.org/svn/public/ruby/scrapi/lib/html/selector.rb [labnotes.org] is the ruby code which is really clean, and it'd be pretty straightforward (but boring) to port to Perl.
  • Re: (Score:2)

    by bart (450)

    Can anybody recommend a quick tutorial to Ruby? I find this piece of source code extremely hard to read. That's because I'm not getting some of the basics in Ruby, of course.