A filter for RSS feeds

Stew has introduced the google-code-project where is hosted OpenRevien (the source code of Postgenomic). This gave me the idea to host feedfilter a program filtering rss feeds that I wrote quickly a few days ago. My project is hosted at http://code.google.com/p/feedfilter/. It's a small java program running as a CGI (you don't need tomcat or either..). A parameter in the cgi is used to filter the feeds:

Examples:

PNAS - RSS feed of Early Edition articles: keep posts containing the word "protein"
feed("http://www.pnas.org/rss/ahead.xml",contains("protein"))


PNAS - RSS feed of Early Edition articles: keep posts NOT containing the words "[IMMUNOLOGY]" or "[geology]"
feed("http://www.pnas.org/rss/ahead.xml",NOT(OR(contains("[IMMUNOLOGY]"),contains("[geology]"))))

RSS feeds from connotea about tag=bioinformatics where author is not dc:creator=lindenb
feed("http://www.connotea.org/rss/tag/bioinformatics",not(equals("dc:creator","lindenb")))

Syntax
input: feed( <url:string>, <node> )
node: AND( <node> , <node> )
| OR( <node> , <node> )
| NOT( <node> )
| contains( <qName:string>,<value:string>)
| contains( <value:string>)
| equals( <qName:string>,<value:string>)
| equals( <value:string>)
| regex( <qName:string>,<java regular expression:string>)
| regex( <java regular expression:string>)




Pierre