Strigi now understands Xesam queries

Flavio wrote about Strigi getting Xesam query support, which is cool and allows me to look up email from me to a friend using this query:

<request>
  <query>
  <and>
    <equals>
      <field name="email.to"/>
      <string>Christoph</string>
    </equals>
    <equals>
      <field name="email.from"/>
      <string>Egon</string>
    </equals>
  </and>
  </query>
</request>

So that, after having saved the above as query.xml, I can then issue a strigicmd call:

strigicmd xesamquery -t clucene -d index/ -q query.xml

Now, with proper nesting and all functional (see the full query language specification), I can do all sorts of nice queries:

<request>
  <query>
    <equals>
      <field name="xml.usesNamespace"/>
      <string caseSensitive="true">http://www.xml-cml.org/schema</string>
    </equals>
  </query>
</request>

Possibly embedded in XHTML (or vice versa):

<request>
  <query>
    <and>
      <equals>
        <field name="xml.usesNamespace"/>
        <string caseSensitive="true">http://www.xml-cml.org/schema</string>
      </equals>
      <equals>
        <field name="xml.usesNamespace"/>
        <string caseSensitive="true">http://www.w3.org/1999/xhtml</string>
      </equals>
    </and>
  </query>
</request>

And, after having installed strigi-chemical currently developed by Alexandr, the GSoC student on chemistry support for Strigi, chemical queries. For example, to get all molecules with a certain mass range, I can find all files that use a CML namespace:

<request>
  <query>
    <and>
      <greaterThan>
        <field name="chemistry.molecular_weight"/>
        <float>50</float>
      </greaterThan>
      <lessThan>
        <field name="chemistry.molecular_weight"/>
        <float>59</float>
      </lessThan>
    </and>
  </query>
</request>

Or, give me all chemical files which contains a molecule with 'butane' in the name:

<request>
  <query>
    <and>
      <contains>
        <field name="content.mime_type"/>
        <string>chemistry</string>
      </contains>
      <contains>
        <field name="chemistry.name"/>
        <string>butane</string>
      </contains>
    </and>
  </query>
</request>