[Xapian-discuss] Re: search result context.

[Jean-Francois Dockes]

Charles Brandt <lists <at> st.imul.us> writes:
> It sounds like saving the whole document to the xapian Document's data field
> would bog down the search database.  That makes sense that you would need
> the whole document for context display, I just wasn't sure if there was some
> built in function that could rebuild pieces based on the position
> information.
> 
> I'll be interested to hear if anyone else has built such a system.  If not
> maybe I'll get to it someday. :)

As I had been thinking of this for some time, I just tried it, the basic thing
is actually a few lines of code:

Xapian::TermIterator term;
for (term = db->termlist_begin(docid);term != db->termlist_end(docid); term++) {
    Xapian::PositionIterator pos;
    for (pos = db->positionlist_begin(docid, *term); 
       pos != db->positionlist_end(docid, *term); pos++) {
       if (buf.size() < *pos)
          buf.resize((*pos)+1);
       buf[(*pos)] = *term;
    }
}
for (vector<string>::iterator it = buf.begin(); it != buf.end(); it++) {
    cout << *it << " ";
}

The code is very rough, there might be several terms at the same pos, etc... I
just wanted to see what came out, and the problem is, it's not very readable. It
does seem that punctuation and capitalization are good for something finally :)
An example follows.

Regards,
J.F. Dockes

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