Xapian discuss - Nov 2008 - Get PositionList from the Mset

Hi,

I am new to this discuss group and I hope my question hasn't been asked
before.

I was trying to do the following: I have an enquiry and a database. After
performing the query I got the MSet. Now I would like to display the
positional information for the query terms in the MSet.

My thinking is that to display the positional information, I need the terms
and the DocIDs.

I used the MSetIterator to get Docids from the MSet, and from the query I
can get the query terms by query.get_terms_begin(). Now I have the query
terms and DocIDs, questions is how to get the positional information?

I guess it would be just a few lines of code. Could somebody help me out
please?

Thanks,

Kevin

On Wed, Nov 12, 2008 at 04:27:14PM -0500, zhiguo li wrote:
> I used the MSetIterator to get Docids from the MSet, and from the query I
> can get the query terms by query.get_terms_begin(). Now I have the query
> terms and DocIDs, questions is how to get the positional information?
Given a TermIterator, you can use positionlist_begin() to get a
PositionIterator, which will give you the position list within the
relevant document for the current term of the TermIterator.

You can use Enquire::get_matching_terms(MSetIterator&) to get a
TermIterator; this will iterate over only the terms in the current
query which actually match the current document. (Current in the sense
of the MSetIterator.)

I believe, but haven't checked, that this will do what you want.

J

-- 
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  James Aylett                                                  xapian.org
  james at tartarus.org                               uncertaintydivision.org