Xapian discuss - Apr 2006 - QueryParser is strange with boolean filter

I have encountered something strange with QueryParser.
This is not critical because I have found how to avoid this
problem.

In the following results, D, E cases are something unexpected.
I could avoid this by changing the input string into the format  
as case F without plus sign in boolean filter terms.


1. version : xapian 0.9.4 version with UTF-8 patch

2. parse query source code
    qp = xapian.QueryParser()
    qp.set_database(database)
    qp.set_default_op(xapian.Query.OP_AND)
    qp.set_stemming_strategy(xapian.QueryParser.STEM_NONE)
    qp.add_boolean_prefix("XTYPE", "XTYPE:")
    query = qp.parse_query(input,
        xapian.QueryParser.FLAG_BOOLEAN |
        xapian.QueryParser.FLAG_BOOLEAN_ANY_CASE |
        xapian.QueryParser.FLAG_PHRASE |
        xapian.QueryParser.FLAG_LOVEHATE |
        xapian.QueryParser.FLAG_WILDCARD)
    print "Performing query '%s'" % query.get_description()

3. test result

Case A: OK
$ python search.py -v cup XTYPE:H XTYPE:V
Performing query 'Xapian::Query((cup:(pos=1) FILTER (XTYPE:H AND
XTYPE:V)))'

Case B: OK
$ python search.py -v cup +XTYPE:H +XTYPE:V
Performing query 'Xapian::Query((cup:(pos=1) FILTER (XTYPE:H AND
XTYPE:V)))'

Case C: OK
$ python search.py -v cup -XTYPE:H -XTYPE:V
Performing query 'Xapian::Query((cup:(pos=1) AND_NOT (XTYPE:H OR
XTYPE:V)))'

Case D: ?
$ python search.py -v cup -XTYPE:H +XTYPE:V
Performing query 'Xapian::Query((cup:(pos=1) FILTER (XTYPE:H AND
XTYPE:V)))'

Case E: ?
$ python search.py -v cup +XTYPE:H -XTYPE:V 
Performing query 'Xapian::Query((cup:(pos=1) FILTER (XTYPE:H AND
XTYPE:V)))'

Case F: OK
$ python search.py -v cup XTYPE:H -XTYPE:V 
Performing query 'Xapian::Query(((cup:(pos=1) AND_NOT XTYPE:V) FILTER
XTYPE:H))'



Sungsoo Kim

On Thu, Apr 13, 2006 at 11:37:44AM +0900, Sungsoo Kim
wrote:
> Case D: ?
> $ python search.py -v cup -XTYPE:H +XTYPE:V
> Performing query 'Xapian::Query((cup:(pos=1) FILTER (XTYPE:H AND
XTYPE:V)))'
> 
> Case E: ?
> $ python search.py -v cup +XTYPE:H -XTYPE:V 
> Performing query 'Xapian::Query((cup:(pos=1) FILTER (XTYPE:H AND
XTYPE:V)))'
The problem is that there's no case to handle "+XTYPE:H" so the
QueryParser goes into its fallback mode (assuming this is pasted text)
and strips the "+" and "-" signs.

Could you confirm that this patch fixes it:

http://www.oligarchy.co.uk/xapian/patches/queryparser-love-filter.patch

You'll need to apply it in the queryparser subdirectory.

Cheers,
    Olly