[Xapian-discuss] add_prefix() versus add_boolean_prefix()

Daniel Ménard Daniel.Menard at ehesp.fr
Tue Oct 28 18:27:25 GMT 2008


Hello,

Until now, I was using QueryParser.add_prefix() for all my fields, but I 
realized that some of them were just "filters" and I'm now experimenting 
with add_boolean_prefix() for those fields (I'm using xapian core 1.0.8 
with php bindings 1.0.8).

If I add a boolean prefix 'A' for the field 'author', a request like 
[test author:john author:doe] gives me the following query :
Xapian::Query((test:(pos=1) FILTER (Ajohn OR Adoe)))
which looks good for me.

But if the same request is written like this : [test author:(john doe)], 
I get the following query :
Xapian::Query(((test:(pos=1) OR doe:(pos=2)) FILTER A(john))
which looks strange for me ("doe" is not a filter anymore, extra 
parenthesis before "john").

A similar problem appear if I try a phrase search: [test author:"john 
doe"] gives
Xapian::Query(((test:(pos=1) OR doe:(pos=2)) FILTER A"john))

Is it a bug? (these requests are correctly parsed if add_prefix is used 
instead of add_boolean_prefix).

Thanks!

PS: If it can be useful, here is the php script I used for my tests :

<?php
        require_once('/lib/xapian/xapian.php');
       
        $request='test author:(john doe)';
       
        $parser=new XapianQueryParser();
        $parser->add_prefix('author', 'A');
        echo 'with add_prefix : ', 
$parser->parse_query($request)->get_description(), "\n";
       
        $parser=new XapianQueryParser();
        $parser->add_boolean_prefix('author', 'A');
        echo 'with add_boolean_prefix : ', 
$parser->parse_query($request)->get_description(), "\n";
?>

-- 

Daniel Ménard




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