Mailing-List: contact lucene-user-help@jakarta.apache.org; run by ezmlm
Precedence: bulk
Reply-To: "Lucene Users List" <lucene-user@jakarta.apache.org>
Received-SPF: pass (hermes.apache.org: local policy)
Mime-Version: 1.0 (Apple Message framework v619)
In-Reply-To: <005b01c4c799$674e1270$32e0fcca@satoshiobtu4n6>
References: <005b01c4c799$674e1270$32e0fcca@satoshiobtu4n6>
Content-Type: text/plain; charset=US-ASCII; format=flowed
Message-Id: <4FF070AE-33C9-11D9-B46A-000393A564E6@ehatchersolutions.com>
Content-Transfer-Encoding: 7bit
From: Erik Hatcher <erik@ehatchersolutions.com>
Subject: Re: Query#rewrite Question
Date: Thu, 11 Nov 2004 05:06:10 -0500
To: "Lucene Users List" <lucene-user@jakarta.apache.org>


On Nov 10, 2004, at 9:51 PM, Satoshi Hasegawa wrote:
> Our program accepts input in the form of Lucene query syntax from the 
> user,
> but we wish to perform additional tasks such as thesaurus expansion. 
> So I
> want to manipulate the Query object that results from parsing.

You may want to consider using an Analyzer to expand queries rather 
than manipulating the query object itself.

> My question is, is the result of the Query#rewrite method guaranteed 
> to be
> either a TermQuery, a PhraseQuery, or a BooleanQuery, and if it is a
> BooleanQuery, do all the constituent clauses also reduce to one of the 
> above
> three classes?

No.  For example, look at the SpanQuery family.  These do no explicit 
rewriting and thus are left as themselves.

>  If not, what if the original Query object was the one that
> was obtained from QueryParser#parse method? Can I assume the above in 
> this
> restricted case?
>
> I experimented with the current version, and the above seems to be 
> positive
> in this version; I'm asking if this could change in the future. Thank 
> you.

I think we'll see QueryParser, or at least more sophisticated versions 
of it, emerge that support SpanQuery's.  In fact, in our book, I 
created a subclas of QueryParser that overrides getFieldQuery and 
returns a SpanNearQuery in order to achieve ordered phrase searching.

	Erik


---------------------------------------------------------------------
To unsubscribe, e-mail: lucene-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: lucene-user-help@jakarta.apache.org