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Date: Mon, 7 Jun 2010 22:25:51 -0700
Message-ID: <AANLkTinIHwqvxv-Jy7G-4nm0umXuBLCHSQ3Z-bH7jQgC@mail.gmail.com>
Subject: Proposal: Scorer api change
From: John Wang <john.wang@gmail.com>
To: dev@lucene.apache.org
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Hi guys:

    I'd like to make a proposal to change the Scorer class/api to the
following:


public abstract class Scorer{
   DocIdSetIterator getDocIDSetIterator();
   float score(int docid);
}

Reasons:

1) To build a Scorer from an existing Scorer (e.g. that produces raw scores
from tfidf), one would decorate it, and it would introduce overhead (in
function calls) around nextDoc and advance, even if you just want to augment
the score method which is called much fewer times.

2) The current contract forces scoring on the currentDoc in the underlying
iterator. So once you pass "current", you can no longer score. In one of our
use-cases, it is very inconvenient.

What do you think? I can go ahead and open an issue and work on a patch if I
get some agreement.

Thanks

-John

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Hi guys:<br><br>=A0=A0=A0 I&#39;d like to make a proposal to change the Sco=
rer class/api to the following:<br><br><br>public abstract class Scorer{<br=
>=A0=A0 DocIdSetIterator getDocIDSetIterator();<br>=A0=A0 float score(int d=
ocid);<br>}<br>
<br>Reasons:<br><br>1) To build a Scorer from an existing Scorer (e.g. that=
 produces raw scores from tfidf), one would decorate it, and it would intro=
duce overhead (in function calls) around nextDoc and advance, even if you j=
ust want to augment the score method which is called much fewer times.<br>
<br>2) The current contract forces scoring on the currentDoc in the underly=
ing iterator. So once you pass &quot;current&quot;, you can no longer score=
. In one of our use-cases, it is very inconvenient.<br><br>What do you thin=
k? I can go ahead and open an issue and work on a patch if I get some agree=
ment.<br>
<br>Thanks<br><br>-John<br>

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