Right, and you can simply get an iterator from it. ----- Uwe Schindler H.-H.-Meier-Allee 63, D-28213 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de
> -----Original Message----- > From: Robert Muir [mailto:rcm...@gmail.com] > Sent: Monday, July 27, 2009 12:24 PM > To: java-dev@lucene.apache.org > Subject: Re: svn commit: r798091 - > /lucene/java/trunk/src/java/org/apache/lucene/search/EmptyDocIdSetIterator > .java > > here it is: DocIdSet.EMPTY_DOCIDSET > > /** An empty {...@code DocIdSet} instance for easy use (this is currently > * implemented using a {...@link SortedVIntList}). */ > > On Mon, Jul 27, 2009 at 6:18 AM, Uwe Schindler<u...@thetaphi.de> wrote: > > Why do we need this class? There is already a static final empty > iterator > > available in DocIdSetIterator.EMPTY_DOCIDSET_ITERATOR (or something like > > that name)? > > > > ----- > > Uwe Schindler > > H.-H.-Meier-Allee 63, D-28213 Bremen > > http://www.thetaphi.de > > eMail: u...@thetaphi.de > > > >> From: mikemcc...@apache.org [mailto:mikemcc...@apache.org] > >> Sent: Monday, July 27, 2009 12:03 PM > >> To: java-comm...@lucene.apache.org > >> Subject: svn commit: r798091 - > >> > /lucene/java/trunk/src/java/org/apache/lucene/search/EmptyDocIdSetIterator > >> .java > >> > >> Author: mikemccand > >> Date: Mon Jul 27 10:02:34 2009 > >> New Revision: 798091 > >> > >> URL: http://svn.apache.org/viewvc?rev=798091&view=rev > >> Log: > >> LUCENE-1754: add EmptyDocIdSetIterator > >> > >> Added: > >> > >> > lucene/java/trunk/src/java/org/apache/lucene/search/EmptyDocIdSetIterator. > >> java (with props) > >> > >> Added: > >> > lucene/java/trunk/src/java/org/apache/lucene/search/EmptyDocIdSetIterator. > >> java > >> URL: > >> > http://svn.apache.org/viewvc/lucene/java/trunk/src/java/org/apache/lucene/ > >> search/EmptyDocIdSetIterator.java?rev=798091&view=auto > >> > ========================================================================== > >> ==== > >> --- > >> > lucene/java/trunk/src/java/org/apache/lucene/search/EmptyDocIdSetIterator. > >> java (added) > >> +++ > >> > lucene/java/trunk/src/java/org/apache/lucene/search/EmptyDocIdSetIterator. > >> java Mon Jul 27 10:02:34 2009 > >> @@ -0,0 +1,42 @@ > >> +package org.apache.lucene.search; > >> + > >> +/** > >> + * Licensed to the Apache Software Foundation (ASF) under one or more > >> + * contributor license agreements. See the NOTICE file distributed > with > >> + * this work for additional information regarding copyright ownership. > >> + * The ASF licenses this file to You under the Apache License, Version > >> 2.0 > >> + * (the "License"); you may not use this file except in compliance > with > >> + * the License. You may obtain a copy of the License at > >> + * > >> + * http://www.apache.org/licenses/LICENSE-2.0 > >> + * > >> + * Unless required by applicable law or agreed to in writing, software > >> + * distributed under the License is distributed on an "AS IS" BASIS, > >> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or > >> implied. > >> + * See the License for the specific language governing permissions and > >> + * limitations under the License. > >> + */ > >> + > >> +import java.io.IOException; > >> + > >> +/** > >> + * An empty implementation for {...@link DocIdSetIterator}. This can be > used > >> by > >> + * classes which receive a null {...@link DocIdSet} from > >> + * {...@link Filter#getDocIdSet(org.apache.lucene.index.IndexReader)}. > >> + */ > >> +public final class EmptyDocIdSetIterator extends DocIdSetIterator { > >> + > >> + private static final DocIdSetIterator instance = new > >> EmptyDocIdSetIterator(); > >> + > >> + public static DocIdSetIterator getInstance() { return instance; } > >> + > >> + // to prevent instantiation > >> + private EmptyDocIdSetIterator() { } > >> + > >> + public int advance(int target) throws IOException { return > >> NO_MORE_DOCS; } > >> + > >> + public int docID() { return NO_MORE_DOCS; } > >> + > >> + public int nextDoc() throws IOException { return NO_MORE_DOCS; } > >> + > >> +} > >> > >> Propchange: > >> > lucene/java/trunk/src/java/org/apache/lucene/search/EmptyDocIdSetIterator. > >> java > >> ----------------------------------------------------------------------- > --- > >> ---- > >> svn:eol-style = native > >> > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org > > For additional commands, e-mail: java-dev-h...@lucene.apache.org > > > > > > > > -- > Robert Muir > rcm...@gmail.com > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-dev-h...@lucene.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org For additional commands, e-mail: java-dev-h...@lucene.apache.org
