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package org.apache.lucene.search;
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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import java.io.IOException;
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* This abstract class defines methods to iterate over a set of non-decreasing
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* doc ids. Note that this class assumes it iterates on doc Ids, and therefore
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* {@link #NO_MORE_DOCS} is set to {@value #NO_MORE_DOCS} in order to be used as
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* a sentinel object. Implementations of this class are expected to consider
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* {@link Integer#MAX_VALUE} as an invalid value.
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public abstract class DocIdSetIterator {
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* When returned by {@link #nextDoc()}, {@link #advance(int)} and
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* {@link #docID()} it means there are no more docs in the iterator.
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public static final int NO_MORE_DOCS = Integer.MAX_VALUE;
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* Returns the following:
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* <li>-1 or {@link #NO_MORE_DOCS} if {@link #nextDoc()} or
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* {@link #advance(int)} were not called yet.
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* <li>{@link #NO_MORE_DOCS} if the iterator has exhausted.
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* <li>Otherwise it should return the doc ID it is currently on.
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public abstract int docID();
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* Advances to the next document in the set and returns the doc it is
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* currently on, or {@link #NO_MORE_DOCS} if there are no more docs in the
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* <b>NOTE:</b> after the iterator has exhausted you should not call this
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* method, as it may result in unpredicted behavior.
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public abstract int nextDoc() throws IOException;
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* Advances to the first beyond (see NOTE below) the current whose document
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* number is greater than or equal to <i>target</i>. Returns the current
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* document number or {@link #NO_MORE_DOCS} if there are no more docs in the
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* Behaves as if written:
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* int advance(int target) {
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* while ((doc = nextDoc()) < target) {
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* Some implementations are considerably more efficient than that.
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* <b>NOTE:</b> when <code> target ≤ current</code> implementations may opt
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* not to advance beyond their current {@link #docID()}.
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* <b>NOTE:</b> this method may be called with {@link #NO_MORE_DOCS} for
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* efficiency by some Scorers. If your implementation cannot efficiently
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* determine that it should exhaust, it is recommended that you check for that
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* value in each call to this method.
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* <b>NOTE:</b> after the iterator has exhausted you should not call this
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* method, as it may result in unpredicted behavior.
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public abstract int advance(int target) throws IOException;