/*
* 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.
*/
package org.apache.lucene.search.spans;
import org.apache.lucene.search.spans.FilterSpans.AcceptStatus;
import java.io.IOException;
/**
* Matches spans near the beginning of a field.
* <p>
* This class is a simple extension of {@link SpanPositionRangeQuery} in that it assumes the
* start to be zero and only checks the end boundary.
*/
public class SpanFirstQuery extends SpanPositionRangeQuery {
/** Construct a SpanFirstQuery matching spans in <code>match</code> whose end
* position is less than or equal to <code>end</code>. */
public SpanFirstQuery(SpanQuery match, int end) {
super(match, 0, end);
}
protected AcceptStatus acceptPosition(Spans spans) throws IOException {
assert spans.startPosition() != spans.endPosition() : "start equals end: " + spans.startPosition();
if (spans.startPosition() >= end)
return AcceptStatus.NO_MORE_IN_CURRENT_DOC;
else if (spans.endPosition() <= end)
return AcceptStatus.YES;
else
return AcceptStatus.NO;
}
@Override
public String toString(String field) {
StringBuilder buffer = new StringBuilder();
buffer.append("spanFirst(");
buffer.append(match.toString(field));
buffer.append(", ");
buffer.append(end);
buffer.append(")");
return buffer.toString();
}
}