content: package org.apache.lucene.search.spans;
  
  /**
   * 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 org.apache.lucene.util.ToStringUtils;
  
  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);
    }
  
    @Override
    protected AcceptStatus acceptPosition(Spans spans) throws IOException {
      assert spans.start() != spans.end();
      if (spans.start() >= end)
        return AcceptStatus.NO_AND_ADVANCE;
      else if (spans.end() <= 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(")");
      buffer.append(ToStringUtils.boost(getBoost()));
      return buffer.toString();
    }
  
    @Override
    public Object clone() {
      SpanFirstQuery spanFirstQuery = new SpanFirstQuery((SpanQuery) match.clone(), end);
      spanFirstQuery.setBoost(getBoost());
      return spanFirstQuery;
    }
  
    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (!(o instanceof SpanFirstQuery)) return false;
  
      SpanFirstQuery other = (SpanFirstQuery)o;
      return this.end == other.end
           && this.match.equals(other.match)
           && this.getBoost() == other.getBoost();
    }
  
    @Override
    public int hashCode() {
      int h = match.hashCode();
      h ^= (h << 8) | (h >>> 25);  // reversible
      h ^= Float.floatToRawIntBits(getBoost()) ^ end;
      return h;
    }
  
  
  }
  