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 java.io.IOException;
  
  
  import java.util.List;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.Set;
  
  
  import org.apache.lucene.index.IndexReader;
  import org.apache.lucene.index.Term;
  import org.apache.lucene.search.Query;
  import org.apache.lucene.util.ToStringUtils;
  
  /** Matches spans which are near one another.  One can specify <i>slop</i>, the
   * maximum number of intervening unmatched positions, as well as whether
   * matches are required to be in-order. */
  public class SpanNearQuery extends SpanQuery implements Cloneable {
    protected List<SpanQuery> clauses;
    protected int slop;
    protected boolean inOrder;
  
    protected String field;
    private boolean collectPayloads;
  
    /** Construct a SpanNearQuery.  Matches spans matching a span from each
     * clause, with up to <code>slop</code> total unmatched positions between
     * them.  * When <code>inOrder</code> is true, the spans from each clause
     * must be * ordered as in <code>clauses</code>.
     * @param clauses the clauses to find near each other
     * @param slop The slop value
     * @param inOrder true if order is important
     * */
    public SpanNearQuery(SpanQuery[] clauses, int slop, boolean inOrder) {
      this(clauses, slop, inOrder, true);     
    }
    
    public SpanNearQuery(SpanQuery[] clauses, int slop, boolean inOrder, boolean collectPayloads) {
  
      // copy clauses array into an ArrayList
      this.clauses = new ArrayList<SpanQuery>(clauses.length);
      for (int i = 0; i < clauses.length; i++) {
        SpanQuery clause = clauses[i];
        if (i == 0) {                               // check field
          field = clause.getField();
        } else if (!clause.getField().equals(field)) {
          throw new IllegalArgumentException("Clauses must have same field.");
        }
        this.clauses.add(clause);
      }
      this.collectPayloads = collectPayloads;
      this.slop = slop;
      this.inOrder = inOrder;
    }
  
    /** Return the clauses whose spans are matched. */
    public SpanQuery[] getClauses() {
      return clauses.toArray(new SpanQuery[clauses.size()]);
    }
  
    /** Return the maximum number of intervening unmatched positions permitted.*/
    public int getSlop() { return slop; }
  
    /** Return true if matches are required to be in-order.*/
    public boolean isInOrder() { return inOrder; }
  
    @Override
    public String getField() { return field; }
    
    @Override
    public void extractTerms(Set<Term> terms) {
  	    for (final SpanQuery clause : clauses) {
  	      clause.extractTerms(terms);
  	    }
    }  
    
  
    @Override
    public String toString(String field) {
      StringBuilder buffer = new StringBuilder();
      buffer.append("spanNear([");
      Iterator<SpanQuery> i = clauses.iterator();
      while (i.hasNext()) {
        SpanQuery clause = i.next();
        buffer.append(clause.toString(field));
        if (i.hasNext()) {
          buffer.append(", ");
        }
      }
      buffer.append("], ");
      buffer.append(slop);
      buffer.append(", ");
      buffer.append(inOrder);
      buffer.append(")");
      buffer.append(ToStringUtils.boost(getBoost()));
      return buffer.toString();
    }
  
    @Override
    public Spans getSpans(final IndexReader reader) throws IOException {
      if (clauses.size() == 0)                      // optimize 0-clause case
        return new SpanOrQuery(getClauses()).getSpans(reader);
  
      if (clauses.size() == 1)                      // optimize 1-clause case
        return clauses.get(0).getSpans(reader);
  
      return inOrder
              ? (Spans) new NearSpansOrdered(this, reader, collectPayloads)
              : (Spans) new NearSpansUnordered(this, reader);
    }
  
    @Override
    public Query rewrite(IndexReader reader) throws IOException {
      SpanNearQuery clone = null;
      for (int i = 0 ; i < clauses.size(); i++) {
        SpanQuery c = clauses.get(i);
        SpanQuery query = (SpanQuery) c.rewrite(reader);
        if (query != c) {                     // clause rewrote: must clone
          if (clone == null)
            clone = (SpanNearQuery) this.clone();
          clone.clauses.set(i,query);
        }
      }
      if (clone != null) {
        return clone;                        // some clauses rewrote
      } else {
        return this;                         // no clauses rewrote
      }
    }
    
    @Override
    public Object clone() {
      int sz = clauses.size();
      SpanQuery[] newClauses = new SpanQuery[sz];
  
      for (int i = 0; i < sz; i++) {
        newClauses[i] = (SpanQuery) clauses.get(i).clone();
      }
      SpanNearQuery spanNearQuery = new SpanNearQuery(newClauses, slop, inOrder);
      spanNearQuery.setBoost(getBoost());
      return spanNearQuery;
    }
  
    /** Returns true iff <code>o</code> is equal to this. */
    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (!(o instanceof SpanNearQuery)) return false;
  
      final SpanNearQuery spanNearQuery = (SpanNearQuery) o;
  
      if (inOrder != spanNearQuery.inOrder) return false;
      if (slop != spanNearQuery.slop) return false;
      if (!clauses.equals(spanNearQuery.clauses)) return false;
  
      return getBoost() == spanNearQuery.getBoost();
    }
  
    @Override
    public int hashCode() {
      int result;
      result = clauses.hashCode();
      // Mix bits before folding in things like boost, since it could cancel the
      // last element of clauses.  This particular mix also serves to
      // differentiate SpanNearQuery hashcodes from others.
      result ^= (result << 14) | (result >>> 19);  // reversible
      result += Float.floatToRawIntBits(getBoost());
      result += slop;
      result ^= (inOrder ? 0x99AFD3BD : 0);
      return result;
    }
  }
  