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SpanOrQuery.javaAPI DocApache Lucene 1.4.35654Mon Feb 09 22:03:42 GMT 2004org.apache.lucene.search.spans

SpanOrQuery

public class SpanOrQuery extends SpanQuery
Matches the union of its clauses.

Fields Summary
private List
clauses
private String
field
Constructors Summary
public SpanOrQuery(SpanQuery[] clauses)
Construct a SpanOrQuery merging the provided clauses.


    // copy clauses array into an ArrayList
    this.clauses = new ArrayList(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);
    }
Methods Summary
public org.apache.lucene.search.spans.SpanQuery[]getClauses()
Return the clauses whose spans are matched.

    return (SpanQuery[])clauses.toArray(new SpanQuery[clauses.size()]);
public java.lang.StringgetField()

 return field;
public org.apache.lucene.search.spans.SpansgetSpans(org.apache.lucene.index.IndexReader reader)

    if (clauses.size() == 1)                      // optimize 1-clause case
      return ((SpanQuery)clauses.get(0)).getSpans(reader);

    return new Spans() {
        private List all = new ArrayList(clauses.size());
        private SpanQueue queue = new SpanQueue(clauses.size());

        {
          Iterator i = clauses.iterator();
          while (i.hasNext()) {                   // initialize all
            all.add(((SpanQuery)i.next()).getSpans(reader));
          }
        }

        private boolean firstTime = true;

        public boolean next() throws IOException {
          if (firstTime) {                        // first time -- initialize
            for (int i = 0; i < all.size(); i++) {
              Spans spans = (Spans)all.get(i);
              if (spans.next()) {                 // move to first entry
                queue.put(spans);                 // build queue
              } else {
                all.remove(i--);
              }
            }
            firstTime = false;
            return queue.size() != 0;
          }

          if (queue.size() == 0) {                // all done
            return false;
          }

          if (top().next()) {                     // move to next
            queue.adjustTop();
            return true;
          }

          all.remove(queue.pop());                // exhausted a clause

          return queue.size() != 0;
        }

        private Spans top() { return (Spans)queue.top(); }

        public boolean skipTo(int target) throws IOException {
          if (firstTime) {
            for (int i = 0; i < all.size(); i++) {
              Spans spans = (Spans)all.get(i);
              if (spans.skipTo(target)) {         // skip each spans in all
                queue.put(spans);                 // build queue
              } else {
                all.remove(i--);
              }
            }
            firstTime = false;
          } else {
            while (queue.size() != 0 && top().doc() < target) {
              if (top().skipTo(target)) {
                queue.adjustTop();
              } else {
                all.remove(queue.pop());
              }
            }
          }

          return queue.size() != 0;
        }

        public int doc() { return top().doc(); }
        public int start() { return top().start(); }
        public int end() { return top().end(); }

        public String toString() {
          return "spans("+SpanOrQuery.this+")@"+
            (firstTime?"START"
             :(queue.size()>0?(doc()+":"+start()+"-"+end()):"END"));
        }

      };
public java.util.CollectiongetTerms()

    Collection terms = new ArrayList();
    Iterator i = clauses.iterator();
    while (i.hasNext()) {
      SpanQuery clause = (SpanQuery)i.next();
      terms.addAll(clause.getTerms());
    }
    return terms;
public java.lang.StringtoString(java.lang.String field)

    StringBuffer buffer = new StringBuffer();
    buffer.append("spanOr([");
    Iterator i = clauses.iterator();
    while (i.hasNext()) {
      SpanQuery clause = (SpanQuery)i.next();
      buffer.append(clause.toString(field));
      if (i.hasNext()) {
        buffer.append(", ");
      }
    }
    buffer.append("])");
    return buffer.toString();