FileDocCategorySizeDatePackage
SpanNotQuery.javaAPI DocApache Lucene 1.4.34710Mon Feb 02 13:27:52 GMT 2004org.apache.lucene.search.spans

SpanNotQuery

public class SpanNotQuery extends SpanQuery
Removes matches which overlap with another SpanQuery.

Fields Summary
private SpanQuery
include
private SpanQuery
exclude
Constructors Summary
public SpanNotQuery(SpanQuery include, SpanQuery exclude)
Construct a SpanNotQuery matching spans from include which have no overlap with spans from exclude.

    this.include = include;
    this.exclude = exclude;

    if (!include.getField().equals(exclude.getField()))
      throw new IllegalArgumentException("Clauses must have same field.");
Methods Summary
public org.apache.lucene.search.spans.SpanQuerygetExclude()
Return the SpanQuery whose matches must not overlap those returned.

 return exclude;
public java.lang.StringgetField()

 return include.getField();
public org.apache.lucene.search.spans.SpanQuerygetInclude()
Return the SpanQuery whose matches are filtered.

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

    return new Spans() {
        private Spans includeSpans = include.getSpans(reader);
        private boolean moreInclude = true;

        private Spans excludeSpans = exclude.getSpans(reader);
        private boolean moreExclude = true;

        public boolean next() throws IOException {
          if (moreInclude)                        // move to next include
            moreInclude = includeSpans.next();

          while (moreInclude && moreExclude) {

            if (includeSpans.doc() > excludeSpans.doc()) // skip exclude
              moreExclude = excludeSpans.skipTo(includeSpans.doc());

            while (moreExclude                    // while exclude is before
                   && includeSpans.doc() == excludeSpans.doc()
                   && excludeSpans.end() <= includeSpans.start()) {
              moreExclude = excludeSpans.next();  // increment exclude
            }

            if (!moreExclude                      // if no intersection
                || includeSpans.doc() != excludeSpans.doc()
                || includeSpans.end() <= excludeSpans.start())
              break;                              // we found a match

            moreInclude = includeSpans.next();    // intersected: keep scanning
          }
          return moreInclude;
        }

        public boolean skipTo(int target) throws IOException {
          if (moreInclude)                        // skip include
            moreInclude = includeSpans.skipTo(target);

          if (!moreInclude)
            return false;

          if (moreExclude                         // skip exclude
              && includeSpans.doc() > excludeSpans.doc())
            moreExclude = excludeSpans.skipTo(includeSpans.doc());

          while (moreExclude                      // while exclude is before
                 && includeSpans.doc() == excludeSpans.doc()
                 && excludeSpans.end() <= includeSpans.start()) {
            moreExclude = excludeSpans.next();    // increment exclude
          }

          if (!moreExclude                      // if no intersection
                || includeSpans.doc() != excludeSpans.doc()
                || includeSpans.end() <= excludeSpans.start())
            return true;                          // we found a match

          return next();                          // scan to next match
        }

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

        public String toString() {
          return "spans(" + SpanNotQuery.this.toString() + ")";
        }

      };
public java.util.CollectiongetTerms()

 return include.getTerms();
public java.lang.StringtoString(java.lang.String field)

    StringBuffer buffer = new StringBuffer();
    buffer.append("spanNot(");
    buffer.append(include.toString(field));
    buffer.append(", ");
    buffer.append(exclude.toString(field));
    buffer.append(")");
    return buffer.toString();