Package org.apache.lucene.search.spans

The calculus of spans.

See:
          Description

Class Summary
FieldMaskingSpanQuery Wrapper to allow SpanQuery objects participate in composite single-field SpanQueries by 'lying' about their search field.
NearSpansOrdered A Spans that is formed from the ordered subspans of a SpanNearQuery where the subspans do not overlap and have a maximum slop between them.
NearSpansUnordered Similar to NearSpansOrdered, but for the unordered case.
SpanFirstQuery Matches spans near the beginning of a field.
SpanMultiTermQueryWrapper<Q extends MultiTermQuery> Wraps any MultiTermQuery as a SpanQuery, so it can be nested within other SpanQuery classes.
SpanMultiTermQueryWrapper.SpanRewriteMethod Abstract class that defines how the query is rewritten.
SpanMultiTermQueryWrapper.TopTermsSpanBooleanQueryRewrite A rewrite method that first translates each term into a SpanTermQuery in a BooleanClause.Occur.SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query.
SpanNearPayloadCheckQuery Only return those matches that have a specific payload at the given position.
SpanNearQuery Matches spans which are near one another.
SpanNotQuery Removes matches which overlap with another SpanQuery or within a x tokens before or y tokens after another SpanQuery.
SpanOrQuery Matches the union of its clauses.
SpanPayloadCheckQuery Only return those matches that have a specific payload at the given position.
SpanPositionCheckQuery Base class for filtering a SpanQuery based on the position of a match.
SpanPositionRangeQuery Checks to see if the SpanPositionCheckQuery.getMatch() lies between a start and end position
SpanQuery Base class for span-based queries.
Spans Expert: an enumeration of span matches.
SpanScorer Public for extension only.
SpanTermQuery Matches spans containing a term.
SpanWeight Expert-only.
TermSpans Expert: Public for extension only
 

Enum Summary
SpanPositionCheckQuery.AcceptStatus Return value for SpanPositionCheckQuery.acceptPosition(Spans).
 

Package org.apache.lucene.search.spans Description

The calculus of spans.

A span is a <doc,startPosition,endPosition> tuple.

The following span query operators are implemented:

In all cases, output spans are minimally inclusive. In other words, a span formed by matching a span in x and y starts at the lesser of the two starts and ends at the greater of the two ends.

For example, a span query which matches "John Kerry" within ten words of "George Bush" within the first 100 words of the document could be constructed with:

SpanQuery john   = new SpanTermQuery(new Term("content", "john"));
SpanQuery kerry  = new SpanTermQuery(new Term("content", "kerry"));
SpanQuery george = new SpanTermQuery(new Term("content", "george"));
SpanQuery bush   = new SpanTermQuery(new Term("content", "bush"));

SpanQuery johnKerry =
   new SpanNearQuery(new SpanQuery[] {john, kerry}, 0, true);

SpanQuery georgeBush =
   new SpanNearQuery(new SpanQuery[] {george, bush}, 0, true);

SpanQuery johnKerryNearGeorgeBush =
   new SpanNearQuery(new SpanQuery[] {johnKerry, georgeBush}, 10, false);

SpanQuery johnKerryNearGeorgeBushAtStart =
   new SpanFirstQuery(johnKerryNearGeorgeBush, 100);

Span queries may be freely intermixed with other Lucene queries. So, for example, the above query can be restricted to documents which also use the word "iraq" with:

Query query = new BooleanQuery();
query.add(johnKerryNearGeorgeBushAtStart, true, false);
query.add(new TermQuery("content", "iraq"), true, false);



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