Package org.apache.lucene.search
Class Scorer
java.lang.Object
org.apache.lucene.search.DocIdSetIterator
org.apache.lucene.index.DocsEnum
org.apache.lucene.search.Scorer
- Direct Known Subclasses:
ConstantScoreQuery.ConstantScorer
,ScoreCachingWrappingScorer
,SpanScorer
Expert: Common scoring functionality for different types of queries.
A Scorer
iterates over documents matching a
query in increasing order of doc Id.
Document scores are computed using a given Similarity
implementation.
NOTE: The values Float.Nan,
Float.NEGATIVE_INFINITY and Float.POSITIVE_INFINITY are
not valid scores. Certain collectors (eg TopScoreDocCollector
) will not properly collect hits
with these scores.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic class
A child Scorer and its relationship to its parent. -
Field Summary
FieldsFields inherited from class org.apache.lucene.index.DocsEnum
FLAG_FREQS, FLAG_NONE
Fields inherited from class org.apache.lucene.search.DocIdSetIterator
NO_MORE_DOCS
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionReturns child sub-scorersreturns parent Weightabstract float
score()
Returns the score of the current document matching the query.void
Scores and collects all matching documents.boolean
Expert: Collects matching documents in a range.Methods inherited from class org.apache.lucene.index.DocsEnum
attributes, freq
Methods inherited from class org.apache.lucene.search.DocIdSetIterator
advance, cost, docID, empty, nextDoc, slowAdvance
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Field Details
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weight
the Scorer's parent Weight. in some cases this may be null
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Constructor Details
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Scorer
Constructs a Scorer- Parameters:
weight
- The scorersWeight
.
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Method Details
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score
Scores and collects all matching documents.- Parameters:
collector
- The collector to which all matching documents are passed.- Throws:
IOException
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score
Expert: Collects matching documents in a range. Hook for optimization. Note,firstDocID
is added to ensure thatDocIdSetIterator.nextDoc()
was called before this method.- Parameters:
collector
- The collector to which all matching documents are passed.max
- Do not score documents past this.firstDocID
- The first document ID (ensuresDocIdSetIterator.nextDoc()
is called before this method.- Returns:
- true if more matching documents may remain.
- Throws:
IOException
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score
Returns the score of the current document matching the query. Initially invalid, untilDocIdSetIterator.nextDoc()
orDocIdSetIterator.advance(int)
is called the first time, or when called from withinCollector.collect(int)
.- Throws:
IOException
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getWeight
returns parent Weight -
getChildren
Returns child sub-scorers
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