# All Classes and Interfaces

Class
Description
AveragePayloadFunction
Calculate the final score as the average score of all payloads seen.
BoolDocValues
Abstract `FunctionValues` implementation which supports retrieving boolean values.
BoolFunction
Abstract parent class for those `ValueSource` implementations which apply boolean logic to their values
ByteKnnVectorFieldSource
An implementation for retrieving `FunctionValues` instances for byte knn vectors fields.
BytesRefFieldSource
An implementation for retrieving `FunctionValues` instances for string based fields.
ByteVectorSimilarityFunction
`ByteVectorSimilarityFunction` returns a similarity function between two knn vectors with byte elements.
CommonTermsQuery
A query that executes high-frequency terms in a optional sub-query to prevent slow queries due to "common" terms like stopwords.
ComparisonBoolFunction
Base class for comparison operators useful within an "if"/conditional.
ConstKnnByteVectorValueSource
Function that returns a constant byte vector value for every document.
ConstKnnFloatValueSource
Function that returns a constant float vector value for every document.
ConstNumberSource
`ConstNumberSource` is the base class for all constant numbers
ConstValueSource
`ConstValueSource` returns a constant for all documents
DefFunction
`ValueSource` implementation which only returns the values from the provided ValueSources which are available for a particular docId.
DivFloatFunction
Function to divide "a" by "b"
DocFreqValueSource
`DocFreqValueSource` returns the number of documents containing the term.
DocTermsIndexDocValues
Serves as base class for FunctionValues based on DocTermsIndex.
DocTermsIndexDocValues.DocTermsIndexException
Custom Exception to be thrown when the DocTermsIndex for a field cannot be generated
DoubleConstValueSource
Function that returns a constant double value for every document.
DoubleDocValues
Abstract `FunctionValues` implementation which supports retrieving double values.
DoubleFieldSource
Obtains double field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
DualFloatFunction
Abstract `ValueSource` implementation which wraps two ValueSources and applies an extendible float function to their values.
EnumFieldSource
Obtains int field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
FieldCacheSource
A base class for ValueSource implementations that retrieve values for a single field from DocValues.
FieldMaskingSpanQuery
Wrapper to allow `SpanQuery` objects participate in composite single-field SpanQueries by 'lying' about their search field.
FilteredIntervalsSource
An IntervalsSource that filters the intervals from another IntervalsSource
FilterSpans
A `Spans` implementation wrapping another spans instance, allowing to filter spans matches easily by implementing `FilterSpans.accept(org.apache.lucene.queries.spans.Spans)`
FilterSpans.AcceptStatus
Status returned from `FilterSpans.accept(Spans)` that indicates whether a candidate match should be accepted, rejected, or rejected and move on to the next document.
FloatDocValues
Abstract `FunctionValues` implementation which supports retrieving float values.
FloatFieldSource
Obtains float field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
FloatKnnVectorFieldSource
An implementation for retrieving `FunctionValues` instances for float knn vectors fields.
FloatVectorSimilarityFunction
`FloatVectorSimilarityFunction` returns a similarity function between two knn vectors with float elements.
FunctionMatchQuery
A query that retrieves all documents with a `DoubleValues` value matching a predicate
FunctionQuery
Returns a score for each document based on a ValueSource, often some function of the value of a field.
FunctionRangeQuery
A Query wrapping a `ValueSource` that matches docs in which the values in the value source match a configured range.
FunctionScoreQuery
A query that wraps another query, and uses a DoubleValuesSource to replace or modify the wrapped query's score
FunctionValues
Represents field values as different types.
FunctionValues.ValueFiller
Abstraction of the logic required to fill the value of a specified doc into a reusable `MutableValue`.
IDFValueSource
Function that returns `#idf(long, long)` for every document.
IfFunction
Depending on the boolean value of the `ifSource` function, returns the value of the `trueSource` or `falseSource` function.
IndexReaderFunctions
Class exposing static helper methods for generating DoubleValuesSource instances over some IndexReader statistics
IntDocValues
Abstract `FunctionValues` implementation which supports retrieving int values.
IntervalFilter
Wraps an `IntervalIterator` and passes through those intervals that match the `IntervalFilter.accept()` function
IntervalIterator
A `DocIdSetIterator` that also allows iteration over matching intervals in a document.
IntervalMatchesIterator
An extension of MatchesIterator that allows it to be treated as an IntervalIterator
IntervalQuery
A query that retrieves documents containing intervals returned from an `IntervalsSource`
Intervals
Factory functions for creating `interval sources`.
IntervalsSource
A helper class for `IntervalQuery` that provides an `IntervalIterator` for a given field and segment
IntFieldSource
Obtains int field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
JoinDocFreqValueSource
Use a field value and find the Document Frequency within another field.
LinearFloatFunction
`LinearFloatFunction` implements a linear function over another `ValueSource`.
LiteralValueSource
Pass a the field value through as a String, no matter the type // Q: doesn't this mean it's a "string"?
LongDocValues
Abstract `FunctionValues` implementation which supports retrieving long values.
LongFieldSource
Obtains long field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
MaxDocValueSource
Returns the value of `IndexReader.maxDoc()` for every document.
MaxFloatFunction
`MaxFloatFunction` returns the max of its components.
MaxPayloadFunction
Returns the maximum payload score seen, else 1 if there are no payloads on the doc.
MinFloatFunction
`MinFloatFunction` returns the min of its components.
MinPayloadFunction
Calculates the minimum payload seen
MoreLikeThis
Generate "more like this" similarity queries.
MoreLikeThisQuery
A simple wrapper for MoreLikeThis for use in scenarios where a Query object is required eg in custom QueryParser extensions.
MultiBoolFunction
Abstract `ValueSource` implementation which wraps multiple ValueSources and applies an extendible boolean function to their values.
MultiFloatFunction
Abstract `ValueSource` implementation which wraps multiple ValueSources and applies an extendible float function to their values.
MultiFunction
Abstract parent class for `ValueSource` implementations that wrap multiple ValueSources and apply their own logic.
MultiValuedDoubleFieldSource
Obtains double field values from `LeafReader.getSortedNumericDocValues(java.lang.String)` and using a `SortedNumericSelector` it gives a single-valued ValueSource view of a field.
MultiValuedFloatFieldSource
Obtains float field values from `LeafReader.getSortedNumericDocValues(java.lang.String)` and using a `SortedNumericSelector` it gives a single-valued ValueSource view of a field.
MultiValuedIntFieldSource
Obtains int field values from `LeafReader.getSortedNumericDocValues(java.lang.String)` and using a `SortedNumericSelector` it gives a single-valued ValueSource view of a field.
MultiValuedLongFieldSource
Obtains long field values from `LeafReader.getSortedNumericDocValues(java.lang.String)` and using a `SortedNumericSelector` it gives a single-valued ValueSource view of a field.
MultiValueSource
A `ValueSource` that abstractly represents `ValueSource`s for poly fields, and other things.
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.
NormValueSource
Function that returns the decoded norm for every document.
NumDocsValueSource
Returns the value of `IndexReader.numDocs()` for every document.
PayloadDecoder
Defines a way of converting payloads to float values, for use by `PayloadScoreQuery`
PayloadFunction
An abstract class that defines a way for PayloadScoreQuery instances to transform the cumulative effects of payload scores for a document.
PayloadMatcher
Defines an interface for testing if two payloads should be consider to match
PayloadMatcherFactory
Creates a payload matcher object based on a payload type and an operation.
PayloadScoreQuery
A Query class that uses a `PayloadFunction` to modify the score of a wrapped `SpanQuery`.
PowFloatFunction
Function to raise the base "a" to the power "b"
ProductFloatFunction
`ProductFloatFunction` returns the product of its components.
QueryValueSource
`QueryValueSource` returns the relevance score of the query
RangeMapFloatFunction
`RangeMapFloatFunction` implements a map function over another `ValueSource` whose values fall within min and max inclusive to target.
ReciprocalFloatFunction
`ReciprocalFloatFunction` implements a reciprocal function f(x) = a/(mx+b), based on the float value of a field or function as exported by `ValueSource`.
ScaleFloatFunction
Scales values to be between min and max.
SimpleBoolFunction
`BoolFunction` implementation which applies an extendible boolean function to the values of a single wrapped `ValueSource`.
SimpleFloatFunction
A simple float function with a single argument
SingleFunction
A function with a single argument
SortedSetFieldSource
Retrieves `FunctionValues` instances for multi-valued string based fields.
SpanCollector
An interface defining the collection of postings information from the leaves of a `Spans`
SpanContainingQuery
Keep matches that contain another SpanScorer.
SpanDisiWrapper
Wrapper used in `SpanDisiPriorityQueue`.
SpanFirstQuery
Matches spans near the beginning of a field.
SpanMultiTermQueryWrapper<Q>
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.
SpanNearQuery
Matches spans which are near one another.
SpanNearQuery.Builder
A builder for SpanNearQueries
SpanNotQuery
Removes matches which overlap with another SpanQuery or which are within 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.
SpanPayloadCheckQuery.MatchOperation
The payload type.
SpanPayloadCheckQuery.PayloadType
The payload type.
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
Iterates through combinations of start/end positions per-doc.
SpanScorer
A basic `Scorer` over `Spans`.
SpanTermQuery
Matches spans containing a term.
SpanWeight
Expert-only.
SpanWeight.Postings
Enumeration defining what postings information should be retrieved from the index for a given Spans
SpanWithinQuery
Keep matches that are contained within another Spans.
StrDocValues
Abstract `FunctionValues` implementation which supports retrieving String values.
SumFloatFunction
`SumFloatFunction` returns the sum of its components.
SumPayloadFunction
Calculate the final score as the sum of scores of all payloads seen.
SumTotalTermFreqValueSource
`SumTotalTermFreqValueSource` returns the number of tokens.
TermFreqValueSource
Function that returns `PostingsEnum.freq()` for the supplied term in every document.
TermSpans
Expert: Public for extension only.
TFValueSource
Function that returns `TFIDFSimilarity.tf(float)` for every document.
TotalTermFreqValueSource
`TotalTermFreqValueSource` returns the total term freq (sum of term freqs across all documents).
ValueSource
Instantiates `FunctionValues` for a particular reader.
ValueSourceScorer
`Scorer` which returns the result of `FunctionValues.floatVal(int)` as the score for a document, and which filters out documents that don't match `ValueSourceScorer.matches(int)`.
VectorFieldFunction
An implementation for retrieving `FunctionValues` instances for knn vectors fields.
VectorSimilarityFunction
`VectorSimilarityFunction` returns a similarity function between two knn vectors.
VectorValueSource
Converts individual ValueSource instances to leverage the FunctionValues *Val functions that work with multiple values, i.e.