# Uses of Package
org.apache.lucene.queries.function.valuesource

- Packages that use org.apache.lucene.queries.function.valuesource
  Package | Description
  --- | ---
  org.apache.lucene.queries.function.valuesource | A variety of functions to use with FunctionQuery.

- Classes in org.apache.lucene.queries.function.valuesource used by org.apache.lucene.queries.function.valuesource
  Class | Description
  --- | ---
  BoolFunction | Abstract parent class for those `ValueSource` implementations which apply boolean logic to their values
  ConstNumberSource | `ConstNumberSource` is the base class for all constant numbers
  DocFreqValueSource | `DocFreqValueSource` returns the number of documents containing the term.
  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.
  FieldCacheSource | A base class for ValueSource implementations that retrieve values for a single field from DocValues.
  FloatFieldSource | Obtains float field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
  IntFieldSource | Obtains int field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
  LongFieldSource | Obtains long field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
  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.
  MultiValueSource | A `ValueSource` that abstractly represents `ValueSource`s for poly fields, and other things.
  SingleFunction | A function with a single argument
  TermFreqValueSource | Function that returns `PostingsEnum.freq()` for the supplied term in every document.
  VectorSimilarityFunction | `VectorSimilarityFunction` returns a similarity function between two knn vectors.