# Package org.eclipse.rdf4j.query.algebra.evaluation.function

- Interface Summary
  Interface | Description
  --- | ---
  Function | A query function, which can be a built-in function in the query language, or a custom function as documented in the SPARQL 1.1 Query Language Recommendation.
  TupleFunction | A function that can return a tuple of `Value`s.

- Class Summary
  Class | Description
  --- | ---
  BinaryFunction |
  BooleanCast | Deprecated. use `BooleanCast` instead
  DateTimeCast | Deprecated. use `DateTimeCast` instead.
  DecimalCast | Deprecated. use `DecimalCast` instead.
  DoubleCast | Deprecated. use `DoubleCast` instead.
  FloatCast | Deprecated. use `FloatCast` instead.
  FunctionRegistry | A ServiceRegistry for implementations of the `Function` interface.
  IntegerCast | Deprecated. use `IntegerCast` instead
  StringCast | Deprecated. use `StringCast` instead
  TupleFunctionRegistry |
  UnaryFunction |