# Package org.apache.lucene.search.grouping.function

Support for grouping by {org.apache.lucene.queries.function.ValueSource}.

See: Description

Class Summary
Class | Description
--- | ---
FunctionAllGroupHeadsCollector | An implementation of `AbstractAllGroupHeadsCollector` for retrieving the most relevant groups when grouping by `ValueSource`.
FunctionAllGroupsCollector | A collector that collects all groups that match the query.
FunctionDistinctValuesCollector | Function based implementation of `AbstractDistinctValuesCollector`.
FunctionDistinctValuesCollector.GroupCount | Holds distinct values for a single group.
FunctionFirstPassGroupingCollector | Concrete implementation of `AbstractFirstPassGroupingCollector` that groups based on `ValueSource` instances.
FunctionSecondPassGroupingCollector | Concrete implementation of `AbstractSecondPassGroupingCollector` that groups based on `ValueSource` instances.

## Package org.apache.lucene.search.grouping.function Description

Support for grouping by {org.apache.lucene.queries.function.ValueSource}.