## Package org.apache.lucene.facet.index.categorypolicy

Policies for indexing categories

See:
Description

Interface Summary
OrdinalPolicy: Filtering category ordinals in `CategoryParentsStream`, where a given category ordinal is added to the stream, and than its parents are being added one after the other using `TaxonomyWriter.getParent(int)`.
PathPolicy: Filtering category paths in `CategoryParentsStream`, where a given category is added to the stream, and than all its parents are being added one after the other by successively removing the last component.

Class Summary
DefaultOrdinalPolicy: This class filters our the ROOT category ID.
DefaultPathPolicy: This class filters our the ROOT category path.
NonTopLevelOrdinalPolicy: Filter out any "top level" category ordinals.
NonTopLevelPathPolicy: This class filters our the ROOT category, and it's direct descendants.

## Package org.apache.lucene.facet.index.categorypolicy Description

# Policies for indexing categories

There are two kinds of policies:

- Path policies are based on the path of the category.
- Ordinal policies are based on the ordinal of the category.

Policies are "consulted" with during indexing, for deciding whether a category should be added to the index or not. The two kinds of policies can be used for different purposes. For example, path policies dictates which categories can participate in a drill-down operation, while ordinal policies affect which can be accumulated (e.g. counted).