# Package org.apache.lucene.analysis.snowball

`TokenFilter` and `Analyzer` implementations that use a modified version of Snowball stemmers. See Snowball project page for more information about the original algorithms used.

Lucene snowball classes require a few patches to the original Snowball source tree to generate more efficient code.

Refer to `gradle/generation/snowball*` and `help/regeneration.txt` files in Lucene source code for instructions on how code regeneration from Snowball sources works, what modifications are applied and what is required to regenerate snowball analyzers from scratch.

IMPORTANT NOTICE ON BACKWARDS COMPATIBILITY!

An index created using the Snowball module in one Lucene version may not be compatible with an index created with another Lucene version. The token stream will vary depending on the changes in snowball stemmer definitions.

- Class Summary
  Class | Description
  --- | ---
  SnowballFilter | A filter that stems words using a Snowball-generated stemmer.
  SnowballPorterFilterFactory | Factory for `SnowballFilter`, with configurable language