TypeTokenFilter in Lucene acts as a blacklist by default, removing some tokens according to their type. It can act as a whitelist if the "useWhitelist" parameter is set to true.

For Elasticsearch analyzers, we translate TypeTokenFilterFactory to Elasticsearch's "keep_types" filter type, and we forbid the use of "useWhitelist". This effectively inverts the meaning of this filter...

What we should do instead is mandate the use of "useWhitelist", and throw an exception when it is either missing or set to something else than "true".

Note: there doesn't seem to be an equivalent to the blacklist mode of TypeTokenFilterFactory in Elasticsearch.