elasticsearch/elasticsearch — pull request #7120 by rmuir (2014-08-01 09:30:04+00:00)
Title: Add keep_types for filtering by token type

For example, you can use this combined with UAXURLTokenizer to extract urls from text.

This patch works, but I am unsure about the naming of the filter and the parameters.
In fact this filter in lucene supports two modes "stop" and "keep".