Dynamically computed values to sort/facet/search on based on a pluggable grammar.
'org.apache.lucene:lucene-expressions:4.7.2'
<dependency>
<groupId>org.apache.lucene</groupId>
<artifactId>lucene-expressions</artifactId>
<version>4.7.2</version>
</dependency>
<dependency org="org.apache.lucene" name="lucene-expressions" rev="4.7.2"/>
"org.apache.lucene", "lucene-expressions", "4.7.2"