The expressions module is new to Lucene 4.6. It provides an API for dynamically computing per-document values based on string expressions.
The module is organized in two sections: 1. xref:Lucene.Net.Expressions - The abstractions and simple utilities for common operations like sorting on an expression 2. xref:Lucene.Net.Expressions.Js - A compiler for a subset of JavaScript expressions
For sample code showing how to use the API, see xref:Lucene.Net.Expressions.Expression.