# Lucene 8.6.3 expressions API

The Expressions Module for Apache Lucene

See: Description

Packages
org.apache.lucene.expressions: Expressions.
org.apache.lucene.expressions.js: Javascript expressions.

# The Expressions Module for Apache Lucene

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. `org.apache.lucene.expressions` - The abstractions and simple utilities for common operations like sorting on an expression
2. `org.apache.lucene.expressions.js` - A compiler for a subset of JavaScript expressions

For sample code showing how to use the API, see `Expression`.