# Package org.apache.lucene.expressions

package org.apache.lucene.expressions
Expressions.

`Expression` - result of compiling an expression, which can evaluate it for a given document. Each expression can have external variables are resolved by `Bindings`.

`Bindings` - abstraction for binding external variables to a way to get a value for those variables for a particular document (DoubleValuesSource).

`SimpleBindings` - default implementation of bindings which provide easy ways to bind sort fields and other expressions to external variables

Related Packages
Package
Description
org.apache.lucene.expressions.js
Javascript expressions.
Classes
Class
Description
Bindings
Binds variable names in expressions to actual data.
Expression
Base class that computes the value of an expression for a document.
SimpleBindings
Simple class that binds expression variable names to `DoubleValuesSource`s or other `Expression`s.