> ## Documentation Index
> Fetch the complete documentation index at: https://aletyx.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# DRL

> An introduction to the Drools Rule Language (DRL): what it is, why to use it, how it compares to alternatives, and where it fits in your architecture.

## Introduction to Drools Rule Language

* **What is DRL?** - A clear, approachable definition for newcomers
* **Why Use DRL?** - Business benefits and technical advantages
* **DRL vs Other Rules Approaches** - Quick comparison with alternatives (SQL, decision tables, etc.)
* **Where DRL Fits in Your Architecture** - How it integrates with Java applications

## Getting Started with DRL

* **Your First DRL Rule** - Simple hands-on example with explanation
* **Basic Rule Structure** - The fundamental components of a rule
* **Syntax Overview** - Basic patterns and conventions
* **Common Use Cases** - Everyday scenarios where DRL shines

## DRL Building Blocks

* **Packages** - Organization and namespaces
* **Imports** - Working with Java classes
* **Rule Units** - Modern rule organization approach
* **Rule Structure** - Detailed breakdown of rule components
* Rule name
* Attributes
* Conditions (when)
* Actions (then)

## Working with Data in DRL

* **Facts and Data Sources** - Understanding the data that rules operate on
* **Type Declarations** - Creating and using fact types
* **Data Binding** - How to reference fact properties
* **Accessing Properties** - Different ways to extract and use data

## Rule Conditions

* **Pattern Matching** - The foundation of rule conditions
* **OOPath Expressions** - Modern object traversal approach
* **Constraint Operators** - Comparing and evaluating data
* **Complex Condition Elements** - Combining conditions with and, or, exists, not, etc.
* **Collections and Accumulations** - Working with groups of facts

## Rule Actions

* **Modifying Working Memory** - insert, update, delete operations
* **Modifying Facts** - Changing properties safely
* **Executing Functions** - Calling methods from rules
* **Best Practices for Actions** - Keeping actions clean and maintainable

## Advanced DRL Features

* **Rule Attributes** - Controlling rule behavior
* **Timers and Calendars** - Time-based rule execution
* **Queries** - Retrieving data from working memory
* **Metadata** - Adding annotations to rules and facts
* **Rule Inheritance** - Building rule hierarchies

## DRL in Practice

* **Testing Rules** - Strategies for verification
* **Debugging Tips** - Common issues and solutions
* **Performance Optimization** - Making rules efficient
* **Integration Patterns** - Connecting rules with applications

## Reference

* **Complete Syntax Reference** - Comprehensive syntax guide
* **Operator Precedence** - How operators are evaluated
* **Supported Functions** - Built-in capabilities
* **Railroad Diagrams** - Visual syntax representation

## Appendix

* **Transitioning from Traditional to Modern Syntax**
* **Migrating from Other Rule Systems**
* **Glossary of Terms**