Class PatternMatchingSwitchPreviewExamples

java.lang.Object

net.jrodolfo.java_evolution.java19.PatternMatchingSwitchPreviewExamples

public class PatternMatchingSwitchPreviewExamples
extends Object

Demonstrates the continued preview of pattern matching for switch in Java 19.

Type-based dispatch used to be written with chains of instanceof checks and casts. Pattern matching for switch lets the switch itself express the type patterns, making this style of branching more compact and easier to audit.

Pattern matching for switch became final later, in Java 21. The type-pattern form shown here was part of the Java 19 preview and remains faithful to it.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	PatternMatchingSwitchPreviewExamples.Event	Closed event hierarchy used to demonstrate exhaustive switch handling.
static final record	PatternMatchingSwitchPreviewExamples.Login	Event representing a user login.
static final record	PatternMatchingSwitchPreviewExamples.Logout	Event representing a user logout.

Constructor Summary

Constructors

Constructor	Description
PatternMatchingSwitchPreviewExamples()

Method Summary

Modifier and Type	Method	Description
String	describe(PatternMatchingSwitchPreviewExamples.Event event)	Switches over a sealed hierarchy with type patterns.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PatternMatchingSwitchPreviewExamples

public PatternMatchingSwitchPreviewExamples()

Method Details

describe

public String describe(PatternMatchingSwitchPreviewExamples.Event event)

Switches over a sealed hierarchy with type patterns.

Parameters:

event - the event to describe

Returns:

a type-specific event description