Add patterns module: pattern matching from JDK 21 to 27

Type, record and primitive patterns, guards, sealed exhaustiveness, MatchException via separate compilation, and eight captured transcripts. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01TF9JWFvJSNm6HVzswzZU5a
2026-09-24 11:50:40 +00:00
parent 96b25c8fc4
commit bc91b9c8d0
36 changed files with 736 additions and 0 deletions
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+public class NotExhaustive {
+    sealed interface Shape permits Circle, Square, Rect {}
+    record Circle(double r) implements Shape {}
+    record Square(double side) implements Shape {}
+    record Rect(double w, double h) implements Shape {}
+
+    static double area(Shape s) {
+        return switch (s) {
+            case Circle(double r) -> Math.PI * r * r;
+            case Square(double side) -> side * side;
+            // Rect is missing
+        };
+    }
+    public static void main(String[] args) { System.out.println(area(new Circle(1))); }
+}