Add sealed module: modelling domains with sealed types and exhaustive switch

Payment model, permits and the three modifiers, default-branch trap, generic and recursive hierarchies, visitor comparison, run-time enforcement, modules. Transcripts from JDK 21, 25 and 27. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01TF9JWFvJSNm6HVzswzZU5a
2026-09-24 12:03:59 +00:00
parent 65a4bbbbe3
commit ff6130bede
38 changed files with 638 additions and 0 deletions
@@ -0,0 +1,7 @@
+public class AnonymousSealed {
+    sealed interface Payment permits Card {}
+    record Card(long amount) implements Payment {}
+    static Payment sneaky() {
+        return new Payment() {};                          // an anonymous class is a subtype nobody listed
+    }
+}