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
@@ -0,0 +1,17 @@
+public class PrimitiveInRecord {
+    record Reading(double celsius) {}
+
+    static String classify(Object o) {
+        return switch (o) {
+            case Reading(int whole) -> "whole degrees: " + whole;     // double component matched against an int pattern
+            case Reading(double d) -> "fractional: " + d;
+            default -> "not a reading";
+        };
+    }
+
+    public static void main(String[] args) {
+        System.out.println(classify(new Reading(21.0)));
+        System.out.println(classify(new Reading(21.5)));
+        System.out.println(classify("x"));
+    }
+}