/* * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /** * @test */ import java.util.Objects; public class NestedDeconstructionPattern { public static void main(String... args) throws Throwable { new NestedDeconstructionPattern().doTestR(); new NestedDeconstructionPattern().doTestP(); } void doTestR() { assertEquals("AA", switchR1(new R(new A(), new A()))); assertEquals("AB", switchR1(new R(new A(), new B()))); assertEquals("BA", switchR1(new R(new B(), new A()))); assertEquals("BB", switchR1(new R(new B(), new B()))); try { switchR1(null); throw new AssertionError("Didn't get a NPE."); } catch (NullPointerException ex) { //OK } assertEquals("AA", switchR2(new R(new A(), new A()))); assertEquals("AB", switchR2(new R(new A(), new B()))); assertEquals("BA", switchR2(new R(new B(), new A()))); assertEquals("BB", switchR2(new R(new B(), new B()))); assertEquals("other", switchR2("")); try { switchR2(null); throw new AssertionError("Didn't get a NPE."); } catch (NullPointerException ex) { //OK } } String switchR1(R r) { return switch (r) { case R(A a, A b) -> a.name() + b.name(); case R(A a, B b) -> a.name() + b.name(); case R(B a, A b) -> a.name() + b.name(); case R(B a, B b) -> a.name() + b.name(); }; } String switchR2(Object o) { return switch (o) { case R(A a, A b) -> a.name() + b.name(); case R(A a, B b) -> a.name() + b.name(); case R(B a, A b) -> a.name() + b.name(); case R(B a, B b) -> a.name() + b.name(); default -> "other"; }; } void doTestP() { assertEquals("AAAA", switchP1(new P(new R(new A(), new A()), new R(new A(), new A())))); } String switchP1(P p) { return switch (p) { case P(R(A a1, A b1), R(A a2, A b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(A a1, A b1), R(A a2, B b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(A a1, A b1), R(B a2, A b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(A a1, A b1), R(B a2, B b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(A a1, B b1), R(A a2, A b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(A a1, B b1), R(A a2, B b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(A a1, B b1), R(B a2, A b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(A a1, B b1), R(B a2, B b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(B a1, A b1), R(A a2, A b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(B a1, A b1), R(A a2, B b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(B a1, A b1), R(B a2, A b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(B a1, A b1), R(B a2, B b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(B a1, B b1), R(A a2, A b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(B a1, B b1), R(A a2, B b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(B a1, B b1), R(B a2, A b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(R(B a1, B b1), R(B a2, B b2)) -> a1.name() + b1.name()+a2.name() + b2.name(); case P(N a, N b) -> "other"; }; } public sealed interface I {} public final class A implements I { public String name() { return "A"; } } public final class B implements I { public String name() { return "B"; } } public record R(I a, I b) implements N {} public sealed interface N {} public final class C implements N { public String name() { return "B"; } } public record P(N a, N b) { } private void assertEquals(String expected, String actual) { if (!Objects.equals(expected, actual)) { throw new AssertionError("Expected: " + expected + ", but got: " + actual); } } }