| /* |
| * Copyright (c) 2015, 2016, 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * 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 |
| * @bug 8139885 |
| * @run testng/othervm -ea -esa test.java.lang.invoke.FoldTest |
| */ |
| |
| package test.java.lang.invoke; |
| |
| import java.io.StringWriter; |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodHandles; |
| import java.lang.invoke.MethodHandles.Lookup; |
| import java.lang.invoke.MethodType; |
| |
| import static java.lang.invoke.MethodType.methodType; |
| |
| import static org.testng.AssertJUnit.*; |
| |
| import org.testng.annotations.*; |
| |
| /** |
| * Tests for the new fold method handle combinator added in JEP 274. |
| */ |
| public class FoldTest { |
| |
| static final Lookup LOOKUP = MethodHandles.lookup(); |
| |
| @Test |
| public static void testFold0a() throws Throwable { |
| // equivalence to foldArguments(MethodHandle,MethodHandle) |
| MethodHandle fold = MethodHandles.foldArguments(Fold.MH_multer, 0, Fold.MH_adder); |
| assertEquals(Fold.MT_folded1, fold.type()); |
| assertEquals(720, (int) fold.invoke(3, 4, 5)); |
| } |
| |
| @Test |
| public static void testFold1a() throws Throwable { |
| // test foldArguments for folding position 1 |
| MethodHandle fold = MethodHandles.foldArguments(Fold.MH_multer, 1, Fold.MH_adder1); |
| assertEquals(Fold.MT_folded1, fold.type()); |
| assertEquals(540, (int) fold.invoke(3, 4, 5)); |
| } |
| |
| @Test |
| public static void testFold0b() throws Throwable { |
| // test foldArguments equivalence with multiple types |
| MethodHandle fold = MethodHandles.foldArguments(Fold.MH_str, 0, Fold.MH_comb); |
| assertEquals(Fold.MT_folded2, fold.type()); |
| assertEquals(23, (int) fold.invoke("true", true, 23)); |
| } |
| |
| @Test |
| public static void testFold1b() throws Throwable { |
| // test folgArguments for folding position 1, with multiple types |
| MethodHandle fold = MethodHandles.foldArguments(Fold.MH_str, 1, Fold.MH_comb2); |
| assertEquals(Fold.MT_folded3, fold.type()); |
| assertEquals(1, (int) fold.invoke(true, true, 1)); |
| assertEquals(-1, (int) fold.invoke(true, false, -1)); |
| } |
| |
| @Test |
| public static void testFoldArgumentsExample() throws Throwable { |
| // test the JavaDoc foldArguments-with-pos example |
| StringWriter swr = new StringWriter(); |
| MethodHandle trace = LOOKUP.findVirtual(StringWriter.class, "write", methodType(void.class, String.class)).bindTo(swr); |
| MethodHandle cat = LOOKUP.findVirtual(String.class, "concat", methodType(String.class, String.class)); |
| assertEquals("boojum", (String) cat.invokeExact("boo", "jum")); |
| MethodHandle catTrace = MethodHandles.foldArguments(cat, 1, trace); |
| assertEquals("boojum", (String) catTrace.invokeExact("boo", "jum")); |
| assertEquals("jum", swr.toString()); |
| } |
| |
| static class Fold { |
| |
| static int adder(int a, int b, int c) { |
| return a + b + c; |
| } |
| |
| static int adder1(int a, int b) { |
| return a + b; |
| } |
| |
| static int multer(int x, int q, int r, int s) { |
| return x * q * r * s; |
| } |
| |
| static int str(boolean b1, String s, boolean b2, int x) { |
| return b1 && s.equals(String.valueOf(b2)) ? x : -x; |
| } |
| |
| static boolean comb(String s, boolean b2) { |
| return !s.equals(b2); |
| } |
| |
| static String comb2(boolean b2, int x) { |
| int ib = b2 ? 1 : 0; |
| return ib == x ? "true" : "false"; |
| } |
| |
| static final Class<Fold> FOLD = Fold.class; |
| |
| static final MethodType MT_adder = methodType(int.class, int.class, int.class, int.class); |
| static final MethodType MT_adder1 = methodType(int.class, int.class, int.class); |
| static final MethodType MT_multer = methodType(int.class, int.class, int.class, int.class, int.class); |
| static final MethodType MT_str = methodType(int.class, boolean.class, String.class, boolean.class, int.class); |
| static final MethodType MT_comb = methodType(boolean.class, String.class, boolean.class); |
| static final MethodType MT_comb2 = methodType(String.class, boolean.class, int.class); |
| |
| static final MethodHandle MH_adder; |
| static final MethodHandle MH_adder1; |
| static final MethodHandle MH_multer; |
| static final MethodHandle MH_str; |
| static final MethodHandle MH_comb; |
| static final MethodHandle MH_comb2; |
| |
| static final MethodType MT_folded1 = methodType(int.class, int.class, int.class, int.class); |
| static final MethodType MT_folded2 = methodType(int.class, String.class, boolean.class, int.class); |
| static final MethodType MT_folded3 = methodType(int.class, boolean.class, boolean.class, int.class); |
| |
| static { |
| try { |
| MH_adder = LOOKUP.findStatic(FOLD, "adder", MT_adder); |
| MH_adder1 = LOOKUP.findStatic(FOLD, "adder1", MT_adder1); |
| MH_multer = LOOKUP.findStatic(FOLD, "multer", MT_multer); |
| MH_str = LOOKUP.findStatic(FOLD, "str", MT_str); |
| MH_comb = LOOKUP.findStatic(FOLD, "comb", MT_comb); |
| MH_comb2 = LOOKUP.findStatic(FOLD, "comb2", MT_comb2); |
| } catch (Exception e) { |
| throw new ExceptionInInitializerError(e); |
| } |
| } |
| } |
| |
| } |