| /* |
| * Copyright (c) 2008, 2009, 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. |
| */ |
| |
| package sun.dyn; |
| |
| import java.dyn.JavaMethodHandle; |
| import java.dyn.MethodHandle; |
| import java.dyn.MethodType; |
| |
| /** |
| * Unary function composition, useful for many small plumbing jobs. |
| * The invoke method takes a single reference argument, and returns a reference |
| * Internally, it first calls the {@code filter} method on the argument, |
| * Making up the difference between the raw method type and the |
| * final method type is the responsibility of a JVM-level adapter. |
| * @author jrose |
| */ |
| public class FilterOneArgument extends JavaMethodHandle { |
| protected final MethodHandle filter; // Object -> Object |
| protected final MethodHandle target; // Object -> Object |
| |
| @Override |
| public String toString() { |
| return target.toString(); |
| } |
| |
| protected Object invoke(Object argument) throws Throwable { |
| Object filteredArgument = filter.invoke(argument); |
| return target.invoke(filteredArgument); |
| } |
| |
| private static final MethodHandle INVOKE = |
| MethodHandleImpl.IMPL_LOOKUP.findVirtual(FilterOneArgument.class, "invoke", MethodType.genericMethodType(1)); |
| |
| protected FilterOneArgument(MethodHandle filter, MethodHandle target) { |
| super(INVOKE); |
| this.filter = filter; |
| this.target = target; |
| } |
| |
| public static MethodHandle make(MethodHandle filter, MethodHandle target) { |
| if (filter == null) return target; |
| if (target == null) return filter; |
| return new FilterOneArgument(filter, target); |
| } |
| |
| // MethodHandle make(MethodHandle filter1, MethodHandle filter2, MethodHandle target) { |
| // MethodHandle filter = make(filter1, filter2); |
| // return make(filter, target); |
| // } |
| } |