| // Copyright 2016 The Bazel Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| package com.google.devtools.build.android.desugar.testdata; |
| |
| import com.google.devtools.build.android.desugar.testdata.separate.SeparateBaseClass; |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.concurrent.Callable; |
| import java.util.function.Function; |
| import java.util.function.Predicate; |
| import java.util.stream.Collectors; |
| |
| public class MethodReference extends SeparateBaseClass<String> { |
| |
| private final List<String> names; |
| |
| public MethodReference(List<String> names) { |
| super(names); |
| this.names = names; |
| } |
| |
| // Class method reference |
| public void appendAll(StringBuilder dest) { |
| names.stream().forEach(dest::append); |
| } |
| |
| // Interface method reference (regression test for b/33304582) |
| public List<String> transform(Transformer<String> transformer) { |
| return names.stream().map(transformer::transform).collect(Collectors.toList()); |
| } |
| |
| // Private method reference (regression test for b/33378312) |
| public List<String> some() { |
| return names.stream().filter(MethodReference::startsWithS).collect(Collectors.toList()); |
| } |
| |
| // Protected method reference in a base class of another package (regression test for b/33378312) |
| public List<String> intersect(List<String> other) { |
| return other.stream().filter(this::contains).collect(Collectors.toList()); |
| } |
| |
| // Contains the same method reference as intersect |
| public List<String> onlyIn(List<String> other) { |
| Predicate<String> p = this::contains; |
| return other.stream().filter(p.negate()).collect(Collectors.toList()); |
| } |
| |
| // Private method reference to an instance method that throws (regression test for b/33378312) |
| public Callable<String> stringer() { |
| return this::throwing; |
| } |
| |
| /** Returns a method reference derived from an expression (object.toString()). */ |
| public static Function<Integer, Character> stringChars(Object object) { |
| return (object == null ? "" : object.toString())::charAt; |
| } |
| |
| /** Returns a method reference derived from a field */ |
| public Predicate<String> toPredicate() { |
| return names::contains; |
| } |
| |
| private static boolean startsWithS(String input) { |
| return input.startsWith("S"); |
| } |
| |
| private String throwing() throws Exception { |
| StringBuilder msg = new StringBuilder(); |
| appendAll(msg); |
| throw new IOException(msg.toString()); |
| } |
| |
| /** Interface to create a method reference for in {@link #transform}. */ |
| public interface Transformer<T> { |
| T transform(T input); |
| } |
| } |