| // Copyright (c) 2020, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| package com.android.tools.r8.utils; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.function.Predicate; |
| |
| public class IterableUtils { |
| |
| public static <T> List<T> ensureUnmodifiableList(Iterable<T> iterable) { |
| List<T> list; |
| if (iterable instanceof List<?>) { |
| list = (List<T>) iterable; |
| } else { |
| list = toNewArrayList(iterable); |
| } |
| return Collections.unmodifiableList(list); |
| } |
| |
| public static <T> int firstIndexMatching(Iterable<T> iterable, Predicate<T> tester) { |
| int i = 0; |
| for (T element : iterable) { |
| if (tester.test(element)) { |
| return i; |
| } |
| i++; |
| } |
| return -1; |
| } |
| |
| public static <T> Iterable<T> filter(Iterable<T> iterable, Predicate<T> predicate) { |
| return () -> IteratorUtils.filter(iterable.iterator(), predicate); |
| } |
| |
| public static <T> int size(Iterable<T> iterable) { |
| int result = 0; |
| for (T element : iterable) { |
| result++; |
| } |
| return result; |
| } |
| |
| public static <T> List<T> toNewArrayList(Iterable<T> iterable) { |
| List<T> result = new ArrayList<>(); |
| iterable.forEach(result::add); |
| return result; |
| } |
| } |