| // Copyright (c) 2019, 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.Iterator; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| |
| public abstract class ThrowingIterator<T, E extends Exception> { |
| |
| public abstract boolean hasNext(); |
| |
| public abstract T next() throws E; |
| |
| public T computeNextIfAbsent(ThrowingSupplier<T, E> supplier) throws E { |
| if (hasNext()) { |
| return next(); |
| } |
| return supplier.get(); |
| } |
| |
| public List<T> take(int number) throws E { |
| List<T> result = new ArrayList<>(number); |
| while (number > 0) { |
| if (!hasNext()) { |
| throw new NoSuchElementException(); |
| } |
| result.add(next()); |
| number--; |
| } |
| return result; |
| } |
| |
| public static <T, E extends Exception> ThrowingIterator<T, E> fromIterator(Iterator<T> it) { |
| return new ThrowingIterator<>() { |
| @Override |
| public boolean hasNext() { |
| return it.hasNext(); |
| } |
| |
| @Override |
| public T next() throws E { |
| return it.next(); |
| } |
| }; |
| } |
| } |