| /* |
| * Copyright 2000-2014 JetBrains s.r.o. |
| * |
| * 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.intellij.util.containers; |
| |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| import java.util.*; |
| |
| /** |
| * A drop-in replacement for {@link java.util.Stack} based on {@link java.util.ArrayList} (instead of {@link java.util.Vector}) |
| * and therefore is (1) not synchronized and (2) faster. |
| * |
| * @author max |
| */ |
| public class Stack<T> extends ArrayList<T> { |
| public Stack() { } |
| |
| public Stack(int initialCapacity) { |
| super(initialCapacity); |
| } |
| |
| public Stack(@NotNull Collection<T> init) { |
| super(init); |
| } |
| |
| public Stack(@NotNull T... items) { |
| for (T item : items) { |
| push(item); |
| } |
| } |
| |
| public void push(T t) { |
| add(t); |
| } |
| |
| public T peek() { |
| final int size = size(); |
| if (size == 0) throw new EmptyStackException(); |
| return get(size - 1); |
| } |
| |
| public T pop() { |
| final int size = size(); |
| if (size == 0) throw new EmptyStackException(); |
| return remove(size - 1); |
| } |
| |
| @Nullable |
| public T tryPop() { |
| return isEmpty() ? null : pop(); |
| } |
| |
| public boolean empty() { |
| return isEmpty(); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (o instanceof RandomAccess && o instanceof List) { |
| List other = (List)o; |
| if (size() != other.size()) { |
| return false; |
| } |
| |
| for (int i = 0; i < other.size(); i++) { |
| Object o1 = other.get(i); |
| Object o2 = get(i); |
| if (!(o1 == null ? o2 == null : o1.equals(o2))) { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| return super.equals(o); |
| } |
| } |