| /* |
| * 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.idea.blaze.cpp; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.Sets; |
| |
| import java.util.Set; |
| |
| /** |
| * A list where an item is only added if it is not already in the list. |
| */ |
| final class UniqueListBuilder<T> { |
| private final Set<T> set = Sets.newLinkedHashSet(); |
| |
| /** |
| * Add {@param element} if it is not already in the list. |
| * @return true if the element has been added, false otherwise. |
| */ |
| public boolean add(T element) { |
| return set.add(element); |
| } |
| |
| /** |
| * For each element in {@param elements} add the element to the list if it is not already in the list. |
| */ |
| public void addAll(Iterable<T> elements) { |
| for (T element : elements) { |
| add(element); |
| } |
| } |
| |
| public ImmutableList<T> build() { |
| return ImmutableList.copyOf(set); |
| } |
| } |