| /* |
| * Copyright 2016-2017 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 kotlinx.coroutines.experimental.internal |
| |
| private typealias Node = LinkedListNode |
| |
| /** |
| * @suppress **This is unstable API and it is subject to change.** |
| */ |
| public open class LinkedListNode { |
| public var next = this |
| private set |
| public var prev = this |
| private set |
| public var isRemoved: Boolean = false |
| private set |
| public val isFresh: Boolean = next === this |
| |
| public fun addLast(node: Node) { |
| val prev = this.prev |
| node.next = this |
| node.prev = prev |
| prev.next = node |
| this.prev = node |
| } |
| |
| public open fun remove(): Boolean { |
| if (isRemoved) return false |
| val prev = this.prev |
| val next = this.next |
| prev.next = next |
| next.prev = prev |
| isRemoved = true |
| return true |
| } |
| } |
| |
| /** |
| * @suppress **This is unstable API and it is subject to change.** |
| */ |
| public open class LinkedListHead : LinkedListNode() { |
| public val isEmpty get() = next === this |
| |
| /** |
| * Iterates over all elements in this list of a specified type. |
| */ |
| public inline fun <reified T : Node> forEach(block: (T) -> Unit) { |
| var cur: Node = next |
| while (cur != this) { |
| if (cur is T) block(cur) |
| cur = cur.next |
| } |
| } |
| |
| // just a defensive programming -- makes sure that list head sentinel is never removed |
| public final override fun remove() = throw UnsupportedOperationException() |
| |
| fun removeFirstOrNull(): Node? { |
| val node = next |
| if (node === this) return null |
| node.remove() |
| return node |
| } |
| } |
| |