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- "use strict";
- Object.defineProperty(exports, "__esModule", {
- value: true
- });
- exports.default = DLL;
- // Simple doubly linked list (https://en.wikipedia.org/wiki/Doubly_linked_list) implementation
- // used for queues. This implementation assumes that the node provided by the user can be modified
- // to adjust the next and last properties. We implement only the minimal functionality
- // for queue support.
- function DLL() {
- this.head = this.tail = null;
- this.length = 0;
- }
- function setInitial(dll, node) {
- dll.length = 1;
- dll.head = dll.tail = node;
- }
- DLL.prototype.removeLink = function (node) {
- if (node.prev) node.prev.next = node.next;else this.head = node.next;
- if (node.next) node.next.prev = node.prev;else this.tail = node.prev;
- node.prev = node.next = null;
- this.length -= 1;
- return node;
- };
- DLL.prototype.empty = function () {
- while (this.head) this.shift();
- return this;
- };
- DLL.prototype.insertAfter = function (node, newNode) {
- newNode.prev = node;
- newNode.next = node.next;
- if (node.next) node.next.prev = newNode;else this.tail = newNode;
- node.next = newNode;
- this.length += 1;
- };
- DLL.prototype.insertBefore = function (node, newNode) {
- newNode.prev = node.prev;
- newNode.next = node;
- if (node.prev) node.prev.next = newNode;else this.head = newNode;
- node.prev = newNode;
- this.length += 1;
- };
- DLL.prototype.unshift = function (node) {
- if (this.head) this.insertBefore(this.head, node);else setInitial(this, node);
- };
- DLL.prototype.push = function (node) {
- if (this.tail) this.insertAfter(this.tail, node);else setInitial(this, node);
- };
- DLL.prototype.shift = function () {
- return this.head && this.removeLink(this.head);
- };
- DLL.prototype.pop = function () {
- return this.tail && this.removeLink(this.tail);
- };
- DLL.prototype.toArray = function () {
- var arr = Array(this.length);
- var curr = this.head;
- for (var idx = 0; idx < this.length; idx++) {
- arr[idx] = curr.data;
- curr = curr.next;
- }
- return arr;
- };
- DLL.prototype.remove = function (testFn) {
- var curr = this.head;
- while (!!curr) {
- var next = curr.next;
- if (testFn(curr)) {
- this.removeLink(curr);
- }
- curr = next;
- }
- return this;
- };
- module.exports = exports["default"];
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