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; | |
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"]; |