linked-list

linked-list

Minimalistic linked lists.

Installation

npm:

$ npm install linked-list

Component:

$ component install wooorm/linked-list

Bower:

$ bower install linked-list

Standalone library:

<script src="/your/js/path/linked-list.globals.js"></script>

Download the latest minified standalone release and add it to your project. Include the above snippet in your HTML. This makes the LinkedList module available in the global namespace (window in the browser).

Usage

“Simple”

var LinkedList = require('linked-list'); // or use AMD, or globals.

var item = new LinkedList.Item();
var item_ = new LinkedList.Item();
var item__ = new LinkedList.Item();
var list = new LinkedList(item, item_, item__);

list.head // => item
list.head.next // => item_
list.head.next.next // => item__
list.head.next.prev // => item
list.tail // => item__
list.tail.next // => `null`

Subclassing

var extend = require('some-extending-method...'); // e.g. assimilate.
var List = require('linked-list');
var Item = List.Item;

function Tokens() {
    List.apply(this, arguments);
};

function Token(value) {
    this.value = value;
};

extend(Tokens.prototype, List.prototype, {
    'join' : function(delimeter){
        return this.toArray().join(delimeter);
    }
});

extend(Token.prototype, Item.prototype, {
    'toString' : function(){
        return this.value;
    }
});

var dogs = new Token('dogs');
var and = new Token('&');
var cats = new Token('cats');
var tokens = new Tokens(dogs, and, cats);

tokens.join(' '); // "dogs & cats"

and.prepend(cats);
and.append(dogs);

tokens.join(' ') + '!'; // "cats & dogs!"

API

LinkedList([items…])

var list = new LinkedList();

Creates a new Linked List.

LinkedList.from([items[…]])

var list = LinkedList.from(),
    list_ = LinkedList.from([]),
    list__ = LinkedList.from([new LinkedList.Item()]);

Creates a new Linked List* from the given array of items. Ignores null or undefined values. Throws an error when a given item has no detach, append, or prepend methods.

• Actually, a new instance of this, e.g. when placed on Token (Token.from), it would create a new instance of Token.

LinkedList.of([items…])

var list = LinkedList.of(),
    list_ = LinkedList.of(new LinkedList.Item());

Creates a new Linked List from the given arguments. Defers to LinkedList.from (see above). As in:

List.of = function (/*items...*/) {
    return List.from.call(this, arguments);
};

LinkedList#append(item)

var list = new LinkedList(),
    item = new LinkedList.Item();

list.head === null // true
item.list === null // true

list.append(item);

list.head === item // true
item.list === list // true

Appends an item to a list. Throws an error when the given item has no detach, append, or prepend methods. Returns the given item.

LinkedList#prepend(item)

var list = new LinkedList(),
    item = new LinkedList.Item();

list.prepend(item);

Prepends an item to a list. Throws an error when the given item has no detach, append, or prepend methods. Returns the given item.

LinkedList#toArray()

var item = new LinkedList.Item(),
    item_ = new LinkedList.Item(),
    list = new LinkedList(item, item_),
    array = list.toArray();

array[0] === item // true
array[1] === item_ // true
array[0].next === item_ // true
array[1].prev === item // true

Returns the items in the list in an array.

LinkedList#head

var item = new LinkedList.Item(),
    list = new LinkedList(item);

list.head === item; // true

The first item in a list, and null otherwise.

LinkedList#tail

var list = new LinkedList(),
    item = new LinkedList.Item(),
    item_ = new LinkedList.Item();

list.tail === null; // true

list.append(item);
list.tail === null; // true, see note.

list.append(item_);
list.tail === item_; // true

The last item in a list, and null otherwise. Note that a list with only one item has no tail, only a head.

LinkedList.Item()

var item = new LinkedList.Item();

Creates a new Linked List Item.

LinkedList.Item#append(item)

var item = new LinkedList.Item(),
    item_ = new LinkedList.Item();

(new LinkedList()).append(item);

item.next === null // true

item.append(item_);
item.next === item_ // true

Adds the given item after the operated on item in a list. Throws an error when the given item has no detach, append, or prepend methods. Returns false when the operated on item is not attached to a list, otherwise the given item.

LinkedList.Item#prepend(item)

var item = new LinkedList.Item(),
    item_ = new LinkedList.Item();

(new LinkedList()).append(item);

item.prev === null // true

item.prepend(item_);
item.prev === item_ // true

Adds the given item before the operated on item in a list. Throws an error when the given item has no detach, append, or prepend methods. Returns false when the operated on item is not attached to a list, otherwise the given item.

LinkedList.Item#detach()

var item = new LinkedList.Item(),
    list = new LinkedList(item);

item.list === list // true

item.detach();
item.list === null // true

Removes the operated on item from its parent list. Removes references to it on its parent list, and prev and next items; relinking them when possible. Returns the operated on item. Even when it was already detached.

LinkedList.Item#next

var item = new LinkedList.Item(),
    item_ = new LinkedList.Item();

new LinkedList(item);

item.next === null // true
item_.next === null // true

item.append(item_);

item.next === item_ // true

item.detach();

item.next === null // true

The items succeeding item, and null otherwise.

LinkedList.Item#prev

var item = new LinkedList.Item(),
    item_ = new LinkedList.Item();

new LinkedList(item);

item.prev === null // true
item_.prev === null // true

item.append(item_);

item_.prev === item // true

item_.detach();

item_.prev === null // true

The items preceding item, and null otherwise.

LinkedList.Item#list

var item = new LinkedList.Item(),
    list = new LinkedList();

item.list === null // true

list.append(item);

item.list === list // true

item.detach();

item.list === null // true

The items parent list, and null otherwise.

Licence

MIT © Titus Wormer