JS CDLL

A JavaScript implementation of the Circular Doubly-Linked List data structure

influenced by:

• http://blog.jcoglan.com/2007/07/23/writing-a-linked-list-in-javascript/ and
• http://www.nczonline.net/blog/2009/04/21/computer-science-in-javascript-doubly-linked-lists/
• and Brophdawg for the object structuring pattern

license: The MIT License (MIT)

author: Chris Braddock ([email protected])

JS CDLL provides the following methods:

• seed(Array) - populate the CDLL
• add(item) - add an item to the CDLL
• addArray(Array) - add an array of items to the CDLL
• insertAfter(node, item) - insert an item after another item in the CDLL
• remove(node) - remove an item from the CDLL
• rotate(+/-Integer) - rotate the CDLL (like a carousel)
• setCurrent(node) - set the current item in the CDLL
• toArray() - return the items of the CDLL in an array
• first() - get the first item in the CDLL
• first().next() [.next()|.prev()] [.next()|.prev()] [...] - get subsequent items in the CDLL
• first().prev() [.next()|.prev()] [.next()|.prev()] [...] - get previous items in the CDLL

Example Usage:

// Instantiate a CDLL (separate seeding step)
var cdll = new CDLL();
cdll.seed(['a', 'b', 'c']);             // ['a', 'b', 'c']

// Instantiate and seed a CDLL
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']

// Add an item to the CDLL
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.add('d');                          // ['a', 'b', 'c', 'd']

// Add an array of items to the CDLL
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.add(['x', 'y', 'z']);              // ['a', 'b', 'c', 'x', 'y', 'z']

// Insert an item in to the CDLL
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.insertAfter(cdll.first(), '1');    // ['a', '1', 'b', 'c']

// Remove an item from the CDLL
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.remove(cdll.first());              // ['b', 'c']

// Rotate the CDLL (forward)
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.rotate(1);
cdll.first();                           // 'b'
cdll.last();                            // 'a'

// Rotate the CDLL (backward)
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.rotate(-1);
cdll.first();                           // 'c'
cdll.last();                            // 'a'

// Set the current CDLL item
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.first();                           // 'a'
cdll.setCurrent(cdll.first().next());
cdll.first();                           // 'b'

// Get the CDLL as an array
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.toArray();                         // ['a', 'b', 'c'] (as the return value of the fn)

// Get items of the CDLL
var cdll = new CDLL(['a', 'b', 'c']]);  // ['a', 'b', 'c']
cdll.first();                           // 'a'
cdll.first().next();                    // 'b'
cdll.last();                            // 'c'
cdll.first().next().next();             // 'c'
cdll.first().prev();                    // 'b'

Contributing:

Fork. Write one or more tests and maybe some code. Submit a pull request.

TODO:

• checkout https://github.com/chenglou/data-structures/wiki/LinkedList for comparison
• html demo page
• more tests
• jsperf tests
• example on jsbin
• make work as a node module
• destroy() method
• bower.js registration