@akashbabu/node-dll

node-dll

DLL(Doubly linked list) implementation for javascript projects

Introduction

Doubly linked list(DLL) is inevitable in certain situation where performance is preferred while slicing an array (maybe there are more to it, but this is mostly my PoV). So this library was created with a simple, yet powerful interface for interacting with the underlying DLL schema.

This library is written in typescript for robust APIs and type support.

Documentation

API method name has been carefully chosen to nearly match Array methods, such that learning curve is least and adaptability is higher. But a few methods could not have had a different name and we'd to convince ourselves with those method name.

API - DLL

import {DLL} from 'node-dll';

constructor():

This creates a new instance of DLL

Example:

const dll = new DLL();

.getHead()

Returns the first item in the list

Example:

const dll = new DLL()
dll.push('test')

dll.getHead() // => DLLItem<'test'>

.getTail()

Returns the last item in the list

Example:

const dll = new DLL()
dll.push('test1')
dll.push('test2')

dll.getTail() // => DLLItem<'test2'>

.shift()

Removes and returns the first item in the list

Example:

const dll = new DLL()
dll.push('test1')
dll.push('test2')

dll.shift() // => 'test1'

dll.length // => 1

.unshift()

Add the given item to the head of DLL chain

Example:

const dll = new DLL()
dll.push('test1')
dll.unshift('test0')

dll.getHead() // => DLLItem<'test1'>

dll.length // => 2

.forEach(cb)

Iterates through the entire DLL chain

Example:

const dll = new DLL()
dll.push('test1')
dll.push('test2')

dll.forEach((data, i) => {
  console.log(data, i)
})

// => test1 0
// => test2 1

.map(cb)

Iterates through the entire DLL chain and returns a resultant array

Example:

const dll = new DLL()
dll.push('test1')
dll.push('test2')

const results = dll.map((data, i) => {
  return `${i + 1}) ${data}`;
})

console.log(results) // => ['1) test1', '2) test2']

.push(data)

Adds the given items to the tail of DLL chain and returns the added item, such that the same can be used to remove the item from the list

Example:

const dll = new DLL()

const item = dll.push('test1')

dll.length // => 1
dll.getHead() // => DLLItem<'test1'>

dll.remove(item)

dll.length // => 0

.remove(dllItem)

Removes the given item from DLL chain and returns true if the removal was successful

Example:

const dll = new DLL()

const item = dll.push('test1')

dll.length // => 1
dll.getHead() // => DLLItem<'test1'>

dll.remove(item) // => true

dll.length // => 0

Contribution

All contributions are welcome!!!

But before raising any issue, please check the issue-tracker in github if there is any matching issues already in the pipeline, if not then please go ahead and raise your own.

PR Guidelines:

• Make sure to include corresponding test cases
• Be generous on code comments
• Write documentation if necessary
• Wait for your approval 😜

Licence

MIT