circularr

Circularr

Circular fixed size array

Install

npm i circularr

Usage

import Circularr from 'circularr'

// Create from
const arrFrom = Circularr.from([1, 2, 3, 4, 5])

// Create new with fixed size
const arr = new Circular(3) // [undefined, undefined, undefined]

// fill using value
arr.fill(0)   // [0, 0, 0]

// shift in some values
arr.shift(16) // [0, 0, 16]
arr.shift(32) // [0, 16, 32]

// check contents
console.log(...arr) // undefined, 16, 32 

Api

class Circularr<T> {

  // create Circularr
  constructor(length: number)
  static from<T>(source: T[]): Circularr<T>
  
  // property
  readonly length: number
  
  // iterable
  [Symbol.iterator](): IterableIterator<T>
  
  // methods
  fill(value: T): this
  shift(value: T): T
  unshift(value: T): T
}

Fill

fill(value: T): this

Fills the array using value, effectively resetting it. Returns this.

const circularr = new Circularr(3) // [undefined, undefined, undefined]

circularr.fill(0) // [0, 0, 0]

Shift

shift(value: T): T

shift method pushes the value to the end of the array, wherein the first value gets popped out and returned.

const circularr = new Circularr(3).fill(0)

circularr.shift(8)   // [0, 0, 8] => 0
circularr.shift(16)  // [0, 8, 16] => 0
circularr.shift(32)  // [8, 16, 32] => 0
circularr.shift(64)  // [16, 32, 64] => 8
circularr.length     // 3

Unshift

unshift(value: T): T

unshift does the opposite. It pushes the value to the front, popping the last value out.

const circularr = new Circularr(3).fill(0)

circularr.unshift(8)   // [8, 0, 0] => 0
circularr.unshift(16)  // [16, 8, 0] => 0
circularr.unshift(32)  // [32, 16, 8] => 0
circularr.unshift(64)  // [64, 32, 16] => 8
circularr.length       // 3

Iterable

Circular implements iterable protocol, so it can be used with any standard iterable syntax

const circularr = Circularr.from([1, 2, 3])

// array destructuring
const [firstValue] = circularr

// destructuring copy
const copyToArray = [...circularr]

// for..of syntax
for (let value of circularr) {
  console.log(value)
}