https://github.com/gpmcadam/swapsy

A simple, tiny, pure ES6 implementation of an array swap method
https://github.com/gpmcadam/swapsy

array es6 functional javascript pure swap swapsy tiny

Last synced: 5 months ago
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A simple, tiny, pure ES6 implementation of an array swap method

• Host: GitHub
• URL: https://github.com/gpmcadam/swapsy
• Owner: gpmcadam
• License: mit
• Created: 2018-03-04T01:45:17.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2018-03-04T02:22:08.000Z (over 7 years ago)
• Last Synced: 2025-02-16T18:46:52.273Z (8 months ago)
• Topics: array, es6, functional, javascript, pure, swap, swapsy, tiny
• Language: JavaScript
• Size: 19.5 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
![swapsy.js](./logo.png?raw=true "Swapsy")

![](https://travis-ci.org/gpmcadam/swapsy.svg?branch=master)

Swap two elements in an array. Easy, peasy.

## Install

    $ npm install swapsy

## Example

    const swapsy = require('swapsy');

    const arr = [ 'hello', 'world' ]

    const fromIndex = 0

    const toIndex = 1

    swapsy(arr, fromIndex, toIndex)

    // Returns [ 'world', 'hello' ]

## Why?

 - ✅ Tiny (~400 bytes)

 - ✅ Zero-Dependencies

 - ✅ Immutable/Pure

 - ✅ ES6

 - ✅ Tested

## Better Example

Suppose you use React and Redux, and you have

some kind of action and a reducer that reorders

some components for the user.

Your action might look like this:

    const swapItems = (from, to) => {

      return {

        type: 'SWAP_ITEMS',

        from,

        to

      }

    }

And your reducer might have looked like this:

    const items = (state = [], ({ from, to })) => {

      switch (action.type) {

        case 'SWAP_ITEMS':

          const x = state[from];

          const y = state[to];

          state[to] = x;

          state[from] = y;

          return state;

      }

    }

Which is bad because it's long, ungainly, wasteful

and mutates the state directly. Also note, there are worse implementations than the one above.

But with swapsy, keep your reducers pure and

readable:

    const swap = require('swapsy');

    const items = (state = [], ({ from, to })) => {

      switch (action.type) {

        case 'SWAP_ITEMS':

          return swap(state, from, to);

      }

    }