SideEffector

An Effect monad library. Allows you to defer dealing with impurities until you actually run them.

Quickstart

Importing the library

Import via require

const SideEffector = require('side-effector')

Import as ES module

import SideEffector from 'side-effector'

Import in the browser

<script src="https://cdn.jsdelivr.net/npm/[email protected]/side-effector.min.js"></script>

Using the library

To create a SideEffector, give it a function.

Example:

const lazyZero = SideEffector(() => 0)

Apply a function using map()

To apply a function to this object, we use the map() method. It's important to remember that the function will not be immediately applied.

Example:

const toAddOne = lazyZero.map(x => x + 1)
const toDisplayPlusOne = toAddOne.map(x => console.log(x + 1))

Run the side effects using run()

To actually run the side effects, we use the run() method like this:

Example:

toDisplayPlusOne.run() // 2

Notes

Derived from James Sinclair's post, How to Deal with Dirty Side-Effects in Your Pure Functional JavaScript.

License

MIT