Maybe

Yet another Maybe type written by vanilla.js

Inspired by Haskell's Maybe type

Can be used in browser,node and requireJs

Installation

On browser or requireJs, just copy the src/maybe.js to desired path then use like this

<script src="/yourpath/maybe.js"></script>
<script>
  // Lib export 'M' to global
  console.log(M.or(M.just('Hello kobako-maybe'),'Oh no'))
</script>

By npm

$ npm install kobako-maybe

Usage

Import the lib:

const M = require('kobako-maybe')

Use the just of nothing function to create a Maybe type from a value

const value = M.just(1)

M.isJust(value) //true
M.isNothing(value) //false

const val2 = M.nothing()

M.isJust(val2) //false
M.isNothing(val2) //true

Use map to lift a function: you can use a traditional function on a Maybe value

const value = M.just(1)
const nothing = M.nothing()

M.map(x => x+1, value) //Just 2
M.map(x => x+1, nothing) //Nothing

Use or to unwrap value from Maybe

M.or(M.just(1),-1) //1
M.or(M.nothing(),-1) //-1