[Javascript Crocks] Make your own functions safer by lifting them into a Maybe context

You probably have functions that aren’t equipped to accept a Maybe as an argument. And in most cases, altering functions to accept a specific container type isn’t desirable. You could use map, passing in your function, or you could “lift” your function into a Maybe context. In this lesson, we’ll look at how we can get a function that accepts raw values to work with our Maybe container without the need to modify the original function or the input values.

 

Imaging you want to double a number:

const crocks = require('crocks');
const { safeLift, safe, isNumber } = crocks;

const dbl = n => n * 2;

const safeDbl = n => safe(isNumber, n).map(dbl);

const res = safeDbl(2).option(0);

console.log(res)

Calling 'safe(pred, n).map(fn)' is also a common partten.

 

We can use 'safeLift' to simplfiy the code:

const crocks = require('crocks');
const { safeLift, safe, isNumber } = crocks;

const dbl = n => n * 2;
/*
const safeDbl = n => safe(isNumber, n).map(dbl);
*/

const safeDbl = safeLift(isNumber, dbl);
const res = safeDbl(2).option(0);

console.log(res)