We use the traversable instance on List to reimplement Promise.all() type functionality.

 

For example we want to conver:

[Task] => Task([])

Conver array of Task, into Task of array value.

 

To do that we can use traverse.

const fs = require('fs')const Task = require('data.task')const futurize = require('futurize').futurize(Task)const { List } = require('immutable-ext')const readFile = futurize(fs.readFile)const files = List(['box.js', 'config.json'])files.traverse(Task.of, fn => readFile(fn, 'utf-8')).fork(console.error, console.log)