fvi-node-utils/lib/arrays/index.js

Freunde Von Idden - Node Utils Library

'use strict'

const collect = require('collect.js')

const { toJson, toBase64 } = require('../objects')

const flatmap = (f, a) => {
  return a.map(f).reduce((xs, ys) => [...xs, ...ys])
}

/*
 * Para utilizar com arrays e funcoes async,
 * o filter do array nao funciona no
 * contexto async.
 */
const asyncFilter = async (asyncPredicate, xs) => {
  return await xs.reduce(async (acc, x) => {
    const result = await asyncPredicate(x)
    if (result) {
      ;(await acc).push(x)
    }
    return acc
  }, Promise.resolve([]))
}

const arrayToJson = array => {
  return array == null ? [] : array.map(toJson)
}

const arrayToBase64 = array => {
  return array == null ? [] : array.map(toBase64)
}

const chunk = (array, n) =>
  array.slice(0, ((array.length + n - 1) / n) | 0).map((c, i) => array.slice(n * i, n * i + n))

module.exports = {
  chunk,
  flatmap,
  asyncFilter,
  arrayToBase64,
  arrayToJson,
  collect,
}