tweinfeld

let allConcurrent = function(limit, generators){
  return new Promise(function(resolveAll){
    let plan = generators.map((generator)=>({ value: undefined, executed: false, settled: false, generator: generator }));
    let executeBatch = () => {
      plan
        .filter(({ settled, executed })=> !executed || (executed && !settled))
        .slice(0, limit)
        .filter(({ executed }) => !executed)
        .map(planItem => {
          planItem.executed = true;

cem2ran

const combine = (...arrays)
  => [].concat(...arrays);

const compact = arr
  => arr.filter(el => el);

const contains = (() => Array.prototype.includes
  ? (arr, value) => arr.includes(value)
  : (arr, value) => arr.some(el => el === value)
)();