iter-tools-es/impls/$zip-all/async-zip-all.js

The iterable toolbox

const {
  asyncIterableCurry
} = require('../../internal/async-iterable.js');

const {
  asyncParallelEach
} = require('../../internal/async-parallel-each.js');

const {
  __asyncPeekerate
} = require('../$peekerate/async-peekerate.js');

const {
  __asyncMap
} = require('../$map/async-map.js');

const {
  __every
} = require('../$every/every.js');

const {
  __asyncToArray
} = require('../$to-array/async-to-array.js');

const isDone = peekr => peekr.done;

async function* __asyncZipAll(sources, {
  filler
} = {}) {
  const peekrs = await __asyncToArray(__asyncMap(sources, __asyncPeekerate));

  let done = __every(peekrs, isDone);

  try {
    while (!done) {
      yield peekrs.map(({
        value,
        done
      }) => done ? filler : value);
      await asyncParallelEach(peekrs, peekr => peekr.advance());
      done = __every(peekrs, isDone);
    }
  } finally {
    await asyncParallelEach(peekrs, peekr => peekr.return());
  }
}

exports.__asyncZipAll = __asyncZipAll;
const asyncZipAll = /*#__PURE__*/asyncIterableCurry(__asyncZipAll, {
  variadic: true,
  minArgs: 0,
  maxArgs: 1
});
exports.asyncZipAll = asyncZipAll;