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

The iterable toolbox

const {
  iterableCurry
} = require('../../internal/iterable.js');

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

const {
  __peekerate
} = require('../$peekerate/peekerate.js');

const {
  __map
} = require('../$map/map.js');

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

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

const isDone = peekr => peekr.done;

function* __zipAll(sources, {
  filler
} = {}) {
  const peekrs = __toArray(__map(sources, __peekerate));

  let done = __every(peekrs, isDone);

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

exports.__zipAll = __zipAll;
const zipAll = /*#__PURE__*/iterableCurry(__zipAll, {
  variadic: true,
  minArgs: 0,
  maxArgs: 1
});
exports.zipAll = zipAll;