iter-tools-es/impls/$round-robin/round-robin.js

The iterable toolbox

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

const {
  __interleave
} = require('../$interleave/interleave.js');

const {
  makeValidateArgs
} = require('./internal/validate-args.js');

function* byPosition({
  start,
  step
}, all, ...peekrs) {
  start = start % peekrs.length;

  for (let i = start; !all.done; i = (i + step) % peekrs.length) {
    const peekr = peekrs[i];

    if (!peekr.done) {
      yield peekr.value;
      peekr.advance();
    }
  }
}

function __roundRobin(sources, step = 1, start = 0) {
  return __interleave(sources, byPosition, {
    start,
    step
  });
}

exports.__roundRobin = __roundRobin;
const roundRobin = /*#__PURE__*/iterableCurry(__roundRobin, {
  variadic: true,
  minArgs: 0,
  maxArgs: 2,
  validateArgs: /*#__PURE__*/makeValidateArgs('roundRobin')
});
exports.roundRobin = roundRobin;