cartesian.ts

// SOURCE: https://gist.github.com/ssippe/1f92625532eef28be6974f898efb23ef?permalink_comment_id=4612830#gistcomment-4612830
export function cartesian<T>(...all: T[][]): T[][] {
  return all.reduce<T[][]>(
    (results, entries) =>
      results
        .map((result) => entries.map((entry) => result.concat([entry])))
        .reduce((sub, res) => sub.concat(res), []),
    [[]],
  );
}