Function combos

dotenv/stringify_test.ts:111–119

(arr: T[], k: number)

  ];

  function combos<T>(arr: T[], k: number): T[][] {
    if (k === 0) return [[]];
    if (arr.length < k) return [];
    const [first, ...rest] = arr;
    return [
      ...combos(rest, k - 1).map((c) => [first!, ...c]),
      ...combos(rest, k),
    ];
  }

  for (const k of [1, 2, 3]) {
    for (const c of combos(trickyChars, k)) {