partition() function

将 Iterable/AsyncIterable 分割为两个数组:一个包含所有满足 f 的元素,另一个包含所有不满足的元素。

Signature:

declare function partition<
  A,
  L extends A,
  R extends A = A extends object ? ExcludeObject<A, L> : Exclude<A, L>,
>(f: (a: A) => a is L, iterable: Iterable<A>): [L[], R[]];

Example

partition((a) => a % 2 === 0, [1, 2, 3, 4, 5]); // [[2, 4], [1, 3, 5]]

// with pipe
pipe(
  [1, 2, 3, 4, 5],
  partition((a) => a % 2 === 0), // [[2, 4], [1, 3, 5]]
);

await pipe(
  Promise.resolve([1, 2, 3, 4, 5]),
  partition((a) => a % 2 === 0), // [[2, 4], [1, 3, 5]]
);

// if you want to use asynchronous callback
await pipe(
  Promise.resolve([1, 2, 3, 4, 5]),
  toAsync,
  partition(async (a) => a % 2 === 0), // [[2, 4], [1, 3, 5]]
);

// with toAsync
await pipe(
  [
    Promise.resolve(1),
    Promise.resolve(2),
    Promise.resolve(3),
    Promise.resolve(4),
    Promise.resolve(5),
  ],
  toAsync,
  partition((a) => a % 2 === 0), // [[2, 4], [1, 3, 5]]
);

Try It

see pipe, toAsync

Open Source Code