type-challenges-judge

Type Challenges Judge

Problems

Progress

Ranking

Flatten

提出詳細

type Flatten<T extends readonly unknown[], Acc extends readonly unknown[] = []> =
  T extends [infer Head, ...infer Tail]
  ? Head extends unknown[]
    ? Flatten<[...Head, ...Tail], Acc>
    : Flatten<Tail,[...Acc, Head]>
  : Acc

提出日時	2023-09-14 03:14:37
問題	Flatten
ユーザー	sankantsu
ステータス	Accepted

テストケース

import type { Equal, Expect } from '@type-challenges/utils'

type cases = [
  Expect<Equal<Flatten<[]>, []>>,
  Expect<Equal<Flatten<[1, 2, 3, 4]>, [1, 2, 3, 4]>>,
  Expect<Equal<Flatten<[1, [2]]>, [1, 2]>>,
  Expect<Equal<Flatten<[1, 2, [3, 4], [[[5]]]]>, [1, 2, 3, 4, 5]>>,
  Expect<Equal<Flatten<[{ foo: 'bar'; 2: 10 }, 'foobar']>, [{ foo: 'bar'; 2: 10 }, 'foobar']>>,
]