type-challenges-solutions/en/medium-zip

[utterances-bot]

Zip

This project is aimed at helping you better understand how the type system works, writing your own utilities, or just having fun with the challenges.

https://ghaiklor.github.io/type-challenges-solutions/en/medium-zip.html

[marked42]

Use composed tuple of two elements for a single type pattern matching with extends keyword.

type Zip<T extends unknown[], U extends unknown[]> = [T, U] extends [[infer T1, ...infer R1], [infer U1, ...infer R2]] ? [[T1, U1], ...Zip<R1, R2>] : []

[ghaiklor]

@marked42 sweet, I didn't think about compound here, thanks for the solution!

[albert-luta]

Followed @marked42 approach and optimized it to use tail recursion

type Zip<
  T extends unknown[],
  U extends unknown[],
  Acc extends [unknown, unknown][] = []
> = [T, U] extends [
  [infer HeadT, ...infer TailT],
  [infer HeadU, ...infer TailU]
]
  ? Zip<TailT, TailU, [...Acc, [HeadT, HeadU]]>
  : Acc;

[JanessaTech]

The compound solution is really smart! @marked42