216 - Slice

[thanhhtse04588]

type Subtraction<
  A extends number,
  B extends number,
  AArray extends unknown[] = LengthToArray<A>,
  BArray extends unknown[] = [],
> = BArray['length'] extends B
  ? AArray['length']
  : AArray extends [infer F, ...infer R]
    ? Subtraction<A, B, R, [...BArray, F]>
    : 'A must greater than B'

type SliceWithPositiveNumber<
  Arr extends number[],
  Start = 0,
  End = Arr['length'],
  Left extends unknown[] = [],
  T extends unknown[] = [],
> = Arr extends [infer F, ...infer R extends number[]]
  ? Start extends number
    ? GreaterThan<Start, Left['length']> extends true
      ? SliceWithPositiveNumber<R, Start, End, [...Left, F]>
      : End extends number
        ? GreaterThan<End, Left['length']> extends true
          ? SliceWithPositiveNumber<R, Start, End, [...Left, F], [...T, F]>
          : T
        : never
    : never
  : T

  type Slice<
    Arr extends number[],
    Start extends number = 0,
    End extends number = Arr['length'],
    Length extends number = Arr['length'],
  > = SliceWithPositiveNumber<
    Arr,
    `${Start}` extends `-${infer S extends number}`
      ? Subtraction<Length, S>
      : Start,
    `${End}` extends `-${infer E extends number}`
      ? Subtraction<Length, E>
      : End
  >