Inclusive Range

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题目

Recursion depth in type system is one of the limitations of TypeScript, the number is around 45.

We need to go deeper. And we could go deeper.

In this challenge, you are given one lower boundary and one higher boundary, by which a range of natural numbers is inclusively sliced. You should develop a technique that enables you to do recursion deeper than the limitation, since both boundary vary from 0 to 200.

Note that when Lower > Higher, output an empty tuple.

解答

type InclusiveRange<
  Lower extends number,
  Higher extends number,
  C extends any[] = [],
  I = false,
  R extends number[] = []
> = I extends true
  ? C["length"] extends Higher
    ? [...R, Higher]
    : InclusiveRange<Lower, Higher, [...C, 1], true, [...R, C["length"]]>
  : C["length"] extends Lower
  ? InclusiveRange<Lower, Higher, C, true>
  : C["length"] extends Higher
  ? []
  : InclusiveRange<Lower, Higher, [...C, 1], false>;