Add integer range `IntRange` function

[Brandon McConnell]

It could be useful to match a number between a set of number, which a range function could be useful for.

Definition

type Enumerate<N extends number, Acc extends number[] = []> = Acc['length'] extends N
  ? Acc[number]
  : Enumerate<N, [...Acc, Acc['length']]>;

type IntRange<F extends number, T extends number> = Exclude<Enumerate<Simplify<T>>, Enumerate<F>> | T;

Usage

type CustomRange = IntRange<20, 300>; // -> 20 | 21 | ... many more ... | 300

Disclaimer & credit

This type is inspired (99% copied) from this StackOverflow answer by AlexG, with a slight modification to include the last number in the series (| T). Without this change, IntRange<20, 300> would match 20–299 instead or 20–300.

[Brandon McConnell]

Duplicates #9