rangeof.ts

//https://github.com/microsoft/TypeScript/issues/26223#issuecomment-674514787 :pray:
export type RangeOf<N extends number> = Partial<TupleOf<unknown, N>>['length'];

type BuildPowersOf2LengthArrays<
	N extends number,
	R extends never[][]
> = R[0][N] extends never
	? R
	: BuildPowersOf2LengthArrays<N, [[...R[0], ...R[0]], ...R]>;

type ConcatLargestUntilDone<
	N extends number,
	R extends never[][],
	B extends never[]
> = B['length'] extends N
	? B
	: [...R[0], ...B][N] extends never
	? ConcatLargestUntilDone<
			N,
			R extends [R[0], ...infer U] ? (U extends never[][] ? U : never) : never,
			B
	  >
	: ConcatLargestUntilDone<
			N,
			R extends [R[0], ...infer U] ? (U extends never[][] ? U : never) : never,
			[...R[0], ...B]
	  >;

type Replace<R extends any[], T> = { [K in keyof R]: T };

type TupleOf<T, N extends number> = number extends N
	? T[]
	: {
			[K in N]: BuildPowersOf2LengthArrays<K, [[never]]> extends infer U
				? U extends never[][]
					? Replace<ConcatLargestUntilDone<K, U, []>, T>
					: never
				: never;
	  }[N];