Proposal: Enumerate and IntRange

[lucasteles]

Useful for when we are working with restrict numeric values

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<T>, Enumerate<F>> | T

So it can be used:

type ValidAmount = Enumerate<4> //  0 | 1 | 2 | 3
type WeekDay = IntRange<1, 7> // 1 | 2 | 3 | 4 | 5 | 6 | 7

[sindresorhus]

Related to #123

[sindresorhus]

This is accepted.