274 - Integers Comparator

[koSakano]

enum Comparison {
  Greater,
  Equal,
  Lower,
}

type Comparator<A extends number, B extends number> = A extends B ? Comparison.Equal : Iterate<A, B, []>;

type Iterate<A extends number, B extends number, Tuple extends any[]> =
  Tuple['length'] extends A ? ( // A is the smallest magnitude number and is positive
    IsNegative<B> extends true ? Comparison.Greater : Comparison.Lower
  ) : Tuple['length'] extends B ? ( // B is the smallest magnitude number and is positive
    IsNegative<A> extends true ? Comparison.Lower : Comparison.Greater
  ) : `-${Tuple['length']}` extends `${A}` ? ( // B is smallest magnitude number and is negative
    IsNegative<B> extends true ? Comparison.Greater : Comparison.Lower
  ) : `-${Tuple['length']}` extends `${B}` ? ( // A is smallest magnitude number and is negative
    IsNegative<A> extends true ? Comparison.Lower : Comparison.Greater
  ) : Iterate<A, B, [null, ...Tuple]>;

type IsNegative<B extends number> = `${B}` extends `-${infer _}` ? true : false;