type-samurai/src/sort.d.ts

Advanced utility types for Typescript

import { Decrement } from "./decrement";
import { IsEqual } from "./equal";
import { IsGreaterThan } from "./greater-than";
import { Increment } from "./increment";
import { IsLowerOrEqual, IsLowerThan } from "./lower-than";
import { Swap } from "./swap";

type _SortSingle<
  Result extends readonly number[],
  PivotIndex extends number,
  CurrentIndex extends number
> = IsEqual<PivotIndex, CurrentIndex> extends true
  ? Result
  : Increment<CurrentIndex> extends infer NextCurrentIndex extends number
  ? _SortSingle<
      IsGreaterThan<Result[CurrentIndex], Result[NextCurrentIndex]> extends true
        ? Swap<
            Result,
            CurrentIndex,
            NextCurrentIndex
          > extends infer NewResult extends readonly number[]
          ? NewResult
          : Result
        : Result,
      PivotIndex,
      NextCurrentIndex
    >
  : never;

type _Sort<
  T extends readonly number[],
  CurrentIndex extends number
> = IsLowerOrEqual<CurrentIndex, 0> extends true
  ? T
  : _SortSingle<T, CurrentIndex, 0> extends infer NewT extends readonly number[]
  ? _Sort<NewT, Decrement<CurrentIndex>>
  : T;

/**
 * Sorts a tuple of numbers in ascending order.
 * @example
 * ```ts
 * // [1, 2, 3]
 * type T0 = Sort<[3, 2, 1]>;
 * 
 * // [-1, 0, 1]
 * type T1 = Sort<[1, -1, 0]>;
 * ```
*/
export type Sort<T extends readonly number[]> = IsLowerThan<
  T["length"],
  2
> extends true
  ? T
  : _Sort<T, Decrement<T["length"]>>;