import { List } from '../util/List';
import { Inc } from '../number/Inc';
import { Subtract } from '../number/Subtract';
import { ObjectHasKey } from '../object/ObjectHasKey';
import { NumberToString } from '../cast/NumberToString';

/**
 * Decrease the indexes on a numerically indexed object by a given amount.
 */
export type DecIndex<R extends List<any>, N extends number, I extends number = R[0], Acc = { length: R['length'] }> =
  { 0: Acc, 1: DecIndex<R, N, Inc[I], Acc & { [P in NumberToString[Subtract<I, N>]]: R[I] }> }[ObjectHasKey<R, NumberToString[I]>];