indexed-collection/src/indexes/CollectionIndex.ts

A zero-dependency library of classes that make filtering, sorting and observing changes to arrays easier and more efficient.

import { ICollectionOption } from '../core/ICollectionOption';
import { KeyExtract } from '../core/KeyExtract';
import { defaultCollectionOption } from '../core/defaultCollectionOption';

import { IndexBase } from './IndexBase';

type KeyTypeArray = ReadonlyArray<unknown>;

type KeyExtractArray<T, KeysT extends KeyTypeArray> = {
  [index in keyof KeysT]: KeyExtract<T, KeysT[index]>;
};

export class CollectionIndex<T, KeysT extends KeyTypeArray> extends IndexBase<T> {
  constructor(keyFn: KeyExtractArray<T, KeysT>, option: Readonly<ICollectionOption> = defaultCollectionOption) {
    super(keyFn, option);
  }

  public getValue(...keys: KeysT): readonly T[] {
    return super.getValueInternal(keys);
  }
}