wikimedia/mediawiki-extensions-Wikibase

<?php
declare( strict_types=1 );

namespace Wikibase\Lib\Store;

/**
 * Interface that contains method for the ItemOrderProvider
 *
 * @license GPL-2.0-or-later
 * @author Noa Rave
 */
interface ItemOrderProvider {

    /**
     * Get order of items in the form [ $ItemIdSerialization => $ordinalNumber ]
     *
     * @return null|int[] An associative array mapping Item ID strings to ordinal numbers.
     *     The order of items is represented by the ordinal numbers associated with them.
     *     The array is not guaranteed to be sorted.
     *     Null if no information exists.
     * @throws ItemOrderProviderException
     */
    public function getItemOrder(): ?array;

}