macroces.php

<?php

use Illuminate\Support\Collection;

Collection::macro('crossMerge', function (Collection $collection) {
    return $this->reduce(function (Collection $result, $item) use ($collection) {
        $result->push($item);
        if ($collection->isNotEmpty()) {
            $result->push($collection->shift());
        }
        return $result;
    }, new Collection())->concat($collection);
});

Collection::macro('paginate', function ($perPage = 25, $pageName = 'page', $currentPage = null) {
    $currentPage = $currentPage ?: \Illuminate\Pagination\Paginator::resolveCurrentPage($pageName);
    $currentPage = $currentPage ?: 1;

    return new \Illuminate\Pagination\LengthAwarePaginator(
        $this->forPage($currentPage, $perPage)->values(),
        $this->count(),
        $perPage,
        $currentPage,
        ['path' => \Illuminate\Pagination\Paginator::resolveCurrentPath()]
    );
});