<?php

// {{{ License
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.
// }}}

/**
 * Functional utilities
 *
 * @package   GNUsocial
 * @category  Util
 *
 * @author    Hugo Sales <hugo@fc.up.pt>
 * @copyright 2020 Free Software Foundation, Inc http://www.fsf.org
 * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
 */

namespace App\Util;

use Functional as F;

abstract class Functional
{
    /**
     * Call $func with only abs($count) arguments, taken either from the
     * left or right depending on the sign
     *
     * @param callable $func
     * @param int      $count
     *
     * @return callable
     */
    public static function arity(callable $func, int $count): callable
    {
        return function (...$args) use ($func, $count) {
            if ($count > 0) {
                return call_user_func_array($func, F\take_left($args, $count));
            }
            return call_user_func_array($func, F\take_right($args, -$count));
        };
    }
}