StackOverflow 266968 - Hash.php

<?php
/**
 * CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 * @since         2.2.0
 * @license       https://opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Utility;

use ArrayAccess;
use InvalidArgumentException;
use RuntimeException;

/**
 * Library of array functions for manipulating and extracting data
 * from arrays or 'sets' of data.
 *
 * `Hash` provides an improved interface, more consistent and
 * predictable set of features over `Set`. While it lacks the spotty
 * support for pseudo Xpath, its more fully featured dot notation provides
 * similar features in a more consistent implementation.
 *
 * @link https://book.cakephp.org/3.0/en/core-libraries/hash.html
 */
class Hash
{

    /**
     * This function can be thought of as a hybrid between PHP's `array_merge` and `array_merge_recursive`.
     *
     * The difference between this method and the built-in ones, is that if an array key contains another array, then
     * Hash::merge() will behave in a recursive fashion (unlike `array_merge`). But it will not act recursively for
     * keys that contain scalar values (unlike `array_merge_recursive`).
     *
     * Note: This function will work with an unlimited amount of arguments and typecasts non-array parameters into arrays.
     *
     * @param array $data Array to be merged
     * @param mixed $merge Array to merge with. The argument and all trailing arguments will be array cast when merged
     * @return array Merged array
     * @link https://book.cakephp.org/3.0/en/core-libraries/hash.html#Cake\Utility\Hash::merge
     */
    public static function merge(array $data, $merge)
    {
        $args = array_slice(func_get_args(), 1);
        $return = $data;
        $stack = [];

        foreach ($args as &$curArg) {
            $stack[] = [(array)$curArg, &$return];
        }
        unset($curArg);
        static::_merge($stack, $return);

        return $return;
    }

    /**
     * Merge helper function to reduce duplicated code between merge() and expand().
     *
     * @param array $stack The stack of operations to work with.
     * @param array $return The return value to operate on.
     * @return void
     */
    protected static function _merge($stack, &$return)
    {
        while (!empty($stack)) {
            foreach ($stack as $curKey => &$curMerge) {
                foreach ($curMerge[0] as $key => &$val) {
                    $isArray = is_array($curMerge[1]);
                    if ($isArray && !empty($curMerge[1][$key]) && (array)$curMerge[1][$key] === $curMerge[1][$key] && (array)$val === $val) {
                        // Recurse into the current merge data as it is an array.
                        $stack[] = [&$val, &$curMerge[1][$key]];
                    } elseif ((int)$key === $key && $isArray && isset($curMerge[1][$key])) {
                        $curMerge[1][] = $val;
                    } else {
                        $curMerge[1][$key] = $val;
                    }
                }
                unset($stack[$curKey]);
            }
            unset($curMerge);
        }
    }
}