Add a method to split the "Arr" and "Collection" arrays conditionally.

[junichimura]

Hello Artisan's.
When you are working with list data, do you ever want to split a single list into multiple lists based on a single list?
This issue is a suggestion to make that happen.

<?php
//There is data in the array as follows
$arr = [1,2,3,4,5,6,7,8,9,10];
//Returns an associative array for a given condition.
$closure = function ($v) {
    $condition = $v % 2 === 0;
    if ($condition) {
        return [
            'even' => $v
        ];
    } else {
        return [
            'odd' => $v
        ];
    }
};

// The name of the new method has not yet been determined. (We'll call it group.)
$groups = \Illuminate\Support\Arr::group($arr, $closure)
/*****
[
    "odd" => [
        1,
        3,
        5,
        7,
        9
    ],
    "even" => [
        2,
        4,
        6,
        8,
        10,
    ]
]
*****/

We considered a "macro" to realize this idea.

<?php
// Arr's Macro
\Illuminate\Support\Arr::macro('group', function ($array, $handler) {
    /* @var \Illuminate\Support\Collection $this*/
    $data = [];
    foreach ($array as $baseKey => $baseValue) {
        $results = $handler($baseValue, $baseKey);
        foreach ($results as $group => $value) {
            $data[$group][] = $value;
        }
    }
    return $data;
});

// Collection's Macro
\Illuminate\Support\Collection::macro('group', function ($handler, $collectChildren = true) {
    /* @var \Illuminate\Support\Collection $this*/
    $data = \Illuminate\Support\Arr::group($this->items, $handler);
    $this->items = $collectChildren ? (new static($data))->map(function ($v) {
        return dump(new static($v));
    }) : $data;
    return $this;
});

By adding "group" to "Collection", you can call the method in succession is possible.

<?php
$collectGroup = (new \Illuminate\Support\Collection($arr))->group($closure);
$arrGroup = (new \Illuminate\Support\Collection($arr))->group($closure, false);

$collectGroup->pull('even');
/*****
[
    "even" => [
        2,
        4,
        6,
        8,
        10,
    ]
]
*****/
$arrGroup->pull('odd');
/*****
[
    "odd" => [
        1,
        3,
        5,
        7,
        9
    ]
]
*****/

With the addition of this "group", you can also retrieve values using extract and list. It is possible.

<?php
extract(\Illuminate\Support\Arr::group($arr, $closure));

$closure = function ($v) {
    return [
        $v % 2 => $v,
    ];
};
$groups = \Illuminate\Support\Arr::group($arr, $closure);
ksort($groups);
list($even, $odd) = $groups;

Finally, I look forward to discussing this proposal with you all.
Thanks to all OSS contributors and this great framework!

[junichimura]

Supplementation.
This proposal is compatible with version 7.x.