Add before and after macros

[shugyosha89]

These are some macros to easily insert items into a Collection before or after an existing item.

You can can insert after a given value in the Collection, or after a given key:

collect(['zero', 'two', 'three'])->insertAfter('zero', 'one');
// Collection contains ['zero', 'one', 'two', 'three']

collect(['zero', 'two', 'three'])->insertAfterKey(0, 'one');
// Collection contains ['zero', 'one', 'two', 'three']

Optionally a key for the new item can also be given:

collect(['zero' => 0, 'two' => 2, 'three' => 3]->insertAfter(0, 5, 'five');
// Collection contains ['zero' => 0, 'five' => 5, 'two' => 2, 'three' => 3]

collect(['zero' => 0, 'two' => 2, 'three' => 3]->insertAfterKey('zero', 5, 'five');
// Collection contains ['zero' => 0, 'five' => 5, 'two' => 2, 'three' => 3]

insertBefore and insertBeforeKey work the same way, but they insert before the item:

collect(['zero', 'two', 'three'])->insertBefore('two', 'one');
// Collection contains ['zero', 'one', 'two', 'three']

Please take a look, thanks!

[freekmurze]

Thanks!