str-extreme-snake.php

<?php

\Illuminate\Support\Str::macro('extremeSnake', function($value, $delimiter = '_') {
	$pattern = <<<'REGEXP'
        /
        (?<!^) # don't match the beginning of a string
        (
            (?<=[^\p{Lu}])[\p{Lu}\p{M}]+(?=\p{M}?[^\p{Ll}]\p{M}?\p{L}) # string of upper-case (like an abbreviation)
            | (?<=\p{Lu}{2})[\p{Lu}\p{M}](?=\p{M}?\p{Ll}) # the final upper-case in a sequence
            | (?<=[^\p{Lu}])[\p{Lu}\p{M}](?=\p{M}?\p{Ll}) # first upper-case in a capitalized sequence
        )
        /ux
        REGEXP;
	
	$value = preg_replace($pattern, ' $1', trim($value));
	
	return preg_replace('/[^\p{L}0-9]+/u', $delimiter, Str::lower($value));
});