Funct multi file function merger to single file

merger.php

<?php

use Symfony\Component\Finder\Finder;
use Symfony\Component\Finder\SplFileInfo;

require_once __DIR__ . '/vendor/autoload.php';

$groups = ['Collection', 'String', 'Objects'];

foreach ($groups as $groupName) {
    $lowGroupName = strtolower($groupName);

    $root = realpath(__DIR__ . '/../funct/src');

    $finder = new Finder();
    $finder->in($root . '/CodeBlocks/' . $groupName)->name('*.php')->files();

    $files = [];

    /** @var SplFileInfo $splFile */
    foreach ($finder as $splFile) {
        $files[] = [
            'real_path' => $splFile->getRealPath(),
            'filename'  => $splFile->getFilename(),
            'content'   => $splFile->getContents()
        ];
    }

    $functions = [];
    foreach ($files as $file) {
        $tokens               = [];
        $startCapturingTokens = false;
        $functionNameTokens   = 2;
        $functionName         = null;

        foreach (token_get_all($file['content']) as $token) {
            if (is_array($token)) {
                if ($token[0] === T_DOC_COMMENT) {
                    $startCapturingTokens = true;
                }

                if ($functionNameTokens === 0) {
                    $token[1]           = str_replace($lowGroupName . '_', '', $token[1]);
                    $functionName       = $token[1];
                    $functionNameTokens = false;
                }

                if ($token[0] === T_FUNCTION) {
                    $functionNameTokens--;
                }

                if ($functionNameTokens === 1 && $token[0] === T_WHITESPACE) {
                    $functionNameTokens--;
                }

                if ($token[0] === T_STRING) {
                    $token[1] = str_replace($lowGroupName . '_', '', $token[1]);
                }
            }

            if ($startCapturingTokens) {
                $tokens[] = $token;
            }
        }

        $code = '';
        foreach ($tokens as $token) {
            if (is_array($token)) {
                $code .= $token[1];
            } else {
                $code .= $token;
            }
        }

        $functions[$functionName] = $code;
    }

    ksort($functions);

    $template = [
        '<?php',
        '',
        'namespace Funct\\' . $groupName . ';',
        '',
        implode(PHP_EOL . PHP_EOL, $functions)
    ];

    $file = $root . '/' . $groupName . '.php';

    file_put_contents($file, implode(PHP_EOL, $template));
}