StringFragmentSplitter.php

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<?php
 
declare(strict_types=1);
 
/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */
 
namespace ‪TYPO3\CMS\Core\Utility\String;
 
class ‪StringFragmentSplitter
{
    public const ‪TYPE_RAW = 'raw';
 
    public const ‪TYPE_EXPRESSION = 'expression';
 
    public const ‪FLAG_UNMATCHED_AS_NULL = 1;
 
    protected readonly array ‪$patterns;
 
    public function ‪__construct(‪StringFragmentPattern ...‪$patterns)
    {
        $this->patterns = ‪$patterns;
    }
 
    public function ‪split(string $value, int $flags = 0): ?‪StringFragmentCollection
    {
        $pattern = chr(1) . implode('|', $this->‪preparePatterns()) . chr(1);
        $options = PREG_UNMATCHED_AS_NULL | PREG_OFFSET_CAPTURE | PREG_SET_ORDER;
        if (!preg_match_all($pattern, $value, $matches, $options)) {
            if (($flags & self::FLAG_UNMATCHED_AS_NULL) === self::FLAG_UNMATCHED_AS_NULL) {
                return null;
            }
            return new ‪StringFragmentCollection(‪StringFragment::raw($value));
        }
 
        $collection = new ‪StringFragmentCollection();
        foreach ($matches as $match) {
            // filters string keys (e.g. `expression_a1b2c3d4e5`) from matches, skips numeric indexes
            $types = array_filter(
                array_keys($match),
                static fn(int|string $type) => is_string($type) && $type !== ''
            );
            foreach ($types as $type) {
                $matchOffset = $match[$type][1];
                if ($matchOffset < 0) {
                    continue;
                }
                $matchValue = $match[$type][0];
                // matches contain only pattern matches, but no raw string literals - by comparing the
                // position of the collection with the current offset, missing raw literals are synchronized
                if ($collection->getLength() < $matchOffset) {
                    $gapValue = substr($value, $collection->getLength(), $matchOffset - $collection->getLength());
                    $collection = $collection->with(‪StringFragment::raw($gapValue));
                }
                $collection = $collection->with(‪StringFragment::expression($matchValue));
            }
        }
        // synchronize missing raw string literals
        // (at the end of the given value after previous expression)
        if ($collection->getLength() < strlen($value)) {
            $gapValue = substr($value, $collection->getLength());
            $collection = $collection->with(‪StringFragment::raw($gapValue));
        }
        return $collection;
    }
 
    protected function ‪preparePatterns(): array
    {
        return array_map(
            static fn(‪StringFragmentPattern $pattern) => $pattern->‪compilePattern(),
            $this->patterns
        );
    }
}