<?php
/*
* This file is part of the league/commonmark package.
*
* (c) Colin O'Dell <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
declare(strict_types=1);
namespace League\CommonMark\Normalizer;
/***
* Normalize text input using the steps given by the CommonMark spec to normalize labels
*
* @see https://spec.commonmark.org/0.29/#matches
*/
final class TextNormalizer implements TextNormalizerInterface
{
/**
* @var array<int, array<int, string>>
*
* Source: https://github.com/symfony/polyfill-mbstring/blob/master/Mbstring.php
*/
private const CASE_FOLD = [
['µ', 'ſ', "\xCD\x85", 'ς', "\xCF\x90", "\xCF\x91", "\xCF\x95", "\xCF\x96", "\xCF\xB0", "\xCF\xB1", "\xCF\xB5", "\xE1\xBA\x9B", "\xE1\xBE\xBE", "\xC3\x9F", "\xE1\xBA\x9E"],
['μ', 's', 'ι', 'σ', 'β', 'θ', 'φ', 'π', 'κ', 'ρ', 'ε', "\xE1\xB9\xA1", 'ι', 'ss', 'ss'],
];
/**
* {@inheritdoc}
*/
public function normalize(string $text, $context = null): string
{
// Collapse internal whitespace to single space and remove
// leading/trailing whitespace
$text = \preg_replace('/\s+/', ' ', \trim($text));
if (!\defined('MB_CASE_FOLD')) {
// We're not on a version of PHP (7.3+) which has this feature
$text = \str_replace(self::CASE_FOLD[0], self::CASE_FOLD[1], $text);
return \mb_strtolower($text, 'UTF-8');
}
return \mb_convert_case($text, \MB_CASE_FOLD, 'UTF-8');
}
}