+
+ /**
+ * Multi-byte safe implementation of substr_replace where $start and $length are character offset and count rather
+ * than byte offset and counts.
+ *
+ * Depends on mbstring, use default encoding.
+ *
+ * @param string $string
+ * @param string $replacement
+ * @param int $start
+ * @param int|null $length
+ *
+ * @return string
+ * @see substr_replace()
+ */
+ public static function substringReplace(string $string, string $replacement, int $start, int $length = null): string
+ {
+ $string_length = mb_strlen($string);
+
+ $length = $length ?? $string_length;
+
+ if ($start < 0) {
+ $start = max(0, $string_length + $start);
+ } else if ($start > $string_length) {
+ $start = $string_length;
+ }
+
+ if ($length < 0) {
+ $length = max(0, $string_length - $start + $length);
+ } else if ($length > $string_length) {
+ $length = $string_length;
+ }
+
+ if (($start + $length) > $string_length) {
+ $length = $string_length - $start;
+ }
+
+ return mb_substr($string, 0, $start) . $replacement . mb_substr($string, $start + $length, $string_length - $start - $length);
+ }
+
+ /**
+ * Perform a custom function on a text after having escaped blocks matched by the provided regular expressions.
+ * Only full matches are used, capturing group are ignored.
+ *
+ * To change the provided text, the callback function needs to return it and this function will return the modified
+ * version as well after having restored the escaped blocks.
+ *
+ * @param string $text
+ * @param string $regex
+ * @param callable $callback
+ *
+ * @return string
+ */
+ public static function performWithEscapedBlocks(string $text, string $regex, callable $callback): string
+ {
+ // Enables nested use
+ $executionId = random_int(PHP_INT_MAX / 10, PHP_INT_MAX);
+
+ $blocks = [];
+
+ $text = preg_replace_callback($regex,
+ function ($matches) use ($executionId, &$blocks) {
+ $return = '«block-' . $executionId . '-' . count($blocks) . '»';
+
+ $blocks[] = $matches[0];
+
+ return $return;
+ },
+ $text
+ );
+
+ $text = $callback($text) ?? '';
+
+ // Restore code blocks
+ $text = preg_replace_callback('/«block-' . $executionId . '-([0-9]+)»/iU',
+ function ($matches) use ($blocks) {
+ $return = $matches[0];
+ if (isset($blocks[intval($matches[1])])) {
+ $return = $blocks[$matches[1]];
+ }
+ return $return;
+ },
+ $text
+ );
+
+ return $text;
+ }
+}