public function regexExtract($pattern, $options = '')
    {
        // Define the array that will be filled by preg_match().
        $matches = [];

        // Ensure the options contain the "u" modifier.
        if (!$this->newSelf($options)->contains('u')) $options .= 'u';

        // Build the expression
        $expression =
            $this->regexDelimiter.
            $pattern.
            $this->regexDelimiter.
            $options
        ;

        // Run the expression
        $result = preg_match($expression, $this->scalarString, $matches);

        // If no errors return the $matches array
        if ($result !== false) return $this->newSelfs($matches);

        // Otherwise throw with last known PCRE Error.
        throw new PcreException();
    }