protected function getRegex()
    {
        if ($this->regex === null) {
            $this->regex = $this->buildRegex($this->getTokens(), $this->constraints);
        }

        return $this->regex;
    }
protected function getRegex()
    {
        if ($this->regex === null) {
            $this->regex = $this->buildRegex($this->getTokens(), $this->constraints);
        }

        return $this->regex;
    }
protected function getRegex ( ) { if ( $ this -> regex === null ) { $ this -> regex = $ this -> buildRegex ( $ this -> getTokens ( ) , $ this -> constraints ) ; } return $ this -> regex ; }
Gets regex for matching.

@return string
Gets regex for matching .