thunderer / Shortcode

        $appendContent = function(array $token) use(&$content) { $content .= $token[1]; };

        while($this->position < $this->tokensCount) {

            while($this->position < $this->tokensCount && false === $this->lookahead(self::TOKEN_OPEN)) {

                $this->match(null, $appendContent, true);

            }

            $isShortcode = $this->lookaheadN(array(self::TOKEN_OPEN, self::TOKEN_STRING));

            $isMarker = $this->lookaheadN(array(self::TOKEN_OPEN, self::TOKEN_MARKER));

            if(false === ($isShortcode || $isMarker)) {

        $appendValue = function(array $token) use(&$value) { $value .= $token[1]; };

        if($this->match(self::TOKEN_DELIMITER)) {

            while($this->position < $this->tokensCount && false === $this->lookahead(self::TOKEN_DELIMITER)) {

                $this->match(null, $appendValue);

            }

            return $this->match(self::TOKEN_DELIMITER) ? $value : false;

        }