ArrowFunctionExpression example

private function parseArrow()
    {
        $stream = $this->parser->getStream();

        // short array syntax (one argument, no parentheses)?         if ($stream->look(1)->test(/* Token::ARROW_TYPE */ 12)) {
            $line = $stream->getCurrent()->getLine();
            $token = $stream->expect(/* Token::NAME_TYPE */ 5);
            $names = [new AssignNameExpression($token->getValue(), $token->getLine())];
            $stream->expect(/* Token::ARROW_TYPE */ 12);

            return new ArrowFunctionExpression($this->parseExpression(0), new Node($names), $line);
        }

        // first, determine if we are parsing an arrow function by finding => (long form)         $i = 0;
        if (!$stream->look($i)->test(/* Token::PUNCTUATION_TYPE */ 9, '(')) {
            return null;
        }
        ++$i;
        while (true) {
            // variable name             ++$i;