Doctrine DQL cast function

Cast.php

<?php

use Doctrine\ORM\Query\AST\Functions\FunctionNode;
use Doctrine\ORM\Query\Lexer;
use Doctrine\ORM\Query\Parser;
use Doctrine\ORM\Query\SqlWalker;

class Cast extends FunctionNode
{
    private $expr1;
    private $expr2;

    public function parse(Parser $parser)
    {
        $parser->match(Lexer::T_IDENTIFIER);
        $parser->match(Lexer::T_OPEN_PARENTHESIS);
        $this->expr1 = $parser->ArithmeticExpression();
        $parser->match(Lexer::T_COMMA);
        $this->expr2 = $parser->StringPrimary();
        $parser->match(Lexer::T_CLOSE_PARENTHESIS);
    }

    public function getSql(SqlWalker $sqlWalker)
    {
        $type = trim($this->expr2->dispatch($sqlWalker), "'");
        return sprintf(
            'cast(%s as %s)',
            $this->expr1->dispatch($sqlWalker),
            $type
        );
    }
}

thanks @lyrixx