protected function parseExpr_PreInc(Expr\PreInc $expr)
{
$var = $this->parseExprNode($expr->var);
$read = $this->readVariable($var);
$write = $this->writeVariable($var);
$this->block->children[] = $op = new Op\Expr\BinaryOp\Plus($read, new Operand\Literal(1), $this->mapAttributes($expr));
$this->block->children[] = new Op\Expr\Assign($write, $op->result, $this->mapAttributes($expr));
return $op->result;
}