Display functions like '+' or '[' as is

Question

When I write code chunk in Rmd-file

```{r}
'+'(3,5)
```

knitr returns html-file as

3 + 5

So it transforms the expression to more common format. How can I disable such transformation to keep expression as is?
In comparison, the same code in Rpres-file is displayed correctly '+'(3,5).

Answer 1

All the credit goes to @rawr, and his comment of "set tidy = FALSE".

This question needed an answer.

```{r, tidy=FALSE}
'+'(3, 5)
```

produces