I would like to write some tests which check arithmetic on negative numbers but then I realized that I do not have a Unary Expression class in my AST with a - Operator because the project description does only list those four operators:

’*’ | ’&’ | ’sizeof’ | ’!’

So what about negative numbers?

What about 0 - someNumber? That should work if I am not wrong.

0 - someNumber

Yes, that does work, but I’m still not sure if something like (-1) * 6 should be possible or not.

(-1) * 6

The parser and the reference support unary negation. But we do not expect your code to handle the unary minus.

Regarding negative numbers: The result of (0-1)*6 should be -6.

(0-1)*6

-6