Use enum for directions

As stated in the docs,
> The directions are numbered as `1 => -x, 2 => +x, 3 => -y, 4 => +y, 5 => -z, 6 => +z`.

As a Java developer, I would want to use an enum instead. This way, the direction would be clear to a reader without reading the docs first. Also, this would be safer, as it doesn't allow other values than 1 and 2 for one dimension, 1 to 4 for two, ...
I just checked, and it seems like enums in Julia work like enums in Java.

Would this be a good idea here (apart from the fact that a lot of code would need to be refactored) and if not, why?