Travel should have specialized functions about hex_math

[leftiness]

Okay. I just deleted the code to do this. It's really simple, but it's basically copy-paste eight times (east, southeast, etc).

I have two things on my mind.

• Macro would eliminate repetition
• #9 mitigates this

It would be an internal macro. Not exported. It would make a travel::east() function out of travel::generic() and Direction::East. Some syntax like travel_fn!(Direction::East) or something. Seems really unnecessary honestly.

Then there's #9. When I do that, it'll change the code from travel(point, Direction::East, 5) to point.travel(Direction::East, 5). Yeah, sure, point.east(5) is shorter, but it still feels at least a little better to take the point argument out and make it the callee.

Is it worth really copy-paste code to save a few characters? Maybe not. If I do a lot of travel() function calls, I could use Direction::* in that scope, so it would be point.travel(East, 5). That's surely no problem.

I'll come back to this after #9 and see what I think then.

[leftiness]

Unnecessary.