Type annotations?

[maweki]

Up for debate: as we touch up some internal functions and helper methods like I propose in #14, do we want to make mypy-compatible type-annotations while we're at it? If we start from the functions small enough, we might be able to type at least the helper modules.

What do you think?

[kirienko]

TL;DR: that would be great.

Well, from one hand, any systematic approach is always welcome. But from the other hand I would do that with a great caution because it's not always clear where and how some particular function is used. Thank Find Usages, we can always check, but that's a big work. That's why IMO it worth doing, but only for fully understood and reviewed parts of code.