Performed using https://github.com/ilevkivskyi/com2ann
This has no actual effect on the codebase as type checkers (still)
support both and negligible effect on runtime performance since
__future__ annotations ameliorates that. Technically, the bytecode would
be bigger for non function-local annotations, of which we have many
either way.
So if it doesn't really matter, why do a large-scale refactor? Simple:
because people keep wanting to, but it's getting nickle-and-dimed. If
we're going to do this we might as well do it consistently in one shot,
using tooling that guarantees repeatability and correctness.
Repeat with:
```
com2ann mesonbuild/
```
Which adds the `use-set-for-membership` check. It's generally faster in
python to use a set with the `in` keyword, because it's a hash check
instead of a linear walk, this is especially true with strings, where
it's actually O(n^2), one loop over the container, and an inner loop of
the strings (as string comparison works by checking that `a[n] == b[n]`,
in a loop).
Also, I'm tired of complaining about this in reviews, let the tools do
it for me :)
Eli Schwartz