Could you please clarify how division should be handled? It seems everywhere that we are supposed to work on integers but this test case - diff("(/ x 2)"), "0.5" - introduces floating point numbers and I'm not sure what's the logic behind it.

I found one problem, commented in your translation discussion section!

Thanks for the translation!

I think you should import following in the tests:

use std::collections::{BinaryHeap, VecDeque, HashSet};
use std::cmp::Reverse;

The kata wouldn't let me submit without these (and I wasn't using them in my solution).