I haven't tried roaring bitmaps on this problem yet. I think it's generally fairly dense so that's why I tried dense bitsets first, but it's a fair point. It might still be beneficial to go with a sparse representation depending on the interval lengths for example.
I also didn't have a good way to measure runs from roaring bitmap's Rust API (https://github.com/RoaringBitmap/roaring-rs/issues/274) which makes it hard to track interval duration, but would be interested to compare this approach.
Thats fair, the rust port isn't as feature rich as the original Java library. The Java version has methods for previous/next absent value which i think would solve your issue ?.
I also didn't have a good way to measure runs from roaring bitmap's Rust API (https://github.com/RoaringBitmap/roaring-rs/issues/274) which makes it hard to track interval duration, but would be interested to compare this approach.