RoaringBitmap

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 ?. The method is implemented using count trailing zeros intrinsic in the dense container so it is very performant for dense bitmaps https://github.com/RoaringBitmap/RoaringBitmap/blob/d2c6c3bc... Maybe this can be ported to the rust lib as well.

> If you want to be my hero, find a way to fix this problem: https://maxdemarzi.com/2023/01/09/death-star-queries-in-grap... Let me (try to) be your hero, Marzi. (Insert favorite reference to famous cheezy pop music song, if you like.) Couldn't you use GraphBLAS algorithms, like they do in RedisGraph (which supports Cypher, btw) to fix that problem with "death star" queries? Those algorithms are based on linear algebra and matrix operations on sparse matrices (which are like compressed bitmaps on speed, re: https://github.com/RoaringBitmap/RoaringBitmap ). The insight is that the adjacency list of a property-graph is actually a matrix, and then you can use linear algebra on it. But it may require the DB is built bottom up with matrices in mind from the start (instead of linked lists like Neo4j does). Maybe your double array approach in Ra

Sidetracking a bit the conversation. What a coincidence that the author (Lemire) is also represented on Today's #1 "Ask HN: What are some cool but obscure data structures you know about?" as he is the main contributor of RoaringBitmap https://github.com/RoaringBitmap/RoaringBitmap and one of the main authors of the data structure.

The implicit grid data structure from there is a personal favorite of mine. I used it in a game once and it performed incredibly well for our use case. It's a bit too complicated to totally summarize here, but it uses a bit per object in the scene. Then bit-wise operations are used to perform quick set operations on objects. This data structure got me generally interested in algorithms that use bits for set operations. I found the Roaring Bitmap github page has a lot of useful information and references wrt this topic: https://github.com/RoaringBitmap/RoaringBitmap

> Nothing but dirty FUD by someone whose Java skills are at best Junior level. Lamire (the author of the blog post) is well know as the author of https://github.com/RoaringBitmap/RoaringBitmap which is in widespread use.

There are some operations that can be efficiently done over the compressed data itself. Compressed bitmap is a good motivating example (and I really liked Roaring Bitmap [1]). But I guess that such efficiency is very specific to the exact operation and the viability of general compressed operation is unclear; as a related example, fully homomorphic encryption (FHE) that does the same over ciphertexts is still an active research problem. [1] https://github.com/RoaringBitmap/RoaringBitmap