Fluture VS hashtable-benchmarks

My name is Aldwin. I'm back-end-leaning full-stack (web-) developer with over 13 years of full time professional experience at various software development agencies. Besides that, I have years of hobby-programming and open-source experience, with Fluture[1] being my most well-received.

I've been leading small teams for the last eight years, focusing on developer enabling work such as process management, devops, software architecture, and coaching.

I'm very passionately in particular about functional programming, and I'm hoping to coach teams when it comes to the cross-over between functional programming and software architecture - something a lot of developers who are new to FP struggle with.

Although I have been involved in a huge variety of software types, I'm particularly well-experienced when it comes to real-time, offline-first web-applications and real-time data processing.

[1]: https://github.com/fluture-js/Fluture

I think that it is fine to code perfectly functional apps using TypeScript with React Native and React. You will have a huge community to support you with documentation, libraries, and available labor. Yes, the language has a lot of soundness holes and misses a lot of useful features like pattern matching or type classes but, for me, it is a valid trade-off. There are libraries for better FP programming in TypeScript like fp-ts, io-ts, and fluture.

Fortunately, as it has been shown in this article, it’s definitely possible to use functional programming with plain JavaScript. However, if you really want to dive deeper into this paradigm while using JavaScript, you’ll probably want to use some already existing functional libraries such as Sanctuary, Fluture, Ramda and others.

This is great news for functionally-minded libraries such as Ramda, Sanctuary, Fluture, and many more. But it also makes some vanilla JavaScript nicer, for example:

Since the blog post mentioned a PR to replace linear probing with Robin Hood, I just wanted to mention that I found bidirectional linear probing to outperform Robin Hood across the board in my Java integer set benchmarks:

https://github.com/senderista/hashtable-benchmarks/blob/mast...

https://github.com/senderista/hashtable-benchmarks/wiki/64-b...

https://homes.cs.washington.edu/~magda/papers/wang-cidr17.pd...

I'm most interested in developing high-performance database engines in low-level languages, but open to any challenging systems programming project. I've been working in C++ for the last 3 years, but have written nontrivial projects in Rust and Java as well (e.g., https://github.com/senderista/rotated-array-set, https://github.com/senderista/hashtable-benchmarks). I would enjoy using Rust or Zig on a new project, but I consider the project itself to be much more important than the language it's written in. I am not interested in cryptocurrency, adtech, or fintech projects.

Thanks for the details on your benchmarks. I would like sometime to extend BLP to a more generic setting; as I said I think any trick used with RH would also work with BLP. I just used an integer set because that's all I needed for my use case and it was easy to implement several different approaches for benchmarking. As you note, it favors use cases where the hash function is cheap (or invertible) and elements are cheap to move around.

About your question on load factors: no, the benchmarks are measuring exactly what they claim to be. The hash table constructor divides max data size by load factor to get the table size (https://github.com/senderista/hashtable-benchmarks/blob/mast...), and the benchmark code instantiates each hash table for exactly the measured data set size and load factor (https://github.com/senderista/hashtable-benchmarks/blob/mast...).

I can't explain the peaks around 1M in many of the plots; I didn't investigate them at the time and I don't have time now. It could be a JVM artifact, but I did try to use JMH "best practices", and there's no dynamic memory allocation or GC happening during the benchmark at all. It would be interesting to port these tables to Rust and repeat the measurements with Criterion. For more informative graphs I might try a log-linear approach: divide the intervals between the logarithmically spaced data sizes into a fixed number of subintervals (say 4).

I think "bidirectional linear probing" is an underrated approach (and much simpler): https://github.com/senderista/hashtable-benchmarks/blob/master/src/main/java/set/int64/BLPLongHashSet.java

I will probably never get around to porting my bidirectional linear probing integer hash set from Java to C++, but I hope someone can try adapting BLP to general C++ hashmaps and hashsets, because it significantly outperforms Robin Hood in my benchmarks.

https://homes.cs.washington.edu/~magda/papers/wang-cidr17.pd...

I'm most interested in developing high-performance database engines in low-level languages, but open to any challenging systems programming project. I've been working in C++ for the last 2 years, but have written nontrivial projects in Rust and Java as well (e.g., https://github.com/senderista/rotated-array-set, https://github.com/senderista/hashtable-benchmarks). I would enjoy using Rust or Zig on a new project, but I consider the project itself to be much more important than the language it's written in. I am not interested in cryptocurrency, adtech, or fintech projects.