david wong

Hey! I'm David, the author of the Real-World Cryptography book. I'm a crypto engineer at O(1) Labs on the Mina cryptocurrency, previously I was the security lead for Diem (formerly Libra) at Novi (Facebook), and a security consultant for the Cryptography Services of NCC Group. This is my blog about cryptography and security and other related topics that I find interesting.

OCaml wishlist posted 2 weeks ago

I've been writing (although mostly reading) OCaml on-and-off this last year. It's been quite a painful experience, even though I had some experience with functional languages already (erlang, which I really liked).

I find the language and the experience very close to C in many ways, while at the same time boasting a state of the art type system. It's weird. I think there's a real emphasis on the expressiveness, but little on the engineering. Perhaps this is due to the language not having enough traction in the industry.

So about this, I have two things I'd like to say. The first, is that if you're looking for a somewhat low-level (there's a garbage collector) language you can make a real dent in, OCaml might be the one. It's pretty bare bone, not that many libraries exist, and if they do they are barely usable due to a lack of documentation. My first contribution was a library to encode and decode hexadecimal strings, because I couldn't find one that I could use. That should tell you something.

My second contribution was a tool to build "by example" websites. I used it to make a website to learn OCaml by examples, and another one to learn Nix by example. How cool would it be if people started using it to build a number of "by examples" websites in the OCaml ecosystem :D?

Anyway, I digress, the second thing I wanted to say is: if you're working on OCaml (or want to contribute to a new language), here's my wishlist:

  • a tool like cargo to manage dependencies (& versions), start projects, run tests, etc. Two important things: it should use a real configuration language (e.g. toml, json, yml) and it should work in a convention over configuration model.
  • better integration with vscode. Every time I write or read OCaml I find myself missing rust-analyzer and its integration with vscode. I just want to be able to go to definitions, even in the presence of functors, and easily find the types of things (and see their implementations).
  • being able to run a single test. It is crazy to me that today, you still can't write an inline test and run it. It's the best way to debug or test something.
  • better compiler error messages. I think the lack of a tool like cargo, and this, are the biggest impediment to the language. See this issue for an example.
  • better default for ocamlformat. OCaml is hard to read, some of the reasons are hard to change, but the formatting can be fixed and it really needs some work.
  • a linter like clippy. It's 2022, every project should be able to run an OCaml linter in CI.
  • good documentation for stdlib and 3rd party libraries. Documentation is really subpar in OCaml.
  • a use keyword to import specific values in scope (as opposed to "opening" a whole module in scope)

PS: would someone actually be interested to work on any of these for a grant? There's a number of new-ish companies in the OCaml space that would probably pay for someone to solve these. I guess reach out to me on the contact page if you're interested.

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Hey, I mostly agree with your points here. There's much to improve, especially in build and package management tooling. E.g. https://discuss.ocaml.org/t/obazl-toolsuite-tools-for-building-ocaml-with-bazel/10021/17?u=yawaramin

I have to raise two points though: did https://opam.ocaml.org/packages/hex/ not exist when you were looking for a hex converter? It seems dead simple to use. And the OCaml compile error example you gave basically boiled down to 'we should try to use more colours in compile errors', for which there is a PR, and 'we should print a blank line between each discrete error', which seems pretty easy to do.


I could really not figure out how to use the other one you linked to. Perhaps today I could figure out a way, but I'm not sure, the examples are cryptic to me.

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