After years of hemming and hawing, I have decided to learn OCaml. This post is a quick summary of two things: how I landed on OCaml and what my very first steps have been. The former topic is going to be a vibes-first explanation of my past experience and why I chose OCaml. The latter section is going to be a relatively straightforward account of how I've set up my environment so I can learn OCaml in a way that feels familiar to me.

how I settled on OCaml

The "why a new language" part: I like learning new programming languages, and I've wanted to dive into ML languages for years. My only exposure to this group of languages has been a few school assignments and the first two or three chapters of many programming books. The takeaways from these experiences have been understanding basic syntax and configuring my text editor. There's a level of growth that I think just doesn't come without day-to-day experience, and that's what I'm after.

I've spent years going over the introductory material for Idris, Haskell, and OCaml. Each language has its own specific appeal: I want to write Idris and use dependent types; I want to write Haskell to make up for the Ph.D. I never pursued; I want to write OCaml because there are good reasons I never pursued that Ph.D. I had to use Standard ML for a class once, but as a Philadelphian from the Pennsylvania side I must reject New Jersey.

Ultimately, I picked OCaml. If there is any one thing that swayed me to this, it's a line from the end of this post about OCaml:

Particularly if you what you want is “garbage collected Rust that’s not Go”, OCaml is a good choice.

I like Rust, I don't really like Go. I like Python, and I'm kind of hoping OCaml will feel to me like typed, compiled Python.

my actual first steps with the language and its tooling

Eventually, I'll use OCaml for a project I would normally use Python for: parsing CSVs and printing some summary statistics about the data therein. This is a "first steps" post though. If using utop to get some experience with syntax is crawling, my project is probably closer to walking. I'm just trying to stand on my own right now.

Real World OCaml, the seemingly-standard guide for new OCaml programmers, has been extremely helpful, though I've found it a better fit as a reference rather than a book through which one works linearly. Similarly, this Cornell class seems to be a pretty standard introduction to the language. It seems to cover similar ground as Real World OCaml, but it's always nice to have things worded and presented a little differently.

I like looking to Exercism for practical examples, and this time was no exception. Exercism gave me enough of an example of OUnit to let me write some tests. dune, a (the?) build system for OCaml, seems to fill the role that cargo has in Rust. With dune's command to set up a new project and Exercism's tests as an example, I started working on the exercises referenced on the OCaml homepage. With these resources, I've been able to get into the write-compile-run (or just write-test) loop with which I'm familiar.

conclusion

That's it. I still can't take more than a few steps at a time before stumbling, but I can get to walking from here.