Learn Programming with OCaml
111 by elvis70 · · usr.lmf.cnrs.fr · 43 comments
I do really wonder what it would be like to learn to program for the first time with OCaml.
I remember learning to use OCaml in a properly functional way after so long writing code in C and it was really miserably painful trying to change how I thought about algorithms. I eventually got over the hill and it changed how I write code in C (for the better?), but I do wonder if it would have been easier to have learned OCaml as a first language instead.
I did so! (quirks of the path I took in the French educational system)
I went through a book similar to the one above, with no internet connection. The first few weeks were rough: I did not quite know what a type was and the compiler error messages were unforgiving and hard to understand without that context. But, once I grokked the core ideas (a proper idea of what could be done with recursion took much longer), things went surprisingly smooth. I definitely credit it with making me a better programmer.
It's a good language to learn programming. Very simple semantics. But ultimately, you need to learn different paradigms, I think the order doesn't matter, they'll still be an element of surprise.
Also OCaml lets you write imperative code if you wish so. So you can learn the different paradigms within the same language.
When I first learned to program at university we were taught Haskell. That was 15 years ago and I've not really programmed anything in Haskell since, instead I've racked up years coding professionally in pretty much all the major imperative languages.
I'm aware of why Haskell is not practical as a production language for most companies, but I have to say I've never really coded in anything else that feels as "neat" and it's a shame. Every other language feels like it has some idiosyncratic scaffolding one has to learn, reminding you that you're constrained by how computer hardware works, rather than just expressing an algorithm in terms of inputs and outputs.
I would say it has made me a better coder, I've still kept a preference for keeping data immutable, copyable and abstracting complexity into easily testable functions over classes with unobservable mutable state.
> Learn Programming with OCaml
Lately, I keep asking myself, do I need to learn this new thing, should I force myself to learn this thing, LLMs know it anyways and so on.
So (asking genuinely), should we learn these things?
You can also learn for your own amusement, and solely for the fun of comprehension; a lot of mathematician were driven by this. It's a shame current social value places so much utilitariaism on learning.
This. The question can be seen like “should I learn to solve sodoku, if a computer can do it better?”
As always, it is good to be aware that many people are too anxious about more existential issues to comfortably an consistently expend effort on intellectually-taxing tasks that aren't perceived as directly related to their survival. If it's an issue with social values, it's less of one related to learning as it is to perpetuating artificial scarcity.
This ^
My experience with OCaml has transformed how I think about programming and complex system design. This may also be true if you learn any other functional programming language, but OCaml is easy and flexible which makes it good imo as a door towards the more formal part of comp sci. Even for steering an LLM I think this might help.
My experience with lisp was exactly that: it completely changed how I think about programming, but much more, how I think about systems and engineering. (I learned it through SICP)
Michael Clarkson teaches OCaml at Cornell. I highly recommend his free course materials [1]. He’s an excellent educator. Learning functional programming paradigms had a major influence on how I design programs. Clarkson also taught snippets from the Pragmatic Programmer, which was equally influential (as it has been for many many others) [2].
[1] https://www.cs.cornell.edu/courses/cs3110/2025sp/
[2] https://pragprog.com/titles/tpp20/the-pragmatic-programmer-2...
LLM + static types is a winning combo. And if you want to be serious with what you do with your LLM, you need to understand the output to some extent.
That being said, you may as well use Rust. The extra complexity of manual memory management and Rust idiosyncracies are easily dealt with by the LLM.
You could have asked this question 10 years ago, long before llms. It's not like you'd realistically would get an ocaml job back then when there's so few of them, so why bother?
The answer is still the same as well, people learn ocaml either because they enjoy it, or because learning a functional language makes them a better programmer overall and teaches your brain to approach a problem in a different way.
Should you learn history if it is already written in a book? Should you live if others are already living?
For most people, history is trivia.
Why learn an instrument when you can just press play?
Why does anyone have any hobbies?
Cultural inertia: until recently, you couldn't just press play and get even a wide selection of music: for most of history, if you wanted music, you had to make it or hire someone to do it for you.
More recently, you had to go to the store and buy it, which meant you didn't have much variety.
Today, learning an instrument is for social status, inheriting the shine of the past, where music was rare and costly. The reason to learn an instrument today is because the former situation was romanticized.
It'll probably take a generation before people ease into guilt-free enjoying infinite, fully generated music.
Outsourcing all the thinking to machines may have consequences you might not like.
An oblique explanation: https://croissanthology.com/earring
Seeing that you already know programming, I'd say it'd be less risky for you. But the only reason you're able to pilot an LLM to do programming for you, is because you understand programming and architecture.
But what about the future generations skipping the step of learning the OCaml's, the C's, the Python's...? It's quite concerning.
Oh by the way, yes. Learn OCaml!
I would sharpen my software engineering skills rather than coding / programming skills.
LLMs know it anyways?
Hhhmmmmm
I mean if you want to let llms do everything for you go ahead. Wall-e implications aside, it seems like a great self centric life.
What the hell else do you have to do?!
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Why is the PDF smaller than the Epub file?
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OCaml is the LLM secret weapon right now. They are better at writing it than they are any other language.* That’s all I have to say about it.
* Other “pure” hindley-milner languages are tied but among them ocaml has some particular strengths that I’m sure others will discuss.
Two genuine questions. (1) Why not Rust? (2) Why not Haskell?
(I have my own answers, but I'd love to hear yours, too.)
1. Compile times. OCaml compiles very quickly (think Go) and this gives you a fast feedback loop. It lets the LLM rip through the implementation.
2. OCaml has an idiomatic approach of using interface files for all modules that can be accessed outside their libraries, and interface files give LLMs a great précis of exactly what is wanted. They then just have to follow the types and fill in the blanks to get the implementation. It's nearly the perfect use case.
Both force the model to reason about types too much. The more constrained type system plus global inference merely holds them to what they already wrote, with very fast feedback.
Rust is fine if you need it but most things don’t and ocaml has more convenient abstractions for “regular” work. If you need rust you need rust but ocaml isn’t that far off in perf.
Haskell type system is too expressive, it itself becomes a place for the agent to make mistakes and get bogged down.
(1) complexity
(2) performance
Did you also compare F#?
Flamebait aside, has this been studied for real ? Curious how you would rate that...
Yes I contributed code to a paper on it this spring. It’s hard to measure and “studying” it just means feeding money into frontier models. If anyone has a few billion tokens for a couple masters students hmu so they can get it published.
[1] https://www.youtube.com/watch?v=9Cswiqrq6So