Edit: but in this case, apparently the book was written for a course at Cornell where they teach both functional and imperative programming using the same language.

So my guess would be less that Haskell is not these things (nor couldn't it be) but rather that OCaml has had the external forces necessary to optimise for these things above all else.

Plus, though both languages allow defining new infix operators, ocaml coders are much more restrained about it than haskellers, and I hate having to figure out what >>>>$=<<< does when it shows up in code.

- Pragmatism: The ocaml community has a stronger focus on practical real projects. This is shown by the kind of packages available on the ecosystem and the way those packages are presented. (A number of Haskell packages I've tried to use often seen to be primarily intellectual pursuit with little documentation on actually using them).

- Simplicity: Haskell does have some amazing features, but it has so many different ways to do things, so many compiler flags, code can look vastly different from one codebase to another. It's kind of the c++ of FP. Ocaml is definitely more cohesive in its approach.

Tooling: last I used Haskell the whole ecosystem was pretty rough, with two package managers and a lot of complexity in just setting up a project. Ocaml is not at the level of rust or other modern languages, but is definitely a stop above I'd say.

Everyone talks a good line about more powerful, expressive programming languages till they need to put in the work. Ten years effort to program like ten people the rest of your life? I'm 69 now, I can see how such an investment pays off.

I moved to OCaml. Studying their library source code is the best intro ever to functional programming, but I felt your "all the way" pull and switched to Haskell. (Monads make explicit what a C program is doing anyway. Explicit means the compiler can better help. What it comes down to is making programming feel like thinking about algebra. This is only an advantage if one is receptive to the experience.)

I'm about to commit to Lean 4 as "going all the way". Early in AI pair programming, I tested a dozen languages including these with a challenging parallel test project, and concluded that AI couldn't handle Lean 4. It keeps trying to write proofs, despite Lean's excellence as a general purpose programming language, better than Haskell. That would be like asking for help with Ruby, and AI assuming you want to write a web server.

I now pay $200 a month for Anthropic Max access to Claude Code Opus 4 (regularly hitting limits) having committed to Swift (C meets Ruby, again not just for macOS apps, same category error) so I could have first class access to macOS graphics for my 3-manifold topology research. Alas, you can only build so high a building with stone, I need the abstraction leverage of best-in-category functional languages.

It turns out that Opus 4 can program in Lean 4, which I find more beautiful than any of the dozens of languages I've tried over a lifetime. Even Scheme with parentheses removal done right, and with far more powerful abstractions.

That being said, Haskell is pretty nice as well but I'd pick OCaml for real world stuff.

One thing that bothered me with both these languages is that people not fluent with FP could write code that isn't idiomatic at all. It's probably a bit harder to do in Haskell.

OCaml is immediate by default instead of lazy, and allows imperative code with side-effects. Both escape hatches from the pure FP world.

So, performance is easier to reason about and you can interact with your side-effecty real world stuff without having to reorganize your whole program around the correct monad.

Most of the time you want your loops to be higher order functions but once in awhile you want to just build a vector from a for loop. OCaml let's you do it without it being a whole intervention.

Do you simply dislike the OCaml syntax or is it some particular quirk?

> the variable scope thing

The what thing? Variables are just lexically scoped, are you referring to shadowing?