[ms013]

I assume you were just not interested in passing the state around to the functions that needed it, and preferred the fact that the state monad hides that plumbing for you via bind and return. It's worth noting that there exist Ocaml libraries that provide the same operators and even similar do notation syntax that desugars to bind/return operators (via PPX).

Ocaml does tend to be more verbose than Haskell - it's just the nature of the language syntax. E.g., in Ocaml, one says (fun x -> x+1) vs (\x -> x+1). Similarly, ocaml is cursed by the excessive "in"'s that accompany let bindings. "Let .. in let .. in let ...". That can get annoying.

Interestingly, I had the opposite experience with a commercial compiler project. Haskell's syntactic cleverness (monadic syntax, combinator libraries, etc..) eventually got in the way - it became very difficult to understand what a single line of code actually meant since one had to mentally unpack layers of type abstractions. Migrating to ocaml, the verbosity eventually was more tolerable than the opacity of the equivalent Haskell code once the compiler got sufficiently complex.

My experience may vary from yours. I've been doing Haskell/Ocaml in production for many years, so the pain points I've adapted to are likely different than one working on toy compilers or weekend projects. And no, category theory exposure is not and never has been necessary for understanding Haskell or FP unless one is a PL researcher (and even then, only a subset of PL researchers are concerned with those areas). And one can be quite productive and prolific in Haskell without a deep understanding of monads and monad transformers - the blogosphere has given you the wrong impression if you believe otherwise.

[implicit]

I've done a lot of production Haskell and I've had a similar experience.

In our case, we dealt with it by keeping relatively bare, boring code. We avoided point-free style, crazy combinators like lenses, and complex monad transformer stacks except in the 'plumbing' part of the application that didn't need to change very much.

This paid off in spades as we had a lot of engineers who only ever had to work in the 'porcelain' parts of the application. They got a lot of great work done using abstractions that matched their intuition exactly.

[throwaway7645]

Thanks for the thorough reply and it sounds like you're quite experienced here. Any chance going into more detail with what you do for a living? Do you maintain a compiler for something more mainstream?

[ms013]

I cofounded a company recently that is using code transformation and optimization methods to accelerate data analytics code on special purpose hardware. Our compilation toolchain is all ocaml, and the language that is compiled/transformed/optimized is Python. Prior to this venture, I did similar work - code analysis and transformation, but in that case largely around high performance computing for scientific applications. That tooling was mostly ocaml/Haskell, but not production focused - it was mostly research code.