> It is an old language, and there are a few features that could probably be left out like the OOP-related features, and some libraries in the ecosystem over-complicate things like in Haskell.
If one can stand a language that is just a little bit older, there is always Standard ML. It is like OCaml, but perfect!
I love standard ml (I'm currently writing a compiler for it), but it's far from perfect. There are weird special cases in the language definition like the ad-hoc overloading between int and real, or the annoying value restriction. Records also feel half-baked, with no support for updating fields or for partially-specified records where the full set of fields is not known
While it's not yet standard nearly all Standard ML implementations support what has become known as "Successor ML" [0]. A large subset of Successor ML is common to SML/NJ, MLton, Poly/ML, MLKit and other implementations.
That includes record update syntax, binary literals, and more expressive patterns among other deficiencies in Standard ML.
For me the two big remaining issues are:
1) There's only limited Unicode support in both the core language and the standard library. This is a big issue for many real-world programs including these days the compilers for which SML is otherwise a wonderful language.
2) The module system is a "shadow language" [0] which mirrors parts of SML but which has less expressiveness where modules cannot be treated as first-class values in the program. Also if you define infix operators in a module their fixity isn't exported along with the function type. (Little annoyance that gets me every time I am inclined to write Haskell-style code with lots of operators. Though maybe that's just another hint from the universe that I shouldn't write code like that.) Of course, the fix to that would be a fundamentally different language; not a revised SML.
I love SML, and came to OCaml a bit begrudgingly initially just for a larger ecosystem. But, I think the object system gets a unjustly bad wrap. The OCaml object system is dope. It is rarely needed and not the best feature for most use cases, but when you want structurally-typed records, or need open recursion (or need to represent JS objects for the amazing `Js_of_ocaml`), they are a perfect fit.
I far preferred Standard ML when I learned both back in the day, but it was OCaml that won the headspace it seemed.
Ironically probably because it had the "O"bjects in it, "which was the style of the time"... something that has since dropped off the trendiness charts.
If one can stand a language that is just a little bit older, there is always Standard ML. It is like OCaml, but perfect!