[laurentl]

I went through the same question a few months ago. I settled on OCaml.

Pros: it's reasonably straightforward to pick up, and it shines as a functional programming language. There are some good learning resources out there, e.g. Real World OCaml. I like the syntax much more so than, say, Haskell, but YMMV.

Cons: a very small std library, meaning you need to go with one of several 'battery' libraries. Feels less polished than mainstream languages in terms of user-friendliness (to be fair my reference point on both subjects is Python). A whiny post on these shortcomings: https://medium.com/@laurent.leconte/advent-of-code-2019-its-... (hopefully this gets me motivated enough to finish the follow-up post)