Maybe it's improved, but I was very disappointed to find agents constantly tripping over significant white space with Elm (Claude Code). Always struck me as strange since they are very proficient with python... and Elm has been one of the most stable modern languages (so stable that people complain about it never changing!). I think the last time I tried was a year ago though, so I assume it has improved.
LLMs are way past that, Claude Code can very competently write Elm code now, for example.
I started working with Elm in production again about a year ago and have bounced back and forth between codex and Claude code and haven’t noticed whitespace problems, so I would conclude it’s better but of course your mileage may vary
> I think the last time I tried was a year ago though, so I assume it has improved.
I noticed that coding agents seemed to get pretty good around 2025 Oct/Nov.
If it's improved? My experience with Nickel-lang (probably as not-in-training-data as Elm) is coding agents have improved with this compared to last time I tried.