I'm biased, I preferred it this way before AI. But even so I think there is real merit. Firm guardrails and clear feedback seem to benefit AI.
Anecdotally, the worst AI performance I've seen was with gdscript, which is basically python minus the huge corpus of training data. Best results I'm getting with rust, which is in the opposite end of the strictness spectrum.
I have worked extending the Elm compiler and both Opus 4.6, GPT 5.4 and GLM 5 had no issues both with the Elm compiler (written in Haskell) and my extended Elm.
I didn't see them hallucinate much, not more than on mainstream languages.
The compiler is incredibly helpful because it catches errors and gives clear explanations and the LLM can iterate over it. I’ve also added the elm-review package with the default configuration, which is fantastic for ensuring code quality.
Every single one I ask always happily says yes, and starts claiming C# has local classes (a feature of Java)