Following up on the Haskell benchmark, the OCaml benchmark, the Python benchmark, the ReScript benchmark, the Ruby benchmark, the Elixir benchmark, and the Java benchmark, I ran the same AoC 2025 Days 1–5 setup in Elm.
Elm is the most niche language in this series. It's a pure functional language that compiles
to JavaScript, has no native CLI story, and sees relatively little use outside its frontend
niche. Each model received a pre-built scaffold — run.mjs, elm.json, and a
Day00.elm template — that compiles and runs Elm modules via Node.js. The question was
whether models would handle Elm's strict type system, lack of escape hatches, and unfamiliar
idioms (e.g. Debug.log for output, Platform.worker for headless programs).
The answer: every single one of them did.