Dzmitry Misiuk (Aug 01 2026 at 10:30): Dzmitry Misiuk (Aug 01 2026 at 10:30):Planning to take List.join_map : List(a), (a -> List(b)) -> List(b) from #9596 — flat-map / concat-map. I'd implement it as a List builtin (composing List.join + List.map), matching the tracked signature. Shout if you'd rather see it as an Iter helper instead.
Aurélien Geron (Aug 01 2026 at 10:39):That's great, this is one of the last builtins I'm missing in the Exercism exercises.
Shouldn't almost every List function also be available in Iter? E.g., join, join_map, intersperse, min, max, etc. Edit: actually, many already are, the list grew since I last looked! :smile:
Dzmitry Misiuk (Aug 01 2026 at 11:33):Glad it helps the Exercism track! And yeah — Iter parity seems a reasonable direction; happy to look at filling the remaining Iter gaps as a follow-up if the maintainers want it.
Dzmitry Misiuk (Aug 01 2026 at 13:33):PR is up: https://github.com/roc-lang/roc/pull/10522
Last updated: Aug 12 2026 at 12:35 UTC