Nick Hallstrom (Feb 16 2023 at 01:22): Nick Hallstrom (Feb 16 2023 at 01:22):Is there some sort of process for deciding what new builtins are added? I'd like to add a zip : List a, List b, (a, b -> c) -> List c function if you guys think it would be a good addition.
Nick Hallstrom (Feb 16 2023 at 01:30):Some others I was thinking about would be maxBy : List a, (a -> Num *) -> Result a [ListWasEmpty] and the equivalent minBy
Nick Hallstrom (Feb 16 2023 at 01:30):Oooh just found this :eyes:
https://github.com/roc-lang/roc/issues/664
Nick Hallstrom (Feb 16 2023 at 01:33):Just found that zip already exists and is called map2. I guess this one could probably at least go in the "Different Names" section of the docs
Richard Feldman (Feb 16 2023 at 02:59):great catch - I'd be happy to accept a PR for a "different names" addition!
Nick Hallstrom (Feb 16 2023 at 03:13):What do you think about the maxBy and minBy additions?
Ron Panduwana (Feb 16 2023 at 03:51):Shouldn't it result List a? What if there are ties?
Ron Panduwana (Feb 16 2023 at 03:58):suggestion: would havingMax/havingMin be a better name?
e.g.
players |> List.havingMax score
vs.
players |> List.maxBy score
Brendan Hansknecht (Feb 16 2023 at 04:45):Why would maxBy return a number in the lambda?
Nick Hallstrom (Feb 16 2023 at 04:47):https://www.scala-lang.org/api/2.12.6/scala/collection/TraversableOnce.html#maxBy[B](f:A=%3EB):A
https://www.scala-lang.org/api/2.12.6/scala/collection/TraversableOnce.html#maxBy[B](f:A=%3EB):A
Here’s some examples from other languages I’m familiar with. I think it makes sense to just return the first element if there are ties instead of returning a list. But ya Brendon, if it returned something like [Gt, Lt, Eq] it would be much better.
Nick Hallstrom (Feb 16 2023 at 04:50):So kind of like a combo of List.sortWith and List.first
Last updated: Jul 26 2025 at 12:14 UTC