Luke Boswell (Nov 08 2024 at 02:23): Luke Boswell (Nov 08 2024 at 02:23):I'm wondering if we should add this to builtins somewhere. This came up while upgrading an app that used Task.loop
loop! : state, (state => Result [Step state, Done done] err) => Result done err
loop! = \state, fn! ->
when fn! state is
Err err -> Err err
Ok (Done done) -> Ok done
Ok (Step next) -> loop! next fn!
seems reasonable!
Agus Zubiaga (Nov 08 2024 at 03:18):I feel like I would just use recursion instead
Luke Boswell (Nov 08 2024 at 03:19):So it was something we needed when we had Task but now we don't?
I thought there was some magic that Task.loop had that prevented alias analysis issues.
Agus Zubiaga (Nov 08 2024 at 03:22):Yeah, using recursion with Task is a little less intuitive, so Task.loop makes sense
Agus Zubiaga (Nov 08 2024 at 03:23):but I’m not sure it adds much in the purity inference world
Agus Zubiaga (Nov 08 2024 at 03:23):If you want, you can share the example and we can compare
Luke Boswell (Nov 08 2024 at 03:25):Yeah, I think you're probably right. I was just translating the basic-cli examples.
I think now is a good time to revisit these and "modernise" them. They were written using the API's we had at the time, but a lot has changed.
Even just going through my AoC examples, roc today feels like a world away from last year.
Last updated: Jun 16 2026 at 16:19 UTC