Stream: contributing

Topic: Track remaining builtins for the Zig compiler

Luke Boswell (Jun 10 2026 at 04:04):

See https://github.com/roc-lang/roc/issues/9596

It's come up a few times, so I thought I'd ask our LLM friends to sift through all the details I could find and put together a consolidated list of missing builtins for us to coordinate around.

Luke Boswell (Jun 10 2026 at 04:06):

I've locked and pinned the issue so we can limit discussion to Zulip ideas threads or more specific GH Issues.

Luke Boswell (Jun 10 2026 at 04:07):

It would be helpful if you see anything that doesn't look right to let me know... I've tried to compile a lot of detail and almost certainly missed some things

Luke Boswell (Jun 10 2026 at 13:11):

I've made a start on two of these
(1) https://github.com/roc-lang/roc/pull/9599 -- implement Dict with an insertion-ordered hash map
(2) https://github.com/roc-lang/roc/pull/9600 -- all of the remaining Numeric builtins

David Mell (Jun 10 2026 at 17:06):

Shouldn't all the builtins that were suffixed with _checked in the old compiler use _try instead, to be consistent with the change in naming of the to_ conversion functions?

Richard Feldman (Jun 10 2026 at 17:47):

that makes sense to me

Luke Boswell (Aug 25 2026 at 23:40):

I just updated the tracking GH Issue for the remaining builtins -- https://github.com/roc-lang/roc/issues/9596

These are the things remaining from what I can see

• the log API https://github.com/roc-lang/roc/issues/5107
• float approximate equality
• raw Dec conversions
• number parsing
• a few Str and List helpers
• list sorting https://github.com/roc-lang/roc/issues/7006
• some Set helpers

TeaDrinkingProgrammer (Aug 26 2026 at 05:42):

I mistook the log API for a logging API, which I haven't seen discussed much. Is that on the radar?

Luke Boswell (Aug 26 2026 at 05:42):

log or logging?

Luke Boswell (Aug 26 2026 at 05:43):

Logging API -- that sounds like an effect that a platform would provide and be responsible for

Luke Boswell (Aug 26 2026 at 05:44):

There isn't anything in the design for the Roc<->Host ABI (unlike dbg, crash, allocations etc) so I do not think there is any plan to add that.

TeaDrinkingProgrammer (Aug 26 2026 at 05:48):

Logging specifically. Might be nice to do something similar to HTTP, where we have built-ins for "constructing" the log and you can then choose to log using dbg or have the host expose a function to write a logging file for instance.

Luke Boswell (Aug 26 2026 at 05:52):

I'm not tracking anything, would you like to start an #**ideas thread about it?

Jonathan (Sep 03 2026 at 16:24):

I see List.map! has been deferred. I was just needing to map over some things using a db connection. I know I can use for loops (and preallocated destination) but was curious as to why it's been pushed back?

Richard Feldman (Sep 03 2026 at 18:07):

the only reason was just "is there a real use case for this or are we only including it because it's obvious how it would work?"

Richard Feldman (Sep 03 2026 at 18:07):

if you've found a real use case, happy to add it! :smile:

Richard Feldman (Sep 03 2026 at 18:07):

I'm just curious what the use case turned out to be haha

Jonathan (Sep 03 2026 at 18:19):

Just a minor convenience. Wanted to fetch some data for a list of ids: jobs = ids.map!(|id| Query.get_job_data(q, stmt, id)) (I know, not using a batched query)

Jonathan (Sep 03 2026 at 18:22):

You might say that not adding it here is good to discourage N+1 -- fair enough :laughing:

removewingman (Sep 03 2026 at 20:24):

Would it be possible to add List.for_each_try! : List(a), (a => Try({}, err)) => Try({}, err) aswell?

Also just minor convenience, so I can refactor this:

main! = |_args| {
  for line in Stdin.lines!()? {
    Stdout.write!("${line}\n")
  }
  Ok({})
}

Richard Feldman (Sep 04 2026 at 00:50):

seems reasonable! :+1:

Dan G Knutson (Sep 04 2026 at 01:30):

Effectful pure-ish functions like List.map! are also nice for platform-specific pure-ish functions like floating point SIMD.

Richard Feldman (Sep 04 2026 at 02:11):

oh we're going to add floating point SIMD, just haven't gotten to it yet. Is that blocking you?

Dan G Knutson (Sep 04 2026 at 21:43):

Not blocking! I'm not deep in yet.

I could see other platforms having their own pure-ish things that would be out-of-scope though. That sort of platform-provided custom data transformation just another category that would use a List.map!

Notification Bot (Sep 05 2026 at 01:37):

A message was moved from this topic to #ideas > `List.has_any_match` and `List.for_each_try` by Luke Boswell.

Last updated: Sep 24 2026 at 15:59 UTC